V. 2 References

This list gathers together the book's external evidence base: the peer-reviewed, citable literature behind the clinical claims. The main text of the book is written in patient-friendly language and does not replace these sources – here the interested reader (and the treating physician) will find the foundation.

References

[001] Seekatz A, Safdar N, Khanna S. The role of the gut microbiome in colonization resistance and recurrent. Therapeutic advances in gastroenterology. 2022. Link

Colonization resistance of the gut microbiota and FMT therapy in rCDI — A healthy microbiota inhibits C. difficile colonization (nutrient competition, bile acids, SCFAs, bacteriocins). Antibiotics → dysbiosis → CDI. FMT restores diversity. Monoclonal antibodies do not treat dysbiosis.

[002] Britton R, Young V. Role of the intestinal microbiota in resistance to colonization by Clostridium difficile. Gastroenterology. 2014. Link

Intestinal microbiota and C. difficile colonization resistance — fundamental mechanisms — The native microbiota inhibits germination and growth of C. difficile spores. Antibiotics impair this defense. Key mechanisms: bile acid metabolism, nutrient competition. FMT restores colonization resistance.

[003] Reed AD, Theriot CM. Contribution of Inhibitory Metabolites and Competition for Nutrients to Colonization Resistance against Clostridioides difficile by Commensal Clostridium**. Microorganisms. 2021. Link

This review examines how commensal *Clostridium* species mediate colonization resistance against C. difficile. Commensal *Clostridia* modify primary bile acids into secondary bile acids that suppress C. difficile spore germination and vegetative outgrowth. They additionally produce antimicrobial peptides and short-chain fatty acids that directly inhibit C. difficile and compete for limiting nutrients such as proline, important for C. difficile growth via Stickland fermentation. Loss of commensal *Clostridia* after broad-spectrum antibiotics is a key mechanistic step toward CDI susceptibility. The authors conclude from this that new therapies against CDI are urgently needed; the clinical validation of defined *Clostridium* consortia comes not from this review but from the VE303 phase 2 trial [56].

[004] Chilton C, Viprey V, Normington C, Moura I, Buckley A, Freeman J, Davies K, Wilcox M. Clostridioides difficile pathogenesis and control. Nature reviews. Microbiology. 2026. Link

C. difficile pathogenesis, microbiota dysbiosis, and the role of FMT — Comprehensive review: antibiotic-induced dysbiosis → germination of C. difficile spores → toxin production → colitis. A healthy microbiota provides colonization resistance. Newer microbiota therapies as alternatives to FMT.

[005] Kelly C, Fischer M, Allegretti J, LaPlante K, Stewart D, Limketkai B, Stollman N. ACG Clinical Guidelines: Prevention, Diagnosis, and Treatment of Clostridioides difficile Infections. The American journal of gastroenterology. 2021. Link

According to the 2021 ACG guideline, FMT is part of standard care for rCDI; strongly recommended after ≥2 recurrences — American College of Gastroenterology's latest CDI guidelines: FMT strongly recommended after ≥2 CDI recurrences; capsule and colonoscopic administration are equivalent; detailed donor screening and storage protocol; COVID-era updates regarding FMT safety also incorporated.

[006] Feuerstadt P, Louie TJ, Lashner B et al. SER-109, an Oral Microbiome Therapy for Recurrent Clostridioides difficile Infection. New England Journal of Medicine. 2022. Link

This phase III RCT (ECOSPOR III) tested SER-109, an oral microbiome therapeutic of purified Firmicutes spores, in adults with ≥3 CDI episodes (inclusive of the qualifying acute episode). After standard-of-care antibiotics, patients received SER-109 or placebo (4 capsules daily for 3 days). Diagnosis required toxin testing at trial entry, with stratification by age and antibiotic. The primary efficacy endpoint was reduced risk of CDI recurrence at 8 weeks. SER-109 achieved significant superiority over placebo for sustained clinical response. Analyses also documented microbiome engraftment and shifts in microbial metabolites consistent with the spore-formulation mechanism. The trial supported FDA approval of SER-109 (Vowst) as the first oral microbiome therapeutic for recurrent CDI.

[007] Chilton C, Pickering D, Freeman J. Microbiologic factors affecting Clostridium difficile recurrence. Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases. 2018. Link

Microbiological causes of C. difficile recurrence — spore persistence and dysbiosis — Low bacterial diversity correlates with clinical rCDI. Spore persistence + germination is the key to recurrence. FMT and microbiota therapies are increasingly investigated. Targeted antibiotics (fidaxomicin) + microbiota restoration form the combined approach.

[008] Kao D, Roach B, Silva M et al. Effect of Oral Capsule– vs Colonoscopy-Delivered Fecal Microbiota Transplantation on Recurrent Clostridium difficile Infection: A Randomized Clinical Trial. JAMA. 2017. Link

Noninferiority randomized trial in 116 adults with recurrent CDI across three Canadian academic centres comparing oral capsule FMT with colonoscopy-delivered FMT (enrolment 2014–2016; noninferiority margin 15%). The study tested whether less invasive capsule delivery matches colonoscopy in preventing further CDI recurrence. Results support clinical equivalence between routes, enabling broader and lower-burden access to FMT for recurrent CDI.

[009] Ramai D, Zakhia K, Fields PJ, Ofosu A, Patel G, Chang S. Fecal Microbiota Transplantation (FMT) with Colonoscopy Is Superior to Enema and Nasogastric Tube While Comparable to Capsule for the Treatment of Recurrent Clostridioides difficile Infection: A Systematic Review and Meta-Analysis. Digestive Diseases and Sciences. 2021. Link

Systematic review and meta-analysis of whether the delivery route matters in FMT for recurrent C. difficile infection. Twenty-six studies with 1309 patients were drawn from three databases (PubMed, EMBASE, CINAHL): colonoscopy in 16 studies (483 patients), nasogastric tube in 5 (149), enema in 4 (360) and capsules in 4 (301). Pooled cure rates were: colonoscopy 94.8 percent, capsule 92.1 percent, enema 87.2 percent, nasogastric/nasoduodenal tube 78.1 percent. Conclusion: colonoscopic delivery is superior to enema and tube delivery but comparable to capsules — that is, the least burdensome route costs nothing in efficacy. Sample preparation (fresh or frozen) and donor relationship did not affect the outcome.

[010] Gregory AL, Pensinger DA, Hryckowian AJ. A short chain fatty acid-centric view of Clostridioides difficile pathogenesis. PLoS Pathog. 2021. Link

This review synthesizes the role of short-chain fatty acids (SCFAs) in C. difficile colonization resistance. The gut microbiome produces acetate, propionate and butyrate via fiber fermentation; these SCFAs maintain epithelial barrier function, modulate immunity and signal directly to C. difficile. The authors propose a conceptual model in which C. difficile senses the SCFAs themselves as a marker of a healthy, competitive gut environment and, in response, increases toxin production in order to sustain the dysbiotic state that favours it. SCFAs influence toxin production and competition with commensals. The review argues that targeting SCFA pathways — through dietary intervention, next-generation probiotics or other targeted approaches — offers a precision, non-antibiotic strategy against CDI distinct from both antibiotics and faecal transplant.

[011] Donohoe DR, Garge N, Zhang X, Sun W, O'Connell TM, Bunger MK, Bultman SJ. The microbiome and butyrate regulate energy metabolism and autophagy in the mammalian colon. Cell Metabolism. 2011. Link

Mouse study comparing colonocytes from germ-free and conventionally colonised animals to establish where the colonic lining gets its energy. Germ-free colonocytes are in an energy-deprived state, with reduced expression of TCA-cycle enzymes, lower oxidative phosphorylation and ATP, leading to AMPK activation and autophagy; adding butyrate restores mitochondrial respiration. This is the canonical evidence that bacterially produced butyrate is the primary energy source of the colonic epithelium — the mechanism by which dietary fibre directly feeds the gut lining and maintains the barrier.

[012] Imhann F, Bonder MJ, Vich Vila A et al. Proton pump inhibitors affect the gut microbiome. Gut. 2016. Link

Imhann and colleagues' 2016 Gut paper reports that proton pump inhibitor (PPI) use significantly alters the human gut microbiota. Combining three population cohorts (>1800 individuals) with 16S rRNA sequencing, the authors show that PPI users have decreased microbial diversity and consistent shifts in 20% of bacterial taxa: increases in oral-cavity bacteria (Streptococcaceae, Enterococcaceae), Enterobacteriaceae and *Clostridium* difficile, alongside decreases in commensals such as Ruminococcaceae and Bifidobacteriaceae. These shifts mechanistically explain epidemiological associations between PPI use and CDI, enteric infection, hepatic encephalopathy and SIBO. The work supports prudent PPI prescribing and deprescription efforts.

[013] Jackson MA, Goodrich JK, Maxan ME et al. Proton pump inhibitors alter the composition of the gut microbiota. Gut. 2016. Link

This twin study analyzed faecal 16S rRNA from 1827 healthy twins to test the association of proton pump inhibitor (PPI) use with gut microbiota, with replication in an interventional cohort. PPI users showed significantly lower abundance of gut commensals and lower microbial diversity, alongside a significant increase in oral and upper-GI tract commensals. The findings support a population-scale link between PPI use and gut microbiota disruption, providing a plausible mechanism for the increased enteric infection risk associated with PPIs.

[014] Whelan K, Bancil AS, Lindsay JO, Chassaing B. Ultra-processed foods and food additives in gut health and disease. Nature Reviews Gastroenterology & Hepatology. 2024. Link

Critical review of how ultra-processed foods (UPFs) and the additives they contain affect gut health. The link between UPF-rich diets and gut disease — inflammatory bowel disease, colorectal cancer, irritable bowel syndrome — rests mainly on observational epidemiology, whereas the effects of individual additives (emulsifiers, sweeteners, colours, micro- and nanoparticles) come largely from in vitro and animal work showing impacts on the gut microbiome, intestinal permeability and inflammation. The authors stress that human intervention studies remain scarce, so the direction of the association is well supported while the size of the effect is still uncertain.

[015] Marcella C, Cui B, Kelly CR, Ianiro G, Cammarota G, Zhang F. Systematic review: the global incidence of faecal microbiota transplantation-related adverse events from 2000 to 2020. Aliment Pharmacol Ther. 2021. Link

Systematic review of FMT safety summarizing adverse events (AEs) over 20 years from 129 studies including 4,241 patients and 5,688 FMT courses (search of EMBASE, MEDLINE, Cochrane, CNKI, Wanfang from 2000 to 2020). AEs were classified as delivery-related or microbiota-related. The review provides the largest aggregate FMT safety dataset to date and supports the overall favourable safety profile of FMT for recurrent CDI, while flagging that complications may be under-reported in the literature.

[016] Cammarota G, Ianiro G, Tilg H et al. European consensus conference on faecal microbiota transplantation in clinical practice. Gut. 2017. Link

European consensus conference developing evidence-based recommendations on FMT for clinical practice, with 28 experts from 10 countries collaborating in working groups. Statements were generated through evidence-based review, evaluated electronically via a Delphi process, and finalized in a plenary consensus session. Recommendations cover FMT indications, donor selection, faecal material preparation, clinical management, faecal delivery, and minimum requirements for establishing an FMT centre. Provides the European standardization framework for safe and governed FMT delivery.

[017] van Prehn J, Reigadas E, Vogelzang EH, Bouza E, Kuijper EJ et al. European Society of Clinical Microbiology and Infectious Diseases: 2021 update on the treatment guidance document for Clostridioides difficile infection in adults. Clinical Microbiology and Infection. 2021. Link

ESCMID 2021 treatment guidance for C. difficile infection in adults. Metronidazole is no longer recommended where fidaxomicin or vancomycin is available; fidaxomicin is the preferred agent for an initial episode and for the first recurrence; for a second or further recurrence, faecal microbiota transplantation (FMT) or bezlotoxumab in addition to standard-of-care antibiotics is preferred. Compared with the previous edition, emphasis shifts from disease severity to risk of recurrence: treatment strategy is determined by the individual patient's recurrence risk. This supports triage that measures prognostic risk alongside current symptoms.

[018] Suez J, Zmora N, Zilberman-Schapira G, Mor U, Dori-Bachash M et al. Post-Antibiotic Gut Mucosal Microbiome Reconstitution Is Impaired by Probiotics and Improved by Autologous FMT. Cell. 2018. Link

Human and mouse study of what happens to the gut mucosal microbiome after a course of antibiotics. Three routes were compared: spontaneous recovery, an 11-strain probiotic preparation, and autologous faecal transplantation, that is, return of the person's own flora frozen before the antibiotic. The probiotic colonised the mucosa but delayed the return of the indigenous microbiome and of host mucosal gene expression, and the difference persisted for months. Autologous transplantation, by contrast, produced near-complete recovery within days. Conclusion: after antibiotics a probiotic is not a neutral supplement but may slow the return of the native flora; it is a full microbiota graft that replaces the missing community.

[019] Youngster I, Russell GH, Pindar C, Ziv-Baran T, Sauk J, Hohmann EL. Oral, capsulized, frozen fecal microbiota transplantation for relapsing Clostridium difficile infection. JAMA. 2014. Link

Twenty patients with relapsing C. difficile infection received encapsulated stool from prescreened donors, stored frozen at -80 degrees C: 15 capsules on each of 2 consecutive days. No serious adverse event attributable to the treatment occurred. Diarrhoea resolved in 14 patients (70 percent) after a single course; after re-treatment of the six non-responders the overall figure was 90 percent (18/20). The daily number of bowel movements fell from a median of 5 before treatment to 2 by day 3 and 1 by week 8. This was the first study to obtain results comparable to procedural delivery using frozen, capsulised, orally administered FMT — without sedation or endoscopy.

[020] Lewis SJ, Heaton KW. Stool form scale as a useful guide to intestinal transit time. Scandinavian Journal of Gastroenterology. 1997. Link

The original validation of the Bristol Stool Form Scale. Whole-gut transit time was measured with radio-opaque marker pellets in 66 volunteers, who kept a diary of stool form on a 7-point scale and of defecation frequency. Transit time correlated most closely with stool form (r = -0.54), more strongly than with stool frequency or stool output. When transit time was altered with senna and with loperamide, stool form tracked the change (r = -0.65). Conclusion: recording stool form is a simple and responsive way to monitor change in bowel function — which is why it is suitable for the patient's own diary.

[021] Thaiss CA, Zeevi D, Levy M, Zilberman-Schapira G, Elinav E et al. Transkingdom control of microbiota diurnal oscillations promotes metabolic homeostasis. Cell. 2014. Link

The composition and function of the gut microbiota follow a daily rhythm: bacterial abundance and metabolic activity oscillate across the light-dark cycle, and this oscillation is driven chiefly by the host's feeding rhythm. When the rhythm is disrupted — modelled here in mice and in human samples after intercontinental flight — microbiota oscillation is abolished and dysbiosis develops; transferring the arrhythmic flora into germ-free mice induces metabolic disturbance. Conclusion: a regular daily rhythm is one precondition of microbiota stability — hence the value of a fixed wake time and morning light from the first days of treatment.

[022] Eswaran S, Muir J, Chey WD. Fiber and functional gastrointestinal disorders. American Journal of Gastroenterology. 2013. Link

Review of the role of fibre in functional bowel disorders. The authors organise fibres by solubility and fermentability and stress that these two properties decide which fibre suits a given patient. Fibre ferments partly or completely in the distal small bowel and colon, producing short-chain fatty acids and gas, and thereby affecting gut function and sensation. Where fibre is recommended for functional bowel disease, the evidence best supports a soluble, gel-forming supplement (ispaghula, psyllium). Even when used judiciously, however, fibre can worsen abdominal distension, flatulence, constipation and diarrhoea, so the dose should be built up gradually.

[023] McDonald LC, Gerding DN, Johnson S, Bakken JS, Carroll KC et al. Clinical Practice Guidelines for Clostridium difficile Infection in Adults and Children: 2017 Update by the Infectious Diseases Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA). Clinical Infectious Diseases. 2018. Link

Comprehensive IDSA/SHEA clinical practice guideline on the diagnosis, treatment and prevention of C. difficile infection in adults and children. It defines severity categories (non-severe, severe, fulminant) and characterises fulminant disease by hypotension or shock, ileus or toxic megacolon — findings that require inpatient care, intravenous therapy and surgical consultation. For multiply recurrent infection in which antibiotic therapy has repeatedly failed, faecal microbiota transplantation is recommended. This document provides the international frame to which the book's red flags and hospital-referral signs are aligned.

[024] Hoffmann DE, Javitt GH, Kelly CR, Keller JJ, Baunwall SMD, Hvas CL. Fecal microbiota transplantation: a tale of two regulatory pathways. Gut Microbes. 2025. Link

A joint analysis by lawyers and clinicians of how faecal microbiota transplantation came to sit on two divergent regulatory pathways. In the United States it is handled as a drug (investigational new drug, or licensed product); in Europe it falls under the framework for substances of human origin (SoHO). The authors work through what this means for donor screening, traceability, access and liability. What both pathways share: FMT is not a freely available preparation but a procedure tied to medical supervision and a controlled institutional setting — whichever legal route a given country follows.

[025] Rodriguez J, Cordaillat-Simmons M, Pot B, Druart C. The regulatory framework for microbiome-based therapies: insights into European regulatory developments. npj Biofilms and Microbiomes. 2025. Link

Review of the European regulatory framework for microbiome-based therapies. The paper separates live biotherapeutic products (LBPs), which can be authorised as medicines, from donor-derived substances, which fall under the EU framework for substances of human origin (SoHO) — faecal microbiota transplantation among them. It stresses that donor screening, traceability and clinical oversight are minimum requirements, and that member-state practice can differ within the common frame. This is the international background to which the book's phrasing „tied to medical supervision and an institutional setting" is aligned.

[026] Riddle MS, DuPont HL, Connor BA. ACG Clinical Guideline: Diagnosis, Treatment, and Prevention of Acute Diarrheal Infections in Adults. American Journal of Gastroenterology. 2016. Link

American College of Gastroenterology clinical guideline on the diagnosis, treatment and prevention of acute diarrhoeal infection in adults. The foundation of care in every form is fluid and electrolyte replacement: oral, with generous fluid and salt intake, in mild and moderate cases, and intravenous in severe dehydration. The guideline sets out the signs by which dehydration is recognised and the groups at risk, and stresses that rehydration is not adjunctive but primary treatment — which is what supports deliberate fluid replacement after every loose stool during the course. The guideline also distinguishes severity levels: **in mild, self-limiting diarrhoea ordinary fluid and food intake is generally sufficient**, whereas **with significant or prolonged fluid loss — particularly in older and vulnerable patients — an oral rehydration solution containing electrolytes is recommended**, not water alone. This is the source for the III.7 claim that plain water and a varied diet suffice in mild diarrhoea, while salt must also be replaced in frequent or persistent diarrhoea. **LIMITATION:** the guideline concerns acute infectious diarrhoea; it does not separately address post-FMT convalescence.

[028] Johnson S, Lavergne V, Skinner AM, Gonzales-Luna AJ, Garey KW, Kelly CP, Wilcox MH. Clinical Practice Guideline by the Infectious Diseases Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA): 2021 Focused Update Guidelines on Management of Clostridioides difficile Infection in Adults. Clinical Infectious Diseases. 2021. Link

A focused update of the 2017 IDSA/SHEA guideline, limited to treatment recommendations. The principal change is that fidaxomicin is now preferred over vancomycin for an initial episode — a conditional recommendation with moderate certainty — because although initial cure is similar, sustained cure is better. For recurrent episodes fidaxomicin is likewise preferred, as is a tapered and pulsed vancomycin regimen. Bezlotoxumab is offered as an adjunct for patients at high risk of recurrence. The guideline states explicitly that vancomycin remains an acceptable choice where fidaxomicin is unavailable, and metronidazole has receded even for mild disease. For the SIS the guideline matters because it confirms that the treatment decision depends not only on current severity but on the risk of recurrence — the duality that underlies the acute and prognostic subscores of the SIS.

[029] van Nood E, Vrieze A, Nieuwdorp M, Fuentes S, Zoetendal EG, de Vos WM, Visser CE, Kuijper EJ, Bartelsman JF, Tijssen JG, Speelman P, Dijkgraaf MG, Keller JJ. Duodenal infusion of donor feces for recurrent Clostridium difficile. The New England Journal of Medicine. 2013. Link

The first randomised controlled trial comparing faecal microbiota transplantation with standard antibiotic therapy in recurrent *Clostridioides difficile* infection. Patients were assigned to three arms: donor faeces given through a duodenal tube after a short course of vancomycin, vancomycin alone, or vancomycin with bowel lavage. The trial was stopped early because the difference was so large: in the transplantation arm 81 percent of patients were cured after the first infusion and 94 percent including repeat infusions, against 31 and 23 percent in the two vancomycin arms. After treatment the diversity of the patients' faecal flora came to resemble that of the donors. This paper turned microbiota transplantation into an evidence-based treatment and is the starting point for the dosing regimen of the present protocol.

[031] Lessa FC, Mu Y, Bamberg WM, Beldavs ZG, Dumyati GK, Dunn JR, Farley MM, Holzbauer SM, Meek JI, Phipps EC, Wilson LE, Winston LG, Cohen JA, Limbago BM, Fridkin SK, Gerding DN, McDonald LC. Burden of Clostridium difficile infection in the United States. N Engl J Med. 2015. Link

Population-based surveillance from ten US geographic areas in 2011 estimated the national CDI burden at 453,000 infections and 29,300 deaths annually. The study established that approximately two-thirds of cases were healthcare-associated, with the hypervirulent NAP1 strain disproportionately represented. Recurrence affected 83,000 patients in the same year. These figures underline why CDI remains a high-priority target for ecologically restorative therapies rather than antibiotic-only management.

[032] Guh AY, Mu Y, Winston LG, Johnston H, Olson D, Farley MM, Wilson LE, Holzbauer SM, Phipps EC, Dumyati GK, Beldavs ZG, Kainer MA, Karlsson M, Gerding DN, McDonald LC; Emerging Infections Program Clostridioides difficile Infection Working Group. Trends in U.S. Burden of Clostridioides difficile Infection and Outcomes. N Engl J Med. 2020. Link

Updated US epidemiological surveillance demonstrating that the burden of healthcare-associated CDI declined substantially between 2011 and 2017 – by 36 percent according to the adjusted estimate (95% CI 24 to 54), according to the authors primarily as a result of the decline of ribotype 027 and, alongside it, improved infection control – while community-associated CDI remained stable. The estimated burden of first recurrences and of in-hospital mortality, however, did not change meaningfully. The authors conclude that better identification of patients at high risk of recurrence is needed, together with further strengthening of infection control and antibiotic stewardship; the paper does not discuss microbiota-restorative therapy. The unchanged burden of recurrences is the clinical gap that compatibility-based MTT addresses.

[033] Dethlefsen L, Relman DA. Incomplete recovery and individualized responses of the human distal gut microbiota to repeated antibiotic perturbation. Proceedings of the National Academy of Sciences of the United States of America. 2011. Link

Stanford-based longitudinal study tracking the gut microbiota of three individuals over 10 months across two consecutive courses of ciprofloxacin, with deep 16S rRNA sequencing. Loss of bacterial diversity was profound and rapid, occurring within 3-4 days of antibiotic initiation, and recovery toward the pre-treatment state was often incomplete months after cessation. Repeated antibiotic exposure produced incremental, non-recoverable shifts in community composition. With over 2,000 citations, this paper is the canonical reference establishing that antibiotic-induced dysbiosis is not a self-correcting disturbance but can leave a lasting ecological imprint – central to the case for MTT in patients with cumulative antibiotic exposure history.

[034] Zmora N, Zilberman-Schapira G, Suez J, Mor U, Dori-Bachash M, Bashiardes S, Kotler E, Zur M, Regev-Lehavi D, Brik RB, Federici S, Cohen Y, Linevsky R, Rothschild D, Moor AE, Ben-Moshe S, Harmelin A, Itzkovitz S, Maharshak N, Shibolet O, Shapiro H, Pevsner-Fischer M, Sharon I, Halpern Z, Segal E, Elinav E. Personalized Gut Mucosal Colonization Resistance to Empiric Probiotics Is Associated with Unique Host and Microbiome Features. Cell. 2018. Link

Companion paper to Suez et al. (2018) demonstrating that probiotic colonisation of the gut mucosa is highly person-specific: some individuals are 'permissive' colonisers, while others are 'resistant', and oral probiotic intake exerted a transient and individually variable effect on mucosal community structure and the gut transcriptome. Stool sampling alone fails to detect this heterogeneity – direct mucosal sampling was required. The result undermines the case for empiric probiotic use as a generic intervention. It also provides the conceptual basis for personalised, compatibility-tested microbiota therapy of the kind operationalised by FindBiome.

[036] Chassaing B, Koren O, Goodrich JK, Poole AC, Srinivasan S, Ley RE, Gewirtz AT. Dietary emulsifiers impact the mouse gut microbiota promoting colitis and metabolic syndrome. Nature. 2015. Link

Landmark Nature paper showing that two ubiquitous dietary emulsifiers – carboxymethylcellulose (CMC, E466) and polysorbate-80 (P80, E433) – induced low-grade intestinal inflammation even at relatively low concentrations, altered microbiota composition, and produced obesity/metabolic syndrome in wild-type mice. The authors themselves note that the extent of human emulsifier consumption is not tracked, but that, given how widespread emulsifiers are in food production, actual human exposure may exceed the 1.0 percent level used in the experiment. In mice predisposed to colitis, the same compounds triggered overt colonic inflammation. The authors propose emulsifier exposure as a contributor to the post-1950 rise in IBD and metabolic disease. A corrigendum has been issued for the paper (Corrigendum: *Nature* 2016;536(7615):238). This is the central evidence cited in Section 8.3 of this Guide regarding industrial food production as a chronic input into dysbiosis.

[037] Chassaing B, Van de Wiele T, De Bodt J, Marzorati M, Gewirtz AT. Dietary emulsifiers directly alter human microbiota composition and gene expression ex vivo potentiating intestinal inflammation. Gut. 2017. Link

Follow-up to Chassaing 2015 extending the findings from mice to a human-microbiota model (the M-SHIME ex vivo system). Both emulsifiers increased the pro-inflammatory potential of the microbiota, demonstrably so through elevated flagellin levels; the composition of the community, however, was altered only by P80, while the effect of CMC operated through microbiota gene expression. The rise in lipopolysaccharide levels occurred only with P80, and at higher doses. When a suspension of the emulsifier-treated microbiota was administered to immunodeficient (RAG−/−) mice, serum IL-6 levels rose significantly. The work confirms that the murine findings translate to human gut ecology and reinforces the argument that dietary reform is a clinical, not an aesthetic, component of the maintenance phase.

[044] Wang S, Xiang L, Li F, Deng W, Lv P, Chen Y. Butyrate Protects against Clostridium difficile Infection by Regulating Bile Acid Metabolism. Microbiol Spectr. 2023. Link

Mechanistic CDI study showing that butyrate, a short-chain fatty acid produced by commensal Firmicutes, exerts a protective effect against CDI through multiple synergistic pathways: enhanced gut barrier integrity, anti-inflammatory action, and modulation of bile acid metabolism via bile salt hydrolase regulation and FXR activation. CDI patients have markedly reduced fecal butyrate compared to controls. The findings establish a metabolic mechanism by which a healthy, diverse microbiota resists CDI colonisation – and by which a dysbiotic microbiota becomes permissive. This underpins the SCFA-related reasoning in Section 2.2 about depleted SCFA synthesis in chronic dysbiosis.

[046] Chen RA, Wu WK, Panyod S, Liu PY, Chuang HL, Chen YH, Lyu Q, Hsu HC, Lin TL, Shen TD, Yang YT, Zou HB, Huang HS, Lin YE, Chen CC, Ho CT, Lai HC, Wu MS, Hsu CC, Sheen LY. Dietary Exposure to Antibiotic Residues Facilitates Metabolic Disorder by Altering the Gut Microbiota and Bile Acid Composition. mSystems. 2022. Link

Empirical study quantifying how chronic dietary exposure to subtherapeutic antibiotic residues (specifically tylosin at theoretical maximum daily intake, or TMDI, doses) alters gut microbiota composition and bile acid metabolism, producing measurable metabolic dysfunction in animal models. The obesity-related phenotype was transferable to germ-free recipient mice, indicating the effect is mediated by the altered microbiota itself. Early-life exposure produced lasting metabolic consequences via FGF15 signalling. Provides the most current empirical evidence cited in Section 8.2 supporting the categorical exclusion of conventional antibiotic-treated animal protein from donor and post-MTT recipient diets.

[048] Weingarden A, González A, Vázquez-Baeza Y, Weiss S, Humphry G, Berg-Lyons D, Knights D, Unno T, Bobr A, Kang J, Khoruts A, Knight R, Sadowsky MJ. Dynamic changes in short- and long-term bacterial composition following fecal microbiota transplantation for recurrent Clostridium difficile infection. Microbiome. 2015. Link

Longitudinal microbiome characterisation following FMT in four patients with recurrent CDI, sampling daily for 28 days and weekly to 84 days post-treatment, over a total of 151 days. The recipient microbiota rapidly normalised from a markedly dysbiotic state to a healthy-range composition within days. Composition continued to change thereafter, diverging from the original donor implant material and fluctuating dynamically over both the short and the long term – while remaining throughout within the cloud of healthy microbiota. The paper supports the framing in this Guide that successful MTT produces a self-sustaining recipient ecology, not a permanent donor-tracked imprint.

[049] Hecker MT, Rosero C, Mendo-Lopez R, Wilson BM, Torres-Teran MM, Donskey CJ. Long-Term Follow-Up After Fecal Microbiota Transplantation via Freeze-Dried Capsules for Recurrent Clostridioides difficile Infection. Pathog Immun. 2026. Link

This 2026 retrospective cohort study from two US academic hospitals followed 129 patients with recurrent CDI treated with freeze-dried oral FMT capsules over a median follow-up of 182 weeks – the longest published follow-up of capsule-based FMT to date and a near-perfect match for the lyophilised capsule format used in the MicroBiome Bank protocol. Of the cohort, 89% had experienced three or more prior CDI episodes; at three months, 80% of patients had no recurrence, and the 20% who failed initial therapy were largely successfully managed with repeat FMT. Across the long follow-up, only 17% of patients experienced any additional CDI episode, and most of those were again successfully managed with repeat FMT. The study confirms that lyophilised oral capsule FMT is a durable, repeatable, real-world therapy for recurrent CDI in heavily pre-treated patients.

[052] Daneri L, Urbano A, Escudero-Sánchez R, Halperin AV, Moreno-Blanco A, Corbacho MD, Suárez-Carantoña C, Rodríguez-Jiménez C, Serrano-Villar S, del Campo R, Cobo J. Lyophilised fecal microbiota transfer in capsules for recurrent Clostridioides difficile infection. Int J Antimicrob Agents. 2025. Link

This 2025 Spanish retrospective cohort study covered 36 patients with multiply-recurrent CDI and 38 procedures, with a median age of 78.5 years and a median of four prior episodes; the great majority of the authors work at a single Madrid centre. The lyophilised, encapsulated formulation achieved a 75 percent cure rate at three months in this elderly, refractory population, with no serious adverse events attributable to the procedure. The authors note that FMT failures could be successfully resolved by additional therapy that need not necessarily be a further FMT, supporting flexible escalation pathways. The paper validates capsule-based, off-the-shelf FMT as a logistically simpler alternative to colonoscopic delivery – directly aligned with the format used in the MicroBiome Bank protocol described in Section IV of this Guide.

[058] Carlson TJ, Gonzales-Luna AJ, Garey KW. Fulminant Clostridioides difficile Infection: A Review of Treatment Options for a Life-Threatening Infection. Semin Respir Crit Care Med. 2022. Link

A review of the treatment options for fulminant Clostridioides difficile infection. The authors put the fulminant form at 3–5% of all CDI cases and its associated mortality at 30–40% — an order of magnitude above CDI mortality at population level. The review works through the pharmacological and surgical options for managing the fulminant case. In this document the item supplies the mortality figure for the terminal station of Section II. 1.; its denominator is all fulminant cases, not only the patients who proceed to surgery.

[061] Benedict C, Vogel H, Jonas W et al. Gut microbiota and glucometabolic alterations in response to recurrent partial sleep deprivation in normal-weight young individuals. Mol Metab. 2016. Link

Randomized within-subject crossover study in 9 normal-weight men comparing two nights of partial sleep deprivation (PSD; 02:45–07:00) with two nights of normal sleep (22:30–07:00) under standardized in-lab meal and exercise conditions. Faecal samples were collected and oral glucose tolerance was tested. The study assessed whether short-term sleep loss alters gut microbiota composition and metabolic function, providing early human evidence linking sleep restriction to acute microbiota shifts and insulin resistance.

[062] Hamer HM, Jonkers D, Venema K, Vanhoutvin S, Troost FJ, Brummer RJ. The role of butyrate on colonic function. Aliment Pharmacol Ther. 2008. Link

Narrative review summarizing the bioactivity of butyrate — a SCFA produced by colonic microbial fermentation of dietary fibre — and its mechanisms in human colonic function. Butyrate is the primary energy source for colonocytes and modulates inflammation, carcinogenesis, mucosal barrier integrity, oxidative stress, permeability, and satiety. The review consolidates evidence on butyrate as a central effector of colonic homeostasis and a target for dietary interventions in colonic disease.

[063] Wastyk HC, Fragiadakis GK, Perelman D et al. Gut-microbiota-targeted diets modulate human immune status. Cell. 2021. Link

17-week randomized prospective trial (n=18/arm) in healthy adults comparing high-fibre versus high-fermented-food diets with multi-omics microbiome and host immune profiling. The high-fibre diet increased microbiome-encoded glycan-degrading CAZymes despite stable diversity. The high-fermented-food diet increased microbiome diversity and decreased multiple inflammatory markers. Findings demonstrate diet-specific microbiome–immune effects and support fermented foods as a strong, diversity-promoting modulator of the gut–immune axis.

[064] Marco ML, Heeney D, Binda S et al. Health benefits of fermented foods: microbiota and beyond. Curr Opin Biotechnol. 2017. Link

Review of fermented foods, among the first processed food products consumed by humans (yogurt, cultured milk, wine, beer, sauerkraut, kimchi, fermented sausage). Originally valued for shelf life and palatability, fermented foods are now recognized as having enhanced nutritional and functional properties through substrate transformation and bioactive end-product formation. Many fermented foods contain living microorganisms with potential health effects. The review consolidates fermented foods as a microbiome-relevant dietary category.

[065] Calder, P. C. Omega-3 fatty acids and inflammatory processes: from molecules to man. Biochem Soc Trans. 2017. Link

Review of omega-6 and omega-3 fatty acid roles in inflammation. EPA and DHA from oily fish or fish-oil supplements partly inhibit leucocyte chemotaxis, adhesion molecule expression, leucocyte-endothelial interactions, and the production of arachidonic-acid-derived eicosanoids and pro-inflammatory cytokines. EPA-derived eicosanoids are typically less potent than those from arachidonic acid, and EPA/DHA give rise to anti-inflammatory and inflammation-resolving mediators (resolvins, protectins, maresins), supporting their use in inflammatory conditions.

[066] Costantini L, Molinari R, Farinon B, Merendino N. Impact of Omega-3 Fatty Acids on the Gut Microbiota. Int J Mol Sci. 2017. Link

Long-term dietary habits shape host-specific gut microbiota, but dietary fat effects are less well characterised than those of carbohydrates. The few adult human omega-3 PUFA supplementation studies show consistent changes: decreased Faecalibacterium, increased Bacteroidetes and butyrate-producing Lachnospiraceae. Because dysbiosis of these taxa occurs in inflammatory bowel disease, omega-3 PUFAs may exert a beneficial effect by restoring microbial composition and increasing anti-inflammatory short-chain fatty acid production.

[067] Suez J, Korem T, Zeevi D et al. Artificial sweeteners induce glucose intolerance by altering the gut microbiota. Nature. 2014. Link

Non-caloric artificial sweeteners (NAS) induced glucose intolerance in mice and humans via compositional and functional changes in the gut microbiota. Antibiotic treatment abrogated the deleterious metabolic effects, and germ-free mice receiving faecal transplants from NAS-consuming mice (or NAS-incubated microbiota) developed glucose intolerance. NAS-altered microbial metabolic pathways were linked to metabolic disease susceptibility, with similar dysbiosis and glucose intolerance demonstrated in healthy human subjects. The findings call for reassessment of widespread NAS use.

[068] Desai MS, Seekatz AM, Koropatkin NM et al. A dietary fiber-deprived gut microbiota degrades the colonic mucus barrier and enhances pathogen susceptibility. Cell. 2016. Link

In gnotobiotic mice colonised with a synthetic human gut microbiota, chronic or intermittent dietary fibre deficiency caused the microbiota to use host-secreted mucus glycoproteins as a nutrient source, eroding the colonic mucus barrier. Combined fibre deprivation and a mucus-eroding microbiota allowed greater epithelial access and lethal colitis by the mucosal pathogen Citrobacter rodentium. The findings link diet, microbiome and intestinal barrier dysfunction and identify dietary fibre as a key barrier-protective factor exploitable for therapeutic strategies.

[069] Suez J, Cohen Y, Valdés-Mas R et al. Personalized microbiome-driven effects of non-nutritive sweeteners on human glucose tolerance. Cell. 2022. Link

Randomised controlled trial in 120 healthy adults receiving saccharin, sucralose, aspartame or stevia (in doses below acceptable daily intake) versus glucose-vehicle or no supplement for 2 weeks. All four non-nutritive sweeteners distinctly altered the stool/oral microbiome and plasma metabolome; saccharin and sucralose significantly impaired glycaemic responses. Gnotobiotic mice colonised with microbiomes from top and bottom human responders reproduced donor-specific glycaemic responses, demonstrating that non-nutritive sweeteners can induce person-specific, microbiome-dependent glycaemic alterations.

[070] Halmos EP, Power VA, Shepherd SJ, Gibson PR, Muir JG. A diet low in FODMAPs reduces symptoms of irritable bowel syndrome. Gastroenterology. 2014. Link

Randomised single-blind cross-over trial in 30 IBS patients and 8 controls compared a low-FODMAP diet (<0.5 g/meal) with a typical Australian diet for 21 days each (>=21-day washout). Almost all food was provided. The low-FODMAP arm produced significantly greater reduction in IBS symptoms measured on 0-100 mm visual analogue scales, supporting the low-FODMAP diet as an effective intervention for symptom control in IBS compared with a standard Western diet.

[071] Liang X, FitzGerald GA. Timing the Microbes: The Circadian Rhythm of the Gut Microbiome. J Biol Rhythms. 2017. Link

Review of circadian organisation in the gut microbiome. The mammalian circadian system (master clock and peripheral clocks) coordinates biological processes in response to external cues like the light-dark cycle, but prokaryote chronobiology — outside cyanobacteria — is poorly understood. The review summarises evidence of time-of-day-dependent compositional and functional structure within the gut microbiota, host regulation of these oscillations, and the reciprocal influence of the gut microbiome on host circadian timing.

[072] Chaix A, Zarrinpar A, Miu P, Panda S. Time-restricted feeding is a preventative and therapeutic intervention against diverse nutritional challenges. Cell Metab. 2014. Link

Time-restricted feeding (TRF; 8-9 h food access in the active phase) was tested in mice under diverse obesogenic diets. TRF attenuated metabolic disease across a range of obesogenic diets, with benefits proportional to fasting duration. Protective effects persisted even when weekend ad libitum access interrupted TRF — a regimen relevant to human lifestyle. TRF also stabilised and reversed metabolic disease in mice with preexisting obesity and type 2 diabetes, supporting TRF as both a preventative and therapeutic strategy.

[073] Zarrinpar A, Chaix A, Yooseph S, Panda S. Diet and feeding pattern affect the diurnal dynamics of the gut microbiome. Cell Metab. 2014. Link

The gut microbiome exhibits daily cyclical compositional fluctuations driven by the feeding/fasting cycle. Diet-induced obesity dampens the daily feeding/fasting rhythm and diminishes microbiota cyclical fluctuations. Time-restricted feeding (TRF), in which feeding is consolidated to the nocturnal phase in mice, partially restores cyclical fluctuations and protects against obesity and metabolic disease. TRF preferentially affects bacteria known to influence host metabolism, linking feeding rhythm, microbiome dynamics, and metabolic outcomes.

[074] Irwin MR, Opp MR. Sleep health: reciprocal regulation of sleep and innate immunity. Neuropsychopharmacology. 2017. Link

This review and overview examines reciprocal interactions between sleep disturbances, including insomnia, and the innate immune system. Insomnia complaints, extreme sleep duration and experimental sleep deprivation alter genomic, cellular and systemic markers of inflammation and contribute to inflammaging. Inflammatory mediators in turn reshape homeostatic regulation of sleep continuity and macrostructure. Clinical implications include the link between sleep disturbance and inflammation-related depressive symptoms, and the potential of insomnia-targeted interventions to reverse inflammation. The findings underscore that sleep disturbance is a tractable risk factor for inflammatory disease.

[075] Allen JM, Mailing LJ, Niemiro GM et al. Exercise alters gut microbiota composition and function in lean and obese humans. Med Sci Sports Exerc. 2018. Link

This 6-week endurance training trial in 32 previously sedentary lean (n=18) and obese (n=14) adults assessed exercise-induced changes in gut microbiota composition, function and metabolite output, followed by a 6-week sedentary washout. Training progressed from 30 to 60 minutes at 60-75% of HR reserve, three days per week. Beta-diversity analysis showed that exercise-induced microbiota alterations were dependent on obesity status. The findings indicate that endurance training reshapes the gut microbiota in a host-phenotype-dependent manner, with effects partly reversible upon return to inactivity.

[076] Mayer EA, Tillisch K, Gupta A. Gut/brain axis and the microbiota. J Clin Invest. 2015. Link

This review summarizes preclinical evidence that the gut microbiota influences the bidirectional CNS-ENS-GI axis. Germ-free rodent studies show that microbiota shape emotional behaviour, stress- and pain-modulation systems and brain neurotransmitters. Probiotic and antibiotic perturbations modulate these endpoints in adult animals. Multiple endocrine and neurocrine pathways mediate microbiota-to-brain signalling, while the brain alters microbial composition via the autonomic nervous system. Translation of these findings to healthy humans and gut-brain axis disorders remains limited and is identified as a research priority.

[077] Atarashi K, Suda W, Luo C et al. Ectopic colonization of oral bacteria in the intestine drives TH1 cell induction and inflammation. Science. 2017. Link

This gnotobiotic study showed that salivary Klebsiella strains, when colonizing the gut, are strong inducers of T helper 1 (TH1) cells. These antibiotic-resistant Klebsiella strains colonize when intestinal microbiota are dysbiotic and elicit severe gut inflammation in genetically susceptible hosts. The findings establish the oral cavity as a reservoir for potential intestinal pathobionts that exacerbate disease such as IBD when ectopically colonizing the gut.

[078] Kapil V, Haydar SM, Pearl V, Lundberg JO, Weitzberg E, Ahluwalia A. Physiological role for nitrate-reducing oral bacteria in blood pressure control. Free Radic Biol Med. 2013. Link

This randomized crossover study in 19 healthy volunteers tested whether suppressing oral nitrate-reducing bacteria with chlorhexidine antiseptic mouthwash affects systemic nitrite levels and blood pressure. Blood pressure (clinic, home, 24-hour ambulatory) was measured during a 7-day control period and a 7-day chlorhexidine treatment period. Mouthwash use suppressed oral nitrate-reducing flora, reduced systemic nitrite and significantly increased blood pressure. The findings demonstrate that oral microbiota actively contribute to systemic blood pressure regulation via the enterosalivary nitrate-nitrite-NO pathway.

[079] Hajishengallis, G. Periodontitis: from microbial immune subversion to systemic inflammation. Nat Rev Immunol. 2015. Link

This review discusses how dysbiotic oral microbial communities drive periodontitis and inflammatory pathology at local and distant sites. The authors detail microbial immune subversion mechanisms that tip oral homeostasis to disease. Periodontitis emerges as a dysbiotic inflammatory disease with systemic implications, including links to cardiovascular and other chronic diseases. The findings frame periodontitis treatment as a strategy with potential systemic-health benefits.

[080] Sonnenburg ED, Smits SA, Tikhonov M, Higginbottom SK, Wingreen NS, Sonnenburg JL. Diet-induced extinctions in the gut microbiota compound over generations. . 2016. Link

In mice on a low microbiota-accessible carbohydrate (fiber) diet, gut microbiota diversity declined and the effect compounded across generations: over four generations the low-fiber diet led to cumulative taxon extinctions no longer reversible by dietary fiber reintroduction.

[081] Chang AM, Aeschbach D, Duffy JF, Czeisler CA. Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness. Proc Natl Acad Sci USA. 2015. Link

Average sleep duration and quality have declined, and 90% of US adults report electronic device use in the hour before bed. Short-wavelength-enriched light from these devices can suppress melatonin, shift circadian phase and increase alertness. In a controlled comparison, the authors evaluated the biological effects of reading on a light-emitting e-book device versus a printed book before bedtime, examining melatonin, circadian timing, sleep latency and next-morning alertness. The LE-eBook condition delayed circadian timing, suppressed evening melatonin, lengthened sleep onset and reduced next-morning alertness. The findings indicate that pre-bedtime use of light-emitting screens degrades sleep and circadian alignment.

[082] Kelly JR, Kennedy PJ, Cryan JF, Dinan TG, Clarke G, Hyland NP. Breaking down the barriers: the gut microbiota, intestinal permeability and stress-related psychiatric disorders. Front Cell Neurosci. 2015. Link

The gut-brain axis is positioned as a critical node in stress-related psychiatric disorders, with the gut microbiome modulating brain development, function and behavior through immune, endocrine and neural pathways. Preclinical evidence implicates impaired intestinal barrier function — the so-called leaky gut — as a key mediator linking dysbiosis to chronic low-grade inflammation and disorders such as depression. The gut microbiome regulates intestinal permeability via short-chain fatty acids, mucin production and tight-junction signaling. The review argues that targeting microbiota-driven barrier integrity may offer mechanistic and therapeutic insight into stress-related psychiatric disease.

[083] McDonald D, Hyde E, Debelius JW et al. American Gut: an Open Platform for Citizen Science Microbiome Research. mSystems. 2018. Link

The American Gut Project compared >10 000 citizen-scientist stool samples from the US, UK and Australia with environmental samples using Earth Microbiome Project standardized protocols. Human stool microbiomes showed unexpectedly wide beta-diversity compared with environmental samples. Open data integration enabled discovery of new molecules and untargeted-metabolomic associations with diverse plant intake (a stronger predictor than reductive categorical variables like veganism). The work demonstrates feasibility of mail-shipped, self-collected microbiome samples for reproducing known and revealing new associations, including psychiatric illness links and individual perturbations such as surgery.

[084] Wilson BC, Vatanen T, Cutfield WS, O'Sullivan JM. The Super-Donor Phenomenon in Fecal Microbiota Transplantation. Front Cell Infect Microbiol. 2019. Link

FMT is highly effective for recurrent Clostridium difficile infection but its efficacy in chronic dysbiosis-associated diseases has been modest and variable. Multiple studies suggest FMT outcome depends on stool donor microbial diversity and composition, leading to the concept of FMT 'super-donors'. The review explores keystone species as predictors of FMT success and discusses how host genetics and diet may influence engraftment and maintenance — providing a framework for more targeted, donor-stratified bacteriotherapy.

[085] Targownik LE, Fisher DA, Saini SD. AGA Clinical Practice Update on De-Prescribing of Proton Pump Inhibitors: Expert Review. Gastroenterology. 2022. Link

A clinical update provides Best Practice Advice statements for PPI de-prescribing in ambulatory patients. PPIs are among the most-prescribed medications and are increasingly used for indications with uncertain benefit, contributing to polypharmacy and economic burden. PPI use has been increasingly associated with PPI-associated adverse events (PAAEs). The guidance promotes structured de-prescribing strategies to reduce pill burden, real costs and theoretical risks while ensuring patients with appropriate indications continue therapy.

[086] Chaix A, Manoogian ENC, Melkani GC, Panda S. Time-Restricted Eating to Prevent and Manage Chronic Metabolic Diseases. Annu Rev Nutr. 2019. Link

Molecular clocks are present in almost every cell to anticipate daily recurring and predictable changes, such as rhythmic nutrient availability, and to adapt cellular functions accordingly. At the same time, nutrient-sensing pathways can respond to acute nutrient imbalance and modulate and orient metabolism so cells can adapt optimally to a declining or increasing availability of nutrients. Organismal circadian rhythms are coordinated by behavioral rhythms such as activity-rest and feeding-fasting cycles to temporally orchestrate a sequence of physiological processes to optimize metabolism. Basic research in circadian rhythms has largely focused on the functioning of the self-sustaining molecular circadian oscillator, while research in nutrition science has yielded insights into physiological responses to caloric deprivation or to specific macronutrients. Integration of these two fields into actionable new concepts in the timing of food intake has led to the emerging practice of time-restricted eating. In this paradigm, daily caloric intake is restricted to a consistent window of 8-12 h.

[087] Saha S, Mara K, Pardi D, Khanna S. Long-term Safety of Fecal Microbiota Transplantation for Recurrent Clostridioides difficile Infection. Gastroenterology. 2021. Link

Long-term safety of FMT in rCDI: low infection transmission risk; new diagnoses likely unrelated to FMT — Mayo Clinic 609 patients, 6.8-year prospective data — 609 patients, median 3.7 years follow-up (range 2.0–6.8 years). At 1 year: 9.5% reported a new CDI episode. Long-term, 73 new diagnoses (13% GI, 10% weight gain, 11.8% infection) — all judged unrelated to FMT. Higher diarrhea risk in IBD, dialysis-dependent kidney disease, and patients undergoing repeated FMT.

[088] Yau Y, Lau L, Lui R, Wong S, Guo C, Mak J, Ching J, Ip M, Kamm M, Rubin D, Chan P, Chan F, Ng S. Long-Term Safety Outcomes of Fecal Microbiota Transplantation: Real-World Data Over 8 Years From the Hong Kong FMT Registry. Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association. 2024. Link

Excellent long-term safety profile of FMT based on 8-year registry data: low risk of new disease beyond 12 months; survival of CDI-treated patients significantly better than antibiotic controls — 123 patients, 510 FMTs, median 30.3 months follow-up (max 57.9 months = ~5 years). Beyond 12 months, 21 new diseases in 16 patients — all judged unrelated to FMT. No development of IBD, IBS, allergy, T2DM, or psychiatric disorder. Cumulative survival probability of FMT-treated rCDI patients significantly better than matched antibiotic controls.

[089] Bonomini-Gnutzmann R, Plaza-Díaz J, Jorquera-Aguilera C, Rodríguez-Rodríguez A, Rodríguez-Rodríguez F. Effect of Intensity and Duration of Exercise on Gut Microbiota in Humans: A Systematic Review. International journal of environmental research and public health. 2022. Link

Exercise intensity and duration determine gut microbiota composition; moderate exercise is favorable, while extreme endurance load may cause negative microbiota changes — 13 studies: intense exercise — increased gut permeability, elevated I-FABP, dysbiosis; 7 studies: moderate exercise — increase in microbial diversity and SCFA metabolites; in athletes, more adverse effects at high intensity (IJERPH, 2022).

[090] Kolida S, Meyer D, Gibson GR. A double-blind placebo-controlled study to establish the bifidogenic dose of inulin in healthy humans. Eur J Clin Nutr. 2007. Link

OBJECTIVE: To evaluate the bifidogenic efficacy of two inulin doses in healthy human adults. DESIGN: A double-blind, placebo-controlled, crossover human study. SETTING: Food Microbial Sciences Unit, The University of Reading, Reading, UK. SUBJECTS: Thirty healthy volunteers, 15 men, 15 women (age range 19-35). INTERVENTIONS: Subjects consumed a chocolate drink containing placebo (maltodextrin, 8 g/day), 5 g/day inulin and 8 g/day inulin for a 2-week treatment period. Each treatment was followed by a 1-week washout at the end of which volunteers progressed to the next treatment.

[091] Wu, G. Functional amino acids in nutrition and health. . 2013. Link

The recent years have witnessed growing interest in biochemistry, physiology and nutrition of amino acids (AA) in growth, health and disease of humans and other animals. This results from the discoveries of AA in cell signaling involving protein kinases, G protein-coupled receptors, and gaseous molecules (i.e., NO, CO and H2S). In addition, nutritional studies have shown that dietary supplementation with several AA (e.g., arginine, glutamine, glutamate, leucine, and proline) modulates gene expression, enhances growth of the small intestine and skeletal muscle, or reduces excessive body fat. These seminal findings led to the new concept of functional AA, which are defined as those AA that participate in and regulate key metabolic pathways to improve health, survival, growth, development, lactation, and reproduction of the organisms. Functional AA hold great promise in prevention and treatment of metabolic diseases (e.g., obesity, diabetes, and cardiovascular disorders), intrauterine growth restriction, infertility, intestinal and neurological dysfunction, and infectious disease (including viral infections).

[092] Sutton EF, Beyl R, Early KS et al. Early Time-Restricted Feeding Improves Insulin Sensitivity, Blood Pressure, and Oxidative Stress Even without Weight Loss in Men with Prediabetes. Cell Metabolism. 2018. Link

Cross-over RCT with 8 men with prediabetes: restricting meals to an early 6-hour window (eTRF, 8:00–14:00) for 5 weeks — under energy-matching — significantly improved insulin sensitivity, β-cell response, blood pressure, and oxidative stress compared to a 12-hour control window. Weight loss was NOT required for these favourable metabolic changes, indicating the effect arises from circadian alignment.

[093] Zou T, Zhao Y, Zhou X, Kang Y, Wang X. Insight into the effects of Omega-3 fatty acids on gut microbiota: impact of a balanced tissue Omega-6/Omega-3 ratio. Front Nutr. 2025. Link

Review of how omega-3 fatty acids and a balanced tissue omega-6:omega-3 ratio shape gut microbiota composition and function: a high ratio favours pro-inflammatory/LPS-producing bacteria, a balanced ratio favours SCFA-producers (Bifidobacterium, Roseburia, Lactobacillus); supports a personalized dietary approach based on fatty-acid ratios.

[096] De Schryver AM, Keulemans YC, Peters HP, Akkermans LM, Smout AJ, De Vries WR. Effects of regular physical activity on defecation pattern in middle-aged patients complaining of chronic constipation. Scandinavian Journal of Gastroenterology. 2005. Link

Randomized study in middle-aged, inactive patients with chronic idiopathic constipation: a 12-week regular physical-activity programme (including walking) significantly reduced rectosigmoid and total colonic transit time and improved defecation pattern. The work provides direct clinical evidence that regular movement accelerates gut transit.

[097] Palleja A, Mikkelsen KH, Forslund SK et al. Recovery of gut microbiota of healthy adults following antibiotic exposure. Nature Microbiology. 2018. Link

Shotgun-metagenomic study of 12 healthy men: after a 4-day course of three last-resort antibiotics (meropenem, gentamicin, vancomycin) the gut microbiota largely but incompletely recovered over six months — several common species stayed missing and resistance genes were transiently enriched.

[098] Karmisholt Grosen A et al. Effects of clinical donor characteristics on the success of faecal microbiota transplantation for patients in Denmark with Clostridioides difficile infection: a single-centre, prospective cohort study. The Lancet Microbe. 2025. Link

Single-centre, prospective Danish cohort: clinical donor characteristics — including antibiotic exposure in the 12 months before donation and donation stool consistency — affect FMT success in recurrent C. difficile infection; donor antibiotic use worsens outcomes, supporting strict donor screening.

[099] Deutz NE, Bauer JM, Barazzoni R, Biolo G, Boirie Y, Bosy-Westphal A, Cederholm T, Cruz-Jentoft A, Krznaric Z, Nair KS, Singer P, Teta D, Tipton K, Calder PC. Protein intake and exercise for optimal muscle function with aging: recommendations from the {ESPEN. Clinical Nutrition. 2014. Link

Ageing brings a gradual, progressive loss of muscle mass, strength and physical endurance (sarcopenia), most marked in sedentary older adults. This ESPEN Expert Group review concludes that regular aerobic and resistance exercise counteracts most aspects of sarcopenia, and that adequate protein and energy intake helps limit and treat age-related declines in muscle mass, strength and function. The group recommends a higher dietary protein intake than the traditional 0.8 g/kg/day — about 1.0–1.2 g/kg body weight per day for healthy older adults and 1.2–1.5 g/kg/day for those with acute or chronic illness — combined with physical activity. The aim is to preserve muscle function, mobility and independence in later life.

[100] Kelly CR, Ihunnah C, Fischer M, Khoruts A, Surawicz C, Afzali A, Aroniadis O, Barto A, Borody T, Giovanelli A, Gordon S, Gluck M, Hohmann EL, Kao D, Kao JY, McQuillen DP, Mellow M, Rank KM, Rao K, Ray A, Schwartz MA, Singh N, Stollman N, Suskind DL, Vindigni SM, Youngster I, Brandt L. Fecal Microbiota Transplant for Treatment of {Clostridium. American Journal of Gastroenterology. 2014. Link

Clostridium difficile infection (CDI) is especially dangerous in immunocompromised patients, yet the safety of fecal microbiota transplantation (FMT) in this group had been uncertain. This 16-centre retrospective series studied 80 immunocompromised patients (75 adults, 5 children) whose CDI was recurrent (55%), refractory (11%) or severe/overlapping (34%); causes of immunocompromise included HIV/AIDS, solid-organ transplant, oncologic disease, inflammatory bowel disease immunosuppression and other conditions. The CDI cure rate after a single FMT was 78%, and the procedure was generally safe: serious adverse events within 12 weeks were uncommon and did not indicate FMT-transmitted infection. The authors conclude that FMT is an effective and safe option for CDI even in immunocompromised patients.

[101] Buccigrossi Vittoria, Lo Vecchio Andrea, Bruzzese Eugenia, Russo Carla, Marano Antonella, Terranova Sara, Cioffi Valentina, Guarino Alfredo. Potency of Oral Rehydration Solution in Inducing Fluid Absorption is Related to Glucose Concentration. Scientific Reports. 2020. Link

Oral rehydration solution (ORS) is the key treatment of acute diarrhoea in children: it restores electrolyte balance by stimulating the intestinal sodium/glucose transporter SGLT1 to drive fluid absorption. The authors tested solutions with different sodium and glucose concentrations on Caco-2 intestinal cells using Ussing-chamber electrophysiology during rotavirus-induced secretion. The ESPGHAN ORS (sodium 60 mmol/L, glucose 111 mmol/L) produced a more potent pro-absorptive effect than the WHO ORS, and the effect depended on the sodium/glucose ratio; rotavirus-induced fluid secretion could be reversed toward absorption when sodium fell in the 45–60 mEq/L range and glucose in the 80–110 mM range. The conclusion is that the pro-absorptive potency of ORS depends on its sodium and glucose concentrations.

[102] Laborde Sylvain, Allen MarkS, Borges Uirassu, Iskra Maša, Zammit Nina, You Min, Hosang Thomas, Mosley Emma, Dosseville Fabrice. Psychophysiological effects of slow-paced breathing at six cycles per minute with or without heart rate variability biofeedback. Psychophysiology. 2022. Link

Heart rate variability (HRV) biofeedback — slow-paced breathing (SPB) performed while watching a heart-rate/HRV signal — is increasingly used as an adjunct for many psychological and medical conditions, but its mechanism is unclear. In 112 participants, this study compared SPB at six breaths per minute done with HRV biofeedback (SPB-HRVB) versus without it (SPB-NoHRVB), measuring emotional valence, arousal and control, perceived stress, and the vagally mediated HRV index RMSSD. Both conditions produced the same pre-to-post benefits — a calmer emotional valence, lower arousal, greater emotional control and higher RMSSD — with the biofeedback adding only a slightly more positive overall valence. The authors conclude that slow-paced breathing itself drives most of the psychophysiological benefit and suggest testing longer interventions and different stressors.

[103] Hengel RichardL, Schroeder ClaudiaP, Jo Jinhee, Ritter TimothyE, Nathan RameshV, Gonzales-Luna AnneJ, Obi EngelsN, Dillon RyanJ, Van Anglen LucindaJ, Garey KevinW. Recurrent Clostridioides difficile infection worsens anxiety-related patient-reported quality of life. Journal of Patient-Reported Outcomes. 2022. Link

This patient-reported study measures how health-related quality of life (HrQOL) changes after treatment of Clostridioides difficile infection (CDI), using the anxiety-focused Cdiff32 instrument. Among 144 adults treated with bezlotoxumab, the mean score improved from 26.4 at baseline to 56.4 at 90-day follow-up (higher scores indicate better quality of life). Patients without recurrence improved significantly more (34.1-point increase) than those with recurrent CDI (6.7-point increase; P < 0.001). Recurrent CDI therefore meaningfully worsens anxiety-related quality of life, and the Cdiff32 instrument is useful for assessing these humanistic outcomes.

[104] McFarland, L. V. Use of probiotics to correct dysbiosis of normal microbiota following disease or disruptive events: a systematic review. BMJ Open. 2014. Link

Systematic review of the extent to which probiotics can restore normal microbiota disrupted by disease or antibiotic treatment, covering 63 studies. The result is twofold: individual probiotic strains measurably improved certain microbiota indices, but restoration of the whole community — rebuilding diversity and the missing functional groups — was not achieved in most studies, and the effect was strain-, dose- and baseline-dependent. The paper therefore does not argue against probiotics but for delimiting their scope precisely: delivering a few strains is not the same as replacing a complete, diverse microbiota community. Chapter II.5 of the handbook uses this distinction when separating probiotics from a whole microbiota graft.

[105] Bishehsari F, Post Z, Swanson GR, Keshavarzian A. Circadian Rhythms in Gastroenterology: The Biological Clock's Impact on Gut Health. Gastroenterology. 2025. Link

Review of the role of circadian rhythm in normal gastrointestinal function. The central clock in the hypothalamus and the peripheral clocks in GI organs together orchestrate gut function in response to environmental cycles; this clock is set by cues including light, **sleep** and eating times. Disruption of the rhythm — night-time light exposure, travel across time zones, shift work, mistimed eating, social jet lag — affects GI processes directly: digestion, absorption, **motility**, intestinal barrier function, immune function and the **microbiome**. The paper also discusses circadian-based interventions. Important for the handbook: the article links rhythm disruption to motility and the microbiome — it does NOT claim that sleep deprivation as such accelerates intestinal transit.

[106] Vandeputte D, Falony G, Vieira-Silva S, Tito RY, Joossens M, Raes J. Stool consistency is strongly associated with gut microbiota richness and composition, enterotypes and bacterial growth rates. Gut. 2016. Link

Based on 16S rDNA profiling of faecal samples from 53 healthy women, stool consistency — measured on the Bristol Stool Scale, which reflects faecal **water content** and, through it, colonic transit time — is strongly associated with microbiota **richness**, composition, enterotype and estimated bacterial growth rates. Looser stool was associated with lower richness and a shift towards the Bacteroides enterotype. Important for the handbook: the article links faecal **water content** to the microbiota — it does NOT claim that fluid intake improves engraftment.

[107] Vanhaecke T, Bretin O, Poirel M, Tap J. Drinking Water Source and Intake Are Associated with Distinct Gut Microbiota Signatures in {US. J Nutr. 2022. Link

Using the American Gut Project database (3,413 and 3,794 faecal samples), the authors examined how drinking water **source** and daily **intake** relate to gut and oral microbiota composition, adjusted for anthropometric, dietary and lifestyle factors. Drinking water source ranked among the key factors explaining gut microbiota variation, and both source and amount were associated with distinct microbiota signatures — including differences in the relative abundance of Campylobacter. Important: this is a cross-sectional association, not causal evidence, and not in an FMT population.

[108] Smillie CS, Sauk J, Gevers D, Friedman J, Sung J, Youngster I, Hohmann EL, Staley C, Khoruts A, Sadowsky MJ, Allegretti JR, Smith MB, Xavier RJ, Alm EJ. Strain Tracking Reveals the Determinants of Bacterial Engraftment in the Human Gut Following Fecal Microbiota Transplantation. Cell Host Microbe. 2018. Link

Strain-level tracking after FMT: the authors examined what determines whether a given donor strain engrafts in the recipient. The strongest predictor is the **composition of the recipient's own community** — a strain engrafts when a relative is already present, or when a free ecological niche exists; donor strain richness and strain abundance also matter. Engraftment therefore follows ecological rules rather than chance, and is modifiable from the recipient's side. Important: the paper describes strain-level determinants; it does not prove fibre availability as a modifiable factor in an RCT.

[109] Karl JP, Hatch AM, Arcidiacono SM, Pearce SC, Pantoja-Feliciano IG, Doherty LA, Soares JW. Effects of Psychological, Environmental and Physical Stressors on the Gut Microbiota. Front Microbiol. 2018. Link

Review of how psychological, environmental and physical stressors affect the gut microbiota. The authors argue that various stressors — including sleep deprivation, thermal load, altitude and psychological stress — alter microbiota composition and function through the gut-brain axis and impair intestinal barrier integrity. Important for the handbook: this is a **review**, largely based on animal work and controlled human stress models; it does NOT claim that stress or sleep loss impairs FMT engraftment.

[110] David LA, Maurice CF, Carmody RN, Gootenberg DB, Button JE, Wolfe BE, Ling AV, Devlin AS, Varma Y, Fischbach MA, Biddinger SB, Dutton RJ, Turnbaugh PJ. Diet rapidly and reproducibly alters the human gut microbiome. Nature. 2014. Link

Controlled human intervention study: volunteers consumed an exclusively animal-based, then an exclusively plant-based diet for a short period. Gut microbiota composition and gene expression changed **within 24 hours** and largely reverted after the diet ended. The animal-based diet increased bile-tolerant organisms and decreased strains that ferment plant polysaccharides. This is the classic evidence that the gut flora is a **living system that responds to how we live**, not a static state. Important: short-term, small-sample study, not in an FMT population and not about engraftment.

[111] Koh A, De Vadder F, Kovatcheva-Datchary P, Bäckhed F. From Dietary Fiber to Host Physiology: Short-Chain Fatty Acids as Key Bacterial Metabolites. Cell. 2016. Link

Mechanistic review of short-chain fatty acids (SCFAs), produced by bacterial fermentation of dietary fibre. Fermentable fibre is the primary energy source for the colonic microbiota; the main fermentation products are **acetate, propionate and butyrate**. **Butyrate is the principal energy substrate of colonocytes**; SCFAs also influence barrier integrity, immune function and, once in the circulation, host metabolism, partly via G-protein-coupled receptors (GPR41/43) and histone deacetylase inhibition. This entry is the source for the textbook-level claims of III.2 (S-0302-01, -02). Important: a **review**, not original experimental data.

[112] Shen D, Bai H, Li Z, Yu Y, Zhang H, Chen L. Positive effects of resistant starch supplementation on bowel function in healthy adults: a systematic review and meta-analysis of randomized controlled trials. Int J Food Sci Nutr. 2017. Link

Systematic review and meta-analysis of randomised controlled trials in healthy adults on the effect of resistant starch on large-bowel function. Resistant starch significantly **increased faecal butyrate concentration** (SMD 0.61; 95% CI 0.32-0.89) and faecal wet weight (WMD 35.51 g/d), and significantly **lowered faecal pH** (WMD -0.19); the change in defecation frequency was not significant. Important for the handbook: the meta-analysis establishes that resistant starch is butyrogenic in humans — it does **NOT** examine whether it is more butyrogenic than other prebiotic substrates (no head-to-head comparison), and it was not conducted in an FMT population.

[113] Gibson GR, Roberfroid MB. Dietary modulation of the human colonic microbiota: introducing the concept of prebiotics. J Nutr. 1995. Link

This paper introduced the concept of the **prebiotic**: a non-digestible food ingredient that selectively stimulates the growth or activity of one or a limited number of bacteria in the colon, thereby improving host health. The authors distinguish it from the **probiotic** (which delivers live microorganisms) and the **synbiotic** (a combination of the two), and highlight non-digestible oligosaccharides — including inulin and fructo-oligosaccharides — as examples. This entry is the source for the prebiotic definition in III.2 (S-0302-04). Important: a 1995 conceptual paper; the definition has since been refined several times.

[114] Lozupone CA, Stombaugh JI, Gordon JI, Jansson JK, Knight R. Diversity, stability and resilience of the human gut microbiota. Nature. 2012. Link

Review of the diversity, stability and resilience of the human gut microbiota. Applying ecological concepts to the gut, the authors argue that **species richness and evenness** are key indicators of a community's capacity to withstand perturbation: functional redundancy in a diverse community means the loss of a single taxon is less disruptive. They discuss the concept of dysbiosis and the association of low-diversity states with several diseases. Important: a **review** providing an ecological framework; it does not treat CDI separately and offers no causal evidence.

[115] Cardona F, Andrés-Lacueva C, Tulipani S, Tinahones FJ, Queipo-Ortuño MI. Benefits of polyphenols on gut microbiota and implications in human health. J Nutr Biochem. 2013. Link

Review of the **bidirectional** relationship between polyphenols and the gut microbiota. Most dietary polyphenols are not absorbed in the small intestine but **reach the colon**, where the microbiota metabolises them — and the resulting metabolites are often more biologically active than the parent compounds. Conversely, polyphenols and their derivatives modify microbiota composition in a **prebiotic-like** manner: they can favour Bifidobacterium and Lactobacillus groups and restrain some potential pathogens. The authors also discuss anti-inflammatory and metabolic effects. Important: a **review**, drawing largely on in vitro and small human datasets.

[116] Manach C, Scalbert A, Morand C, Rémésy C, Jiménez L. Polyphenols: food sources and bioavailability. Am J Clin Nutr. 2004. Link

The canonical survey of polyphenol food sources and bioavailability. It catalogues the polyphenol content of several hundred foods and identifies the **richest sources**: berries, cocoa/dark chocolate, tea (including green tea), coffee, red wine, olive oil and certain fruits (including pomegranate). It shows that the relationship between intake and plasma concentration differs greatly between compound classes — the polyphenol consumed in the largest amount is not necessarily the one reaching the highest active concentration. Important: a **nutrition-science review**; effects on the microbiota are not the subject of this paper (see ref-115 for that).

[117] Chung WSF, Walker AW, Louis P, Parkhill J, Vermeiren J, Bosscher D, Duncan SH, Flint HJ. Modulation of the human gut microbiota by dietary fibres occurs at the species level. BMC Biol. 2016. Link

Two structurally distinct non-digestible polysaccharides — **inulin and pectin** — were supplied as energy sources in a controlled fermentation system seeded with human faecal microbiota. The two fibres favoured **different bacterial species**: pectin strongly promoted *Eubacterium eligens*, inulin other groups. The authors conclude that the effect of non-digestible carbohydrates operates at the **species level**, not merely at higher taxonomic ranks. This entry is the source for the III.3 claim that fibre sources of differing carbohydrate structure select different bacterial populations. Important: a controlled fermentation system with human microbiota, not a dietary intervention trial in patients.

[118] Deehan EC, Yang C, Perez-Muñoz ME, Nguyen NK, Cheng CC, Triador L, Zhang Z, Bakal JA, Walter J. Precision Microbiome Modulation with Discrete Dietary Fiber Structures Directs Short-Chain Fatty Acid Production. Cell Host Microbe. 2020. Link

Randomised controlled human trial supplying structurally **distinct corn-starch-based fibres**. The different fibre structures shaped microbiota composition and the resulting **short-chain fatty acid profile differently** — notably the amount of butyrate. The magnitude of response also depended on baseline microbiota composition (individualised response). The authors frame this as *precision microbiome modulation*: choosing the fibre structure can direct the fermentation output. This entry is the source for the III.3 claim that variety supports a broader functional repertoire. Important: healthy adults, not an FMT or CDI population.

[120] Marco ML, Sanders ME, Gänzle M, Arrieta MC, Cotter PD, De Vuyst L, Hill C, Holzapfel W, Lebeer S, Merenstein D, Reid G, Wolfe BE, Hutkins R. The International Scientific Association for Probiotics and Prebiotics ({ISAPP. Nat Rev Gastroenterol Hepatol. 2021. Link

Consensus statement of the ISAPP expert panel. The panel defines fermented foods and beverages as **"foods made through desired microbial growth and enzymatic conversions of food components"**. The definition is explicitly intended to clarify **what is (and is not) a fermented food** — distinguishing, for example, vinegar-pickled (non-fermented) vegetables, and fermented foods that no longer contain live cultures because of heat treatment. The panel separately clarifies the **distinction between fermented foods and probiotics**: probiotics deliver defined strains with documented health effects at a known dose, fermented foods do not necessarily. Safety, risks and nutritional attributes are also addressed. This entry is the source for the definitional claims of III.4.

[121] Savaiano DA, Hutkins RW. Yogurt, cultured fermented milk, and health: a systematic review. Nutr Rev. 2021. Link

A PRISMA-based qualitative systematic review: 108 studies from 1057 screened abstracts, published between 1979 and 2017. Of the 108, 76 reported a favourable health outcome. The authors conclude that **a causal relationship exists between yogurt consumption and lactose digestion and tolerance** — the live cultures in yogurt aid lactose breakdown, so yogurt is well tolerated even by people who do not tolerate milk. Consistent associations with several other health outcomes were also found. Important for the handbook: this entry supports the **tolerability of yogurt** — it does **NOT** examine whether dairy ferments are gentler than plant ferments (no such comparison exists).

[128] Mamerow MM, Mettler JA, English KL, Casperson SL, Arentson-Lantz E, Sheffield-Moore M, Layman DK, Paddon-Jones D. Dietary protein distribution positively influences 24-h muscle protein synthesis in healthy adults. J Nutr. 2014. Link

Randomised crossover study in **healthy adults**: at identical total daily protein intake, an **evenly distributed** pattern (about 30 g protein at breakfast, lunch and dinner) was compared with the usual **evening-skewed** pattern (little in the morning, much at night). 24-hour muscle protein synthesis was **significantly higher** with even distribution. This entry is the source for the III.5 claim that distributing protein across the day — particularly protein at breakfast — is preferable to a single large evening portion. **IMPORTANT LIMITATION:** healthy adults, with muscle protein synthesis as the endpoint; the study was **not** conducted in convalescing gastrointestinal patients and did **not** measure intestinal mucosal regeneration.

[129] Kris-Etherton PM, Harris WS, Appel LJ. Fish consumption, fish oil, omega-3 fatty acids, and cardiovascular disease. Circulation. 2002. Link

American Heart Association scientific statement on fish consumption, fish oil and omega-3 fatty acids. It is the origin of the familiar practical recommendation: **at least two servings of (preferably oily) fish per week**, plus plant-source ALA (flaxseed, walnuts). **IMPORTANT LIMITATION — decisive for the handbook:** this statement concerns **cardiovascular prevention**. It addresses neither intestinal mucosal healing, nor post-FMT convalescence, nor microbiota composition. In III.5 it is therefore used **solely as the source for the practical serving amount**; the mucosal and microbiota effects are sourced to ref-066, ref-093 and ref-065.

[130] Lund, B. M. Microbiological Food Safety for Vulnerable People. Int J Environ Res Public Health. 2015. Link

Review of microbiological food safety for **vulnerable groups** — the immunosuppressed, transplant recipients, cancer patients, pregnant women, older people and young children. The author summarises that in these groups the risk and severity of foodborne infection (Listeria, Salmonella, Campylobacter, E. coli) is **substantially greater**, and that this can be reduced in part through **food choice and handling**: thoroughly cooked meat, pasteurised dairy, avoidance of raw or insufficiently heat-treated foods, and adherence to the cold chain and cross-contamination prevention. This entry is the source for the III.5 claim that raw-material hygiene is especially important in immunosuppressed patients. **LIMITATION:** a review, not an interventional study; not conducted in an FMT or CDI population.

[131] Duncanson KR, Talley NJ, Walker MM, Burrows TL. Food and functional dyspepsia: a systematic review. J Hum Nutr Diet. 2018. Link

Systematic review of which foods and nutrients trigger or worsen the symptoms of functional dyspepsia (FD) — early satiety, post-prandial fullness and epigastric pain. Sixteen of 6451 screened publications met the inclusion criteria. The authors report that a **high-fat diet** is associated with FD symptoms; wheat-containing foods appeared as symptom triggers in six studies. This entry is the source for the III.5 claim that **low-fat, gentle preparation** reduces symptom burden. **IMPORTANT LIMITATION:** the studies were conducted in **adults with functional dyspepsia** — not in patients convalescing after CDI — and did not separately measure the effect of spicing, breading or cooking method. In III.5 it therefore serves as a **guiding analogy, not direct evidence**.

[132] Katz PO, Dunbar KB, Schnoll-Sussman FH, Greer KB, Yadlapati R, Spechler SJ. {ACG. Am J Gastroenterol. 2022. Link

American College of Gastroenterology clinical guideline on the diagnosis and management of gastro-oesophageal reflux disease (GERD). Among the lifestyle recommendations is **avoiding late meals before lying down** — the guideline advises an interval between the last meal and the recumbent position — along with weight reduction and head-of-bed elevation in reflux patients. This entry is the source for the III.6 claim that the last substantial meal should be 2-3 hours before bedtime. **IMPORTANT LIMITATION — decisive for the handbook:** the guideline concerns **reflux**. It addresses neither intestinal regeneration, nor the diurnal rhythm of the microbiota, nor post-FMT convalescence. In III.6 it is therefore used **solely as the source for the timing recommendation**.

[133] Gomes F, Schuetz P, Bounoure L, Austin P, Ballesteros-Pomar M, Cederholm T, Fletcher J, Laviano A, Norman K, Poulia KA, Ravasco P, Schneider SM, Stanga Z, Weekes CE, Bischoff SC. {ESPEN. Clin Nutr. 2018. Link

ESPEN guideline on nutritional support for **polymorbid internal medicine patients** — the population closest to someone convalescing from a protracted infection. The guideline records that in this group **deterioration of nutritional status is common and an independent risk factor**, so intake must be screened and monitored, and **energy and protein targets must be met** rather than intake being restricted. Sustained energy and protein deficit worsens the catabolic state and muscle loss, can impair recovery and may increase complications. This entry is the source for the III.6 claim that **fasting-type protocols are not advisable during convalescence**. Important: the guideline is not about time-restricted eating; it states that in the convalescing polymorbid patient the goal is to SECURE intake.

[134] Bishehsari F, Magno E, Swanson G, Desai V, Voigt RM, Forsyth CB, Keshavarzian A. Alcohol and Gut-Derived Inflammation. Alcohol Res. 2017. Link

Review of how chronic alcohol consumption drives gut-derived inflammation. The authors describe how alcohol **alters gut microbiota composition (dysbiosis)** and **impairs intestinal barrier integrity**, allowing bacterial products (endotoxin) to translocate and producing systemic inflammation; this mechanism links alcohol to liver injury and other organ complications. This entry is the source for the III.7 claim that **alcohol harms the settling flora**. **IMPORTANT LIMITATION:** the paper concerns **chronic alcohol consumption** and covers only the alcohol part of the III.7 statement — it does **not** address the water-secreting effect of sugary drinks or the mild diuretic effect of caffeine. The diuretic effect of alcohol itself is also not from this paper.

[135] Volkert D, Beck AM, Cederholm T, Cruz-Jentoft A, Hooper L, Kiesswetter E, Maggio M, Raynaud-Simon A, Sieber C, Sobotka L, van Asselt D, Wirth R, Bischoff SC. {ESPEN. Clin Nutr. 2022. Link

ESPEN practical guideline on clinical nutrition and **hydration** in older people. The guideline records that **malnutrition and dehydration are widespread in older people** and gives evidence-based recommendations for preventing and treating them. In the hydration section it emphasises that **thirst sensation declines with age**, so fluid intake cannot be left to thirst: it recommends **planned, scheduled drinking**, regular monitoring of intake, and active screening for risk factors and signs of dehydration. This entry is the source for the III.7 claim that planned fluid intake is especially important in older patients. **LIMITATION:** a geriatric guideline; not developed for a CDI or FMT population.

[137] Armstrong LE, Ganio MS, Casa DJ, Lee EC, McDermott BP, Klau JF, Jimenez L, Le Bellego L, Chevillotte E, Lieberman HR. Mild dehydration affects mood in healthy young women. J Nutr. 2012. Link

Randomised crossover study in **25 healthy young women**: mild dehydration of about 1.4% body-mass loss — without heat stress or substantial exertion — **worsened mood**, increased headache symptoms and perceived fatigue, and impaired subjective ratings on tasks requiring concentration. This entry is the source for the III.7 claim that **dehydration worsens wellbeing**. **IMPORTANT LIMITATION — decisive for the handbook:** the study was conducted in **healthy young women** and measured **mood and performance endpoints**. It does **NOT** claim, and did not examine, that dehydration slows **intestinal mucosal regeneration** or makes **engraftment of the new flora** harder.

[138] Bubenik, G. A. Gastrointestinal melatonin: localization, function, and clinical relevance. Dig Dis Sci. 2002. Link

Review of the gastrointestinal (GI) tract's own, extrapineal melatonin. Melatonin concentration in GI tissues exceeds blood levels 10-100 fold, and the gut contains at least 400 times more melatonin than the pineal gland. GI melatonin release is tied to the **periodicity of food intake** rather than to the photoperiod, and it acts locally (endocrine/paracrine/autocrine) to **foster epithelial regeneration**, enhance gut immune function, reduce smooth-muscle tone and protect the mucosa as an antioxidant. This entry is the source for the III.8 clause that melatonin is also present in the GI tract and modulates the mucosa and motility. **LIMITATION:** a review built largely on animal and cell-level data; it does not concern CDI or FMT and does not address melatonin's role as the sleep hormone.

[139] He M, Ru T, Li S, Li Y, Zhou G. Shine light on sleep: Morning bright light improves nocturnal sleep and next morning alertness among college students. J Sleep Res. 2023. Link

Field intervention study on whether morning bright light improves nocturnal sleep. Twelve university students received 1.5 h of bright electric light (1000 lx, 6500 K) versus regular office light (300 lx, 4000 K) on the mornings of one workweek, in a crossover design, measured by actigraphy and sleep diary. Morning bright light produced **higher sleep efficiency** (83.8% vs. 80.4%), a **smaller fragmentation index**, earlier sleep onset, shorter sleep latency and **lower morning sleepiness**. This entry is the source for the III.8 recommendation that morning light after waking stabilises the daily rhythm and eases evening sleep onset. **LIMITATION:** a very small sample (n=12) of healthy university students over a one-week intervention; not a clinical or CDI population.

[140] Edinger JD, Arnedt JT, Bertisch SM, Carney CE, Harrington JJ, Lichstein KL, Sateia MJ, Troxel WM, Zhou ES, Martin JL. Behavioral and psychological treatments for chronic insomnia disorder in adults: an American Academy of Sleep Medicine clinical practice guideline. J Clin Sleep Med. 2021. Link

American Academy of Sleep Medicine (AASM) clinical practice guideline on behavioural and psychological treatments for chronic insomnia disorder in adults, using GRADE methodology. The guideline recommends **multicomponent cognitive behavioural therapy (CBT-I)** as first-line treatment and separately appraises single-component methods, including **stimulus control** (using the bed only for sleep; if sleepiness does not come, get up), **sleep restriction** and relaxation techniques. This entry is the source for the III.8 practical advice that on persistent difficulty falling asleep one should get out of bed and return only when sleepy again. **LIMITATION:** a chronic-insomnia guideline; not CDI- or FMT-specific, and not developed for the transient sleep disturbance during a course of treatment.

[141] Drake C, Roehrs T, Shambroom J, Roth T. Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed. J Clin Sleep Med. 2013. Link

Randomised home-based study of how a fixed caffeine dose given at different times disrupts sleep. The authors gave 400 mg caffeine **0, 3 and 6 hours** before habitual bedtime, versus placebo, with self-reported sleep data and a validated portable sleep monitor. All three timings — even **6 hours before bedtime** — significantly disrupted sleep relative to placebo; based on the reduction in total sleep time, the authors recommend at least 6 caffeine-free hours before bed. This entry is the source for the III.8 caffeine rule. **LIMITATION:** a single fixed dose (400 mg) in healthy sleepers, partly self-reported; the "no caffeine after 2 p.m." rule is a safety margin relative to this, not the paper's direct finding.

[142] Ebrahim IO, Shapiro CM, Williams AJ, Fenwick PB. Alcohol and sleep I: effects on normal sleep. Alcohol Clin Exp Res. 2013. Link

Review of the effect of alcohol on nocturnal sleep based on studies in healthy volunteers. At all doses alcohol **shortens sleep onset latency** and makes the first half of sleep more consolidated, but **increases sleep disruption in the second half of the night**. REM sleep onset is significantly delayed at all doses, and total-night REM proportion falls at moderate and high doses; slow-wave sleep in the first half of the night rises. This entry is the source for the III.8 claim that alcohol — though it makes one drowsy — fragments and shallows nocturnal sleep. **LIMITATION:** a qualitative review in healthy volunteers; not a CDI or FMT population and not about the microbiota.

[143] Schmidt TS, Hayward MR, Coelho LP, Li SS, Costea PI, Voigt AY, Wirbel J, Sunagawa S, Zeller G, Bork P. Extensive transmission of microbes along the gastrointestinal tract. Elife. 2019. Link

Population metagenomic study in 470 individuals from five countries, comparing salivary and faecal strain populations of 310 species. The authors found that **transmission of oral species to, and their colonisation of, the large intestine is common and extensive even in healthy people** — not the rare, disease-marking event previously assumed. A vast majority of oral species are transferable; transmission is higher in colorectal cancer and rheumatoid arthritis and for opportunistic pathogens. This entry is the HUMAN source for the III.8 rationale that the oral cavity is an endogenous reservoir of gut microbial strains, so oral hygiene matters during the course. **LIMITATION:** observational strain tracking; it establishes the reservoir but not that daily toothbrushing changes the CDI or FMT outcome.

[144] Kitamoto S, Nagao-Kitamoto H, Hein R, Schmidt TM, Kamada N. The Intermucosal Connection between the Mouth and Gut in Commensal Pathobiont-Driven Colitis. Cell. 2020. Link

This study describes the intermucosal connection between the mouth and gut in a mouse model: during oral inflammation (periodontitis), oral pathobionts that bloom and are swallowed — including Klebsiella and periodontally primed Th17 cells — translocate to the gut, where they colonise a dysbiotic intestinal environment and aggravate colitis. Two independent axes — microbial (ectopic oral bacteria colonising the gut) and immunological (orally primed T cells migrating to the gut) — jointly link chronic periodontal disease to intestinal inflammation. This entry is the source for the III.8 mechanistic claim that the oral cavity acts as a reservoir of dysbiotic organisms reaching the gut via swallowing. **LIMITATION:** a mouse, mechanistic model; not CDI or FMT and not proof of a human clinical outcome.

[145] Grasa-Ciria D, Couto S, Samatan E, Martinez-Jarreta B, Cenit MDC, Iguacel I. Disrupted Rhythms, Disrupted Microbes: A Systematic Review of Shift Work and Gut Microbiota Alterations. Nutrients. 2025. Link

Systematic review of whether shift work — especially night shift — alters the gut microbiota. The authors searched three databases up to March 2025; five studies were eligible (four small observational and one Mendelian-randomisation). The observational studies reported **reduced alpha-diversity** and increased **pro-inflammatory genera** (Escherichia/Shigella, Blautia, Dialister) in night-shift workers, i.e. shift work is accompanied by dysbiosis. This entry is the source for the III.8 clause that shift work, one form of the host's circadian disruption, is accompanied by disturbance of the microbiota. **LIMITATION:** few, small studies; the compositional difference does not prove causation, and the review is not about a CDI or FMT population.

[146] Oettle, G. J. Effect of moderate exercise on bowel habit. Gut. 1991. Link

Crossover trial in 10 healthy volunteers (6 men, 4 women, aged 22-41): in three one-week periods they ran, cycled, or rested in a chair for 1 hour daily, exercising at two-thirds of predicted maximum heart rate (about 50% VO2max, i.e. moderate/Zone-2 intensity). **Whole-gut transit time was dramatically accelerated** by exercise: 51.2 h at rest, 36.6 h cycling, 34.0 h running (both significantly different from rest, p<0.01); stool weight, defecation frequency, and fibre and fluid intake did not change meaningfully. This entry is the source for the III.9 claim that moderate aerobic movement speeds gut transit. **LIMITATION:** a small, healthy sample; not a CDI or FMT population.

[147] Sorensen L, Larsen KSR, Petersen AK. Validity of the Talk Test as a Method to Estimate Ventilatory Threshold and Guide Exercise Intensity in Cardiac Patients. J Cardiopulm Rehabil Prev. 2020. Link

Validation study in 20 cardiac patients (mean 65 years) examining the relationship between the Talk Test (TT) and the ventilatory threshold (VT) on a cycle ergometer. The TT stages fell within the recommended 40-80% intensity range (58-77%), and heart rate at the equivocal/negative stage did not differ meaningfully from VT — that is, the talk test is a usable group-level intensity guide. This entry is the source for the III.9 claim that being able to sustain continuous speech signals the comfortable (Zone-2) pace. **LIMITATION:** a small sample of cardiac patients; individual precision was poor (wide limits of agreement, correlation 0.37-0.60), so it is a rough compass, not a precise gauge.

[148] Dick NA, Diehl JJ. Febrile illness in the athlete. Sports Health. 2014. Link

Clinical review of the relationship between febrile illness and exercise. The febrile state alters thermoregulation, raises metabolic rate and disturbs fluid homeostasis; human and animal data show that fever-related muscle catabolism reduces muscle strength and endurance. The authors therefore counsel caution with exertion during the febrile phase. This entry is the source for the III.9 claim that the acute, febrile or dehydrated phase is a contraindication to loading, when rest is the priority. **LIMITATION:** an athlete-focused, Level 4 clinical review; there is no strong clinical evidence on the timing of return, and it was not developed for a CDI population.

[149] {American College of Sports Medicine. American College of Sports Medicine position stand. Exercise and fluid replacement. Med Sci Sports Exerc. 2007. Link

American College of Sports Medicine (ACSM) position stand on fluid replacement around exercise. The goal is to be adequately hydrated before activity, to prevent excessive (>2% body-weight loss) dehydration and electrolyte shifts during it, and to replace any fluid and electrolyte deficit afterwards; because of individual variability in sweat rate, customised fluid replacement is recommended. This entry is the source for the III.9 claim that fluid should be replaced both before and after movement. **LIMITATION:** a general exercise/athletic position stand, not CDI- or FMT-specific; the course's fluid-target logic is detailed in III.7 (ref-026).

[150] Holt-Lunstad J, Smith TB, Baker M, Harris T, Stephenson D. Loneliness and Social Isolation as Risk Factors for Mortality: A Meta-Analytic Review. Perspect Psychol Sci. 2015. Link

Meta-analysis of the mortality risk of loneliness, social isolation and living alone. With several confounds statistically controlled, the weighted effect sizes were: social isolation OR = 1.29, loneliness OR = 1.26, living alone OR = 1.32 — a 26–32% increased likelihood of mortality. There was no difference between objective and subjective isolation; results were consistent across gender, follow-up and world region, with social deficits more predictive below age 65. This entry is the source for the III.10 claim that loneliness is an independent health risk and social connection is protective. **LIMITATION:** a meta-analysis of observational studies (association, not causation); not a CDI/FMT population.

[151] Holt-Lunstad J, Smith TB, Layton JB. Social relationships and mortality risk: a meta-analytic review. PLoS Med. 2010. Link

Meta-analysis of 148 studies (308,849 participants) on the association between social relationships and survival. The random-effects weighted average effect size was OR = 1.50 (95% CI 1.42–1.59), a 50% greater likelihood of survival for those with stronger social relationships. The association was consistent across age, sex, initial health status, cause of death and follow-up, and strongest for complex measures of social integration (OR = 1.91). The authors conclude that the influence of social relationships on mortality risk is comparable to well-established risk factors. This entry is the source for the III.10 claim that social connection is an independent, strong health-protective factor. **LIMITATION:** a meta-analysis of observational studies (association); not a CDI/FMT population.

[152] Van Bogart K, Almeida DM, Felt JM, Rush J, Cerino ES, Charles ST. Loneliness, positive social interactions, and diurnal cortisol among mid-to-later life adults in everyday life. Biol Psychol. 2026. Link

Everyday-life (ecological momentary assessment) study in mid-to-later-life adults examining the link between loneliness and diurnal cortisol. Loneliness is a public-health concern linked to stress-related diseases (e.g. cardiovascular); the study found that loneliness experienced in everyday life relates to the dynamic range of diurnal cortisol, and that age and social interactions shape these associations. This entry is the source for the **carefully worded** III.10 claim that loneliness is associated with altered stress-physiological (cortisol) regulation. **LIMITATION:** an observational everyday-life association (not causation, not a simple "elevation"); not a CDI population.

[153] DiMatteo MR, Lepper HS, Croghan TW. Depression is a risk factor for noncompliance with medical treatment: meta-analysis of the effects of anxiety and depression on patient adherence. Arch Intern Med. 2000. Link

Meta-analysis of the association between patient treatment adherence and anxiety/depression; in the included studies the patient was not under psychiatric care but received a somatic regimen recommended by a non-psychiatrist physician. Twelve depression and 13 anxiety articles met inclusion. The anxiety–noncompliance association was variable and on average nonsignificant; the **depression–noncompliance** association, however, was substantial and significant: **OR = 3.03** (95% CI 1.96–4.89) — the odds of noncompliance are 3 times greater in depressed patients. This entry is the source for the III.10 claim that a psyche worsening during illness (depression in particular) impairs treatment adherence. **LIMITATION:** a meta-analysis spanning mixed somatic conditions; not specifically CDI, and it measures association.

[154] Tariq R, Singh S, Gupta A, Pardi DS, Khanna S. Association of Gastric Acid Suppression With Recurrent Clostridium difficile Infection: A Systematic Review and Meta-analysis. JAMA Intern Med. 2017. Link

Systematic review and meta-analysis of whether gastric acid suppression (mainly PPIs, and H2 blockers) is associated with the risk of **recurrent** *Clostridioides difficile* infection. Five databases were searched from 1995–2015; case-control, cohort and clinical studies were included in which CDI patients did or did not receive gastric acid suppression and recurrence was assessed. Gastric acid suppression was associated with significantly higher odds of recurrent CDI (pooled OR about 1.5). This entry is the source for the III.11 claim that long-term PPI use carries an elevated risk of recurrent CDI. **LIMITATION:** a meta-analysis of observational studies — association, not causation; the authors themselves caution about residual confounding (PPI users are often sicker/older), so unsupervised discontinuation is not warranted, only clinical review.

[155] Langdon A, Schwartz DJ, Bulow C, Sun X, Hink T, Reske KA, Dubberke ER, Dantas G. Microbiota restoration reduces antibiotic-resistant bacteria gut colonization in patients with recurrent Clostridioides difficile infection from the open-label PUNCH CD study. Genome Med. 2021. Link

Secondary analysis of an open-label clinical trial (PUNCH CD): faecal samples from 29 recurrent-CDI patients were analysed before and up to six months after administration of the microbiota-based product RBX2660, by 16S sequencing, whole-metagenome shotgun sequencing (resistome content) and selective culture. Successful prevention of CDI recurrence correlated with taxonomic convergence of patient microbiota toward the donor; RBX2660 **dramatically reduced the abundance of antibiotic-resistant Enterobacteriaceae** in the 2 months after administration, and **faecal antibiotic resistance gene (resistome) carriage decreased in direct relationship to the degree to which the donor microbiota engrafted**. This entry is the source for the IV.1 claim that donor-microbiota engraftment and resistome restoration dynamics are linked. **LIMITATION:** open-label, small sample (n=29), and the product studied is **RBX2660** (not DiffBiome) — the mechanism concerns rCDI microbiota therapy, not product-specific evidence.

[156] Ianiro G, Puncochar M, Karcher N, Porcari S, Armanini F, Asnicar F, Segata N. Variability of strain engraftment and predictability of microbiome composition after fecal microbiota transplantation across different diseases. Nat Med. 2022. Link

Integrated shotgun-metagenomic meta-analysis of 226 triads (donor, pre-FMT and post-FMT recipient) across eight different disease types, using improved strain profiling. The key finding: **recipients with higher donor-strain engraftment were more likely to achieve clinical success** after FMT (P=0.017). Engraftment depends on the donor, the delivery route (multi-route — e.g. capsule plus colonoscopy together — gives higher engraftment) and the recipient (higher in antibiotic-treated infectious-disease recipients than in antibiotic-naive noncommunicable-disease patients); Bacteroidetes and Actinobacteria species engraft better. This entry is the source for the IV.3 claim that, because of donor-dependent engraftment variability, an alternative donor lot (LOT switch) can improve the outcome. **LIMITATION:** an observational meta-analysis across eight disease types (not CDI alone), measuring association; it did not study product-LOT switching as such.

[157] Sheitoyan-Pesant C, Abou Chakra CN, Pepin J, Marcil-Heguy A, Nault V, Valiquette L. Clinical and Healthcare Burden of Multiple Recurrences of Clostridium difficile Infection. Clin Infect Dis. 2016. Link

Retrospective cohort of adults diagnosed with CDI at a hospital in Sherbrooke, Canada (1998–2013), assessing the burden of multiple recurrences. 1527 patients. The **probability of a first recurrence was 25%** (354/1418), of a **second 38%** (128/334), a third 29% (35/121), and a fourth or more 27% (9/33); two or more recurrences occurred in 9% of patients. The severity and complication risk of recurrences decreased with successive episodes. This entry is the source for the IV.4 claim that CDI recurrence risk is significant and rises with each further recurrence. **LIMITATION:** a single-centre retrospective cohort; the per-episode conditional probabilities (25%, 38%) are lower than the commonly cited cumulative ">60%" guideline estimate — which is why the handbook uses the specific cohort figures.

[158] Cruz-Jentoft AlfonsoJ, Bahat Gülistan, Bauer Jürgen, Boirie Yves, Bruyère Olivier, Cederholm Tommy, Cooper Cyrus, Landi Francesco, Rolland Yves, Sayer AvanAihie, Schneider StéphaneM, Sieber CornelC, Topinková Eva, Vandewoude Maurits, Visser Marjolein, Zamboni Mauro. Sarcopenia: revised {European. Age and Ageing. 2019. Link

In 2010 the European Working Group on Sarcopenia in Older People (EWGSOP) issued a definition of sarcopenia; in 2018 the group reconvened (EWGSOP2) to update it in light of a decade of new evidence, and this paper presents the revised consensus. EWGSOP2 reframes sarcopenia as a progressive muscle disease (muscle failure) and now places low muscle strength at the centre of the diagnosis, using low muscle quantity or quality to confirm it and poor physical performance to indicate severe sarcopenia. The paper provides an updated case-finding, diagnosis and severity algorithm together with clear cut-off points for the measured variables. The authors call on clinicians to detect and treat sarcopenia early to prevent adverse outcomes that burden patients and health systems.

[159] Volkert D, Beck AM, Cederholm T, Cruz-Jentoft A, Goisser S, Hooper L, Kiesswetter E, Maggio M, Raynaud-Simon A, Sieber CC, Sobotka L, van Asselt D, Wirth R, Bischoff SC. {ESPEN. Clinical Nutrition. 2019. Link

Malnutrition and dehydration are widespread among older people, while obesity is a growing problem. This ESPEN guideline provides evidence-based recommendations for clinical nutrition and hydration in older persons in order to prevent and treat malnutrition and dehydration. It also addresses whether — and when — weight-reducing interventions are appropriate in overweight or obese older adults. The practical message is to screen nutritional and hydration status routinely and to apply individualised interventions aimed at preserving function, mobility and quality of life.

[160] Hocquart M, Lagier JC, Cassir N, Saidani N, Eldin C, Kerbaj J, Delord M, Valles C, Brouqui P, Raoult D, Million M. Early Fecal Microbiota Transplantation Improves Survival in Severe Clostridium difficile Infections. Clin Infect Dis. 2018. Link

Retrospective cohort study (Marseille, North University Hospital, 2013–2016) of whether **early FMT** improves survival in hospitalised CDI patients, particularly in severe infection. 111 patients: 66 FMT, 45 non-FMT. The primary endpoint was **3-month mortality**. Independent predictors: O27 ribotype (OR 3.64), severe CDI (OR 9.62) and FMT (OR 0.13 — protective). FMT reduced mortality **in severe cases** (OR 0.08; NNT = 2 to save one life at 3 months) but **not in non-severe** cases (OR 1.07). The authors conclude early FMT should be considered first-line for severe CDI. **LIMITATION:** single-centre retrospective cohort; no surgical patients; the effect appeared only in the severe subgroup — hence this is a hospital, not a home, decision, which the handbook stresses.

[161] Dimidi E, Cox SR, Rossi M, Whelan K. Fermented Foods: Definitions and Characteristics, Impact on the Gut Microbiota and Effects on Gastrointestinal Health and Disease. Nutrients. 2019. Link

Review defining fermented foods as products of controlled microbial growth and enzymatic substrate conversion, characterizing common items (kefir, kombucha, sauerkraut, tempeh, natto, miso, kimchi, sourdough bread) and their proposed mechanisms — including microbiota effects. The review summarizes evidence for fermented-food impact on human gastrointestinal health and disease, supporting selective incorporation into health-promoting dietary patterns.

[238] Chassaing B, Compher C, Bonhomme B et al. Randomized Controlled-Feeding Study of Dietary Emulsifier Carboxymethylcellulose Reveals Detrimental Impacts on the Gut Microbiota and Metabolome. Gastroenterology. 2022. Link

16-subject controlled-feeding RCT in human volunteers. Diet containing carboxymethylcellulose (CMC, E466) emulsifier altered gut microbiota composition within 11 days, decreased microbial diversity and fermentation metabolite levels, and two participants showed signs of bacterial encroachment into the mucus layer. First human evidence that CMC at approved daily exposure levels has detrimental microbiological effects.

[445] Cryan JF, O'Riordan KJ, Cowan CSM et al. The Microbiota-Gut-Brain Axis. Physiol Rev. 2019. Link

A comprehensive review (Cryan et al., Physiol Rev 2019) of the microbiota-gut-brain axis. It details the communication routes linking the gut microbiota and the brain, including the immune system, tryptophan metabolism, the vagus nerve and enteric nervous system, and microbial metabolites (short-chain fatty acids, branched-chain amino acids, peptidoglycans). The article surveys animal and human evidence for the axis's physiological and behavioral/neurological significance.

[447] Peery AF, Kelly CR, Kao D et al. AGA Clinical Practice Guideline on Fecal Microbiota-Based Therapies for Select Gastrointestinal Diseases. Gastroenterology. 2024. Link

AGA clinical practice guideline using the GRADE framework to address fecal microbiota-based therapies (conventional FMT, fecal microbiota live-jslm, fecal microbiota spores live-brpk) in adults with recurrent or severe-to-fulminant Clostridioides difficile infection, IBD/pouchitis, and IBS. The panel issued 7 recommendations. In immunocompetent adults with recurrent CDI, the AGA suggests selective use of fecal microbiota-based therapies after standard-of-care antibiotics to prevent further recurrence. Provides framework guidance integrating FDA-approved products with conventional FMT.

[454] Gogokhia L, Tran N, Grier A, Nagayama M, Xiang G, Funez-dePagnier G, Lavergne A, Ericsson C, Ben Maamar S, Zhang M, Battat R, Scherl E, Lukin DJ, Longman RS. Donor composition and fiber promote strain engraftment in a randomized controlled trial of fecal microbiota transplant for ulcerative colitis. Med. 2025. Link

The MINDFUL randomized, double-blind, placebo-controlled trial assigned 27 patients with mild-to-moderate ulcerative colitis to a single FMT or placebo, with or without psyllium fibre supplementation, over 8 weeks. FMT induced clinical response, remission and endoscopic improvement versus placebo (p < 0.05). Fibre supplementation did not improve clinical outcomes, but strain-level metagenomic analysis showed that donor community composition together with recipient fibre intake shaped donor-strain engraftment. This is among the first randomized human evidence that post-procedure dietary (exposome) factors directly influence FMT engraftment, while showing that improved engraftment does not automatically translate into better clinical outcomes. ClinicalTrials.gov: NCT03998488.

[483] Baxter NT, Schmidt AW, Venkataraman A, Kim KS, Martens EC, Schloss PD. Dynamics of Human Gut Microbiota and Short-Chain Fatty Acids in Response to Dietary Interventions with Three Fermentable Fibers. mBio. 2019. Link

Two-week dietary intervention in 174 healthy young adults supplementing with resistant starch from potatoes (RPS), resistant starch from maize (RMS), inulin, or accessible corn-starch control. RPS produced the greatest increase in total SCFAs including butyrate. Most microbiomes responded to RPS with increased bifidobacteria, but responders with rising Ruminococcus bromii or Clostridium chartatabidum showed the highest butyrate concentrations. The study demonstrates substrate- and taxon-specific routes to butyrate enrichment, informing personalized prebiotic strategies.

[487] Khoruts A, Sadowsky MJ. Understanding the mechanisms of faecal microbiota transplantation. Nat Rev Gastroenterol Hepatol. 2016. Link

Mechanistic review of FMT in recurrent C. difficile infection summarizing the proposed mechanisms of action: direct competition between C. difficile and commensals introduced by FMT, restoration of secondary bile acid metabolism (which inhibits C. difficile germination), and repair of the gut barrier through mucosal immune stimulation. The review consolidates the mechanistic basis for FMT in CDI and highlights translational implications for engineered microbial therapeutics targeting these pathways.

[525] Dueñas M, Muñoz-González I, Cueva C et al. A survey of modulation of gut microbiota by dietary polyphenols. Biomed Res Int. 2015. Link

Review of polyphenol modulation of gut microbiota by experimental design type: batch cultures, gastrointestinal simulators, animal models, and human intervention studies. Evidence converges on consistent polyphenol-driven shifts toward beneficial taxa (Bifidobacterium, Lactobacillus) and on microbiota-dependent generation of bioactive polyphenol metabolites. The review provides a structured synthesis of the polyphenol–microbiota field to support translational research and dietary recommendations.

[610] Jernberg C, Löfmark S, Edlund C, Jansson JK. Long-term ecological impacts of antibiotic administration on the human intestinal microbiota. ISME J. 2007. Link

This 2-year longitudinal study tracked the faecal microbiota of four healthy subjects exposed to 7-day clindamycin therapy and four controls at nine time points. Polyphasic analysis showed highly significant disturbances persisting for the entire follow-up. Clonal diversity of Bacteroides isolates declined sharply by rep-PCR, with long-term persistence of highly resistant clones. The Bacteroides community never returned to its original composition by T-RFLP fingerprinting. The findings document multi-year ecological consequences of a single short course of clindamycin.

[667] Sanidad KZ, Xiao H, Zhang G, et al. Triclosan has a robust, yet reversible impact on human gut microbial composition in vitro. . 2020. Link

In an in vitro human gut microbiome model, triclosan robustly altered the microbial community: it reduced population size, diversity and metabolite production, selectively suppressing certain commensal taxa. The effect was largely reversible after a two-week recovery period. The study provides direct mechanistic evidence for triclosan's microbiota-disrupting effect; triclosan's antibiotic-resistance-selecting potential is supported by separate exposure (mouse and environmental) studies.

[735] Cammarota G, Ianiro G, Kelly CR et al. International consensus conference on stool banking for faecal microbiota transplantation in clinical practice. Gut. 2019. Link

This international consensus from FMT experts in Europe, North America and Australia provides statements on stool banking for FMT, covering general principles, organization, donor selection and screening, stool collection/preparation/storage, services and clients, registries, outcome monitoring, ethics and FMT's evolving clinical role. Consensus was achieved through Delphi rounds plus plenary discussion, with statements supported by best available evidence. The document guides global stool-bank development to promote safe, equitable FMT access for recurrent C. difficile infection.

[777] Mullish BH, Merrick B, Quraishi MN et al. The use of faecal microbiota transplant as treatment for recurrent or refractory Clostridioides difficile infection and other potential indications: second edition of joint British Society of Gastroenterology (BSG) and Healthcare Infection Society (HIS) guidelines. Gut. 2024. Link

The 2024 second edition of the joint British Society of Gastroenterology (BSG) and Healthcare Infection Society (HIS) guidelines on faecal microbiota transplant (FMT) for recurrent or refractory Clostridioides difficile infection and other potential indications. It updates the 2018 first edition with evidence from national FMT registries. It also sets out the UK regulatory framework: the MHRA treats FMT as a medicinal product for human use, centres processing and distributing FMT must obtain MHRA licences, and a pharmacy exemption may apply when FMT is supplied on a named-patient basis within a single organisation. Detailed recommendations cover donor screening, product manufacture, delivery routes and patient follow-up.

[832] Reygner J, Charrueau C, Delannoy J, Mayeur C, Robert V, Cuinat C, Meylheuc T, Mauras A, Augustin J, Nicolis I, Modoux M, Joly F, Waligora-Dupriet A, Thomas M, Kapel N. Freeze-dried fecal samples are biologically active after long-lasting storage and suited to fecal microbiota transplantation in a preclinical murine model of. Gut microbes. 2020. Link

Lyophilized FMT inocula can be stored for 12 months with stable viability; oral hard-capsule formulation is feasible with 0.5% glidant excipient — Lyophilized and frozen FMT samples retain viability, SCFA concentrations, and anti-C. difficile activity after 12 months of storage. The lyophilized powder can be filled into oral hard capsules; in a murine model, 70% survival rate (vs. 53–60% frozen, 20% untreated). Supports the feasibility of oral capsule formulation.

[833] Zain N, Merrick B, Martin-Lilley T, Edwards L, Ter Linden D, Tsoka S, Mason A, Hatton G, Allen E, Royall P, Lilley A, Bruce K, Shawcross D, Goldenberg S, Forbes B. Bacterial diversity, viability and stability in lyophilised faecal microbiota capsules support ongoing clinical use. International journal of pharmaceutics. 2025. Link

Bacterial diversity and viability of lyophilized enteric-coated FMT capsules are stable at −80°C for 36 weeks, at −20°C and 2–8°C for 24 weeks — supporting cold-chain-flexible clinical application — Lyophilized FMT capsules manufactured under King's College London GMP protocol (5 donors, 16S rRNA sequencing + live-dead separation): species diversity remained stable after manufacturing and 36 weeks of storage at −80°C. No significant viability loss at −20°C and 2–8°C for 24 weeks. Anaerobes survive aerobic processing with minimal loss. Confirms clinical applicability of the lyophilized capsule form with efficacy comparable to other formulations.

Note: the items above provide the book's external, citable evidence base. The internal, MicroBiome Bank source documents (DiffBiome / HospBiome Service Datasheet, SIS Clinical Guide, Clinical protocol guide v7.1, capsule density protocol, DSQ cards, C. diff clearance strategy 2026) supply the product- and protocol-specific facts; these are not public literature items but the provider's own, referenced documents.