fecal bacteriotherapy

Overview

Fecal bacteriotherapy, more commonly known as fecal microbiota transplantation (FMT), is a therapeutic procedure in which fecal material containing a complex community of microorganisms is transferred from a healthy donor into the gastrointestinal tract of a recipient. The procedure aims to restore a disrupted or dysbiotic gut microbiome by introducing a diverse, balanced microbial ecosystem. The human gut flora plays a central role in metabolic regulation, immune modulation, and neurological signaling, and its disruption has been implicated in a growing number of conditions ranging from gastrointestinal diseases to neurodevelopmental and neuropsychiatric disorders. FMT works by re-seeding the gut with beneficial bacterial taxa, displacing pathogenic or imbalanced microbial communities, and re-establishing homeostatic microbiota-metabolite interaction networks that influence host physiology.

Beyond its established use in recurrent Clostridioides difficile infection, FMT has attracted substantial scientific interest as a modulator of systemic disease. The procedure operates through multiple mechanistic axes, including the production of short-chain fatty acids, neurotransmitter precursors such as dopamine, and bioactive Metabolites that traverse the gut-blood-brain barrier. Its capacity to recapitulate donor phenotypes in recipients — including behavioral, metabolic, and immunological traits — has made it an essential experimental tool for establishing causal relationships between gut microbiota composition and disease states.

Focus of Latest Publications

Recent literature has positioned FMT at the intersection of oncology, neuroscience, metabolic medicine, and psychiatry, reflecting the broad systemic influence of the gut microbiome.

Oncology and immunotherapy A 2026 review in Oncoimmunology highlighted FMT alongside probiotic supplementation and dietary modulation as promising strategies to reshape the tumor microenvironment and enhance responses to checkpoint inhibitor-based immunotherapy in urothelial carcinoma. Modulating the gut microbiome through FMT is hypothesized to promote dendritic cell activation and T-lymphocyte infiltration into tumors, potentiating anti-tumor immune responses. A phase I feasibility and safety study published in the Journal for immunotherapy of Cancer evaluated FMT combined with anti-PD-1 therapy in patients with refractory microsatellite-stable gastric cancer — a tumor subtype historically resistant to immunotherapy — finding the combination to be feasible and warranting further investigation.

Neuropsychiatric and Neurodegenerative Conditions A randomized, double-blind, placebo-controlled phase 2 trial published in Signal Transduction and Targeted Therapy assessed repeated donor FMT (dFMT) in drug-naïve Parkinson's disease patients. The trial reported improvements in both motor and gastrointestinal symptoms, establishing clinical proof of concept for gut microbiome modulation in early-stage Parkinson's disease. A complementary preclinical study in Neurochemical Research demonstrated that FMT from exercise-preconditioned mice attenuated post-stroke cognitive impairment in recipient animals by preserving integrity of the gut and blood-brain barrier, underscoring the gut-brain axis as a mediable therapeutic target.

In the context of antipsychotic-induced side effects, a Cell Host & Microbe study found that FMT from olanzapine-treated mice conferred synaptic and cognitive impairments in recipient animals, implicating gut microbiota as a mediator of antipsychotic toxicity; ergothioneine supplementation was found to mitigate these effects. A separate Cell Host & Microbe publication demonstrated that FMT from liraglutide-treated mice, or colonization with Lactobacillus delbrueckii, replicated antidepressant effects in recipients, establishing that the antidepressant action of this GLP-1 analog — known to signal through GLP1R — is in part mediated through microbiota-driven gut-brain signaling.

Autism Spectrum Disorder A Journal of Translational Medicine study employed multi-matrix metabolomics to characterize fecal and urinary metabolic signatures in autism spectrum disorder (ASD) and evaluate the longitudinal metabolic remodeling effects of FMT. The study mapped microbiota-metabolite interaction networks to identify mechanisms by which gut dysbiosis may contribute to ASD pathophysiology, and demonstrated that FMT induced systemic metabolic shifts consistent with therapeutic remodeling.

Metabolic Disease and obesity A PLOS One study investigated FMT from exercise-conditioned and inulin-supplemented donor mice in obese mice, finding that a continuous high-fat, high-sugar diet in recipients overrode the therapeutic potential of FMT, even when donors had undergone beneficial lifestyle and dietary conditioning. This finding highlights the critical importance of recipient dietary context in determining FMT efficacy for obesity and metabolic disorders.

artificial intelligence-Assisted Donor Matching Acknowledging that clinical FMT efficacy remains individually variable, a Cell Reports study introduced the Mozaic platform — an AI-driven framework for donor-recipient gut microbiome matching — as a strategy to optimize FMT outcomes by pairing recipients with the most compatible donors based on microbiome composition.

Key Publications

• Jun Adjunctive fecal microbiota transplantation for major depressive disorder: A randomized, double-blind, placebo-controlled trial. (Cell host & microbe, 2026, PMID 42309058): "administering a 2-week course of fecal microbiota transplantation (FMT) capsules or placebo as an adjunct to escitalopram (ChiCTR2300071421)."
• Jun A fructan-type polysaccharide from Lycium ruthenicum attenuates liver fibrosis via microbiota-dependent ferroptosis inhibition. (Carbohydrate polymers, 2026, PMID 42002330): "Crucially, antibiotic depletion abolished LRMP1's efficacy, whereas fecal microbiota transplantation and fermentation supernatant experiments confirmed that microbiota-derived postbiotics selectively protect hepatocytes from ferroptosis."
• Jun Food-grade TiO2 impairs intestinal mucus barrier via disrupting the gut microbiota-ILA-mucin sulfation axis: novel insights and dietary intervention strategies. (Journal of nanobiotechnology, 2026, PMID 42289709): "Notably, experiments involving fecal microbiota transplantation (FMT) and ILA supplementation indicated gut microbial shifts and the consequent decrease in colonic ILA levels were accountable for the detrimental effects of fg-TiO2 on mucin sulfation and intestinal barrier integrity."
• Jun Microbiota-driven gut-brain signaling underlies antidepressant effects of a GLP-1 analog. (Cell host & microbe, 2026, PMID 42269582): "Importantly, fecal microbiota transplantation from liraglutide-treated mice or Lactobacillus delbrueckii colonization replicated the antidepressant effects."
• May Artificial intelligence-driven donor-recipient gut microbiome matching for optimized fecal microbiota transplantation. (Cell reports, 2026, PMID 42061404): "Fecal microbiota transplantation (FMT) has emerged as a promising therapy for gastrointestinal diseases, yet its clinical efficacy remains individually variable."
• May Fecal Microbiota Transplantation from Exercise-Preconditioned Mice Attenuates Post-stroke Cognitive Impairment by Preserving Gut and Blood-Brain Barrier Integrity. (Neurochemical research, 2026, PMID 42171840): "Then, we used fecal microbiota transplantation (FMT) to evaluate how GM contributes to the benefits of voluntary exercise."
• May Integrated multi-matrix metabolomics reveals gut microbiota-driven systemic metabolic alterations and therapeutic remodeling by fecal microbiota transplantation in autism spectrum disorder. (Journal of translational medicine, 2026, PMID 42157185): "Specifically, this study aims to address three core objectives: (1) to characterize the paired fecal and urinary metabolic signatures of ASD; (2) to map the microbiota-metabolite interaction networks; and (3) to evaluate the longitudinal metabolic remodeling effects of FMT."
• May Gut microbiota-derived ergothioneine alleviates antipsychotic-induced synaptic and cognitive impairments. (Cell host & microbe, 2026, PMID 42013837): "Fecal microbiota transplantation from olanzapine-treated mice confers cognitive impairment, while ergothioneine supplementation mitigates it."
• May Continuous high-fat high-sugar diet overrides the therapeutic potential of fecal microbiota transplantation from exercised and/or inulin-conditioned donors in obese mice. (PloS one, 2026, PMID 42118793): "Fecal microbiota transplantation (FMT) is a promising therapeutic strategy for obesity and related metabolic disorders."
• Apr Killing cancer takes guts: lessons learned from the manipulation of gut microbiome and immunotherapy for the future of urothelial carcinoma. (Oncoimmunology, 2026, PMID 41560593): "Fecal microbiota transplantation (FMT), probiotic supplementation, and dietary modulation have emerged as promising methods to alter microbiomes to improve immunotherapy outcomes."