The effect of fecal microbiota transplantation on antibiotic-associated diarrhea and its impact on gut microbiota.

BACKGROUND: Antibiotic-associated diarrhea (AAD) refers to symptoms of diarrhea that cannot be explained by other causes after the use of antibiotics. AAD is thought to be caused by a disruption of intestinal ecology due to antibiotics. Fecal Microbiota Transplantation (FMT) is a treatment method that involves transferring microbial communities from the feces of healthy individuals into the patient's gut. METHOD: We selected 23 AAD patients who received FMT treatment in our department. Before FMT, we documented patients' bowel movement frequency, abdominal symptoms, routine blood tests, and inflammatory markers, and collected fecal samples for 16S rRNA sequencing to observe changes in the intestinal microbiota. Patients' treatment outcomes were followed up 1 month and 3 months after FMT. RESULTS: Out of the 23 AAD patients, 19 showed a clinical response to FMT with alleviation of abdominal symptoms. Among them, 82.61% (19/23) experienced relief from diarrhea, 65% (13/20) from abdominal pain, 77.78% (14/18) from abdominal distension, and 57.14% (4/7) from bloody stools within 1 month after FMT. Inflammatory markers IL-8 and CRP significantly decreased after FMT, but there were no noticeable changes in WBC, IL-6, and TNF-α before and after transplantation. After FMT, the abundance of Bacteroides and Faecalibacterium increased in patients' fecal samples, while the abundance of Escherichia-Shigella and Veillonella decreased. CONCLUSION: FMT has a certain therapeutic effect on AAD, and can alleviate abdominal symptoms and change the intestinal microbiota of patients.

Fecal microbiota transplantation for irritable bowel syndrome: Current evidence and perspectives.

In this editorial we comment on the article published in the recent issue of the World journal of Gastroenterology. We focus specifically on the mechanisms un-derlying the effects of fecal microbiota transplantation (FMT) for irritable bowel syndrome (IBS), the factors which affect the outcomes of FMT in IBS patients, and challenges. FMT has emerged as a efficacious intervention for clostridium difficile infection and holds promise as a therapeutic modality for IBS. The utilization of FMT in the treatment of IBS has undergone scrutiny in numerous randomized controlled trials, yielding divergent outcomes. The current frontier in this field seeks to elucidate these variations, underscore the existing knowledge gaps that necessitate exploration, and provide a guideline for successful FMT imple-mentation in IBS patients. At the same time, the application of FMT as a treatment for IBS confronts several challenges.

Mechanisms of microbiota modulation: Implications for health, disease, and therapeutic interventions.

Microbiota modulation, the intentional change in the structure and function of the microbial community, is an emerging trajectory that holds the promise to mitigate an infinite number of health issues. The present review illustrates the underlying principles of microbiota modulation and the various applications of this fundamental process to human health, healthcare management, and pharmacologic interventions. Different strategies, directing on dietary interventions, fecal microbiota transplantation, treatment with antibiotics, bacteriophages, microbiome engineering, and modulation of the immune system, are described in detail. This therapeutic implication is reflected in clinical applications to gastrointestinal disorders and immune-mediated diseases for microbiota-modulating agents. In addition to this, the review outlines the challenges of translating researched outcomes into clinical practice to consider safety and provides insights into future research directions of this rapidly developing area.

Rejuvenating fecal microbiota transplant enhances peripheral nerve repair in aged mice by modulating endoneurial inflammation.

Peripheral nerve injury (PNI) resulting from trauma or neuropathies can cause significant disability, and its prognosis deteriorates with age. Emerging evidence suggests that gut dysbiosis and reduced fecal short-chain fatty acids (SCFAs) contribute to an age-related systemic hyperinflammation (inflammaging), which hinders nerve recovery after injury. This study thus aimed to evaluate the pro-regenerative effects of a rejuvenating fecal microbiota transplant (FMT) in a preclinical PNI model using aged mice. Aged C57BL/6 mice underwent bilateral crush injuries to their sciatic nerves. Subsequently, they either received FMT from young donors at three and four days after the injury or retained their aged gut microbiota. We analyzed gut microbiome composition and SCFA concentrations in fecal samples. The integrity of the ileac mucosal barrier was assessed by immunofluorescence staining of Claudin-1. Flow cytometry was utilized to examine immune cells and cytokine production in the ileum, spleen, and sciatic nerve. Various assessments, including behavioural tests, electrophysiological studies, and morphometrical analyses, were conducted to evaluate peripheral nerve function and repair following injury. Rejuvenating FMT reversed age-related gut dysbiosis by increasing Actinobacteria, especially Bifidobacteriales genera. This intervention also led to an elevation of gut SCFA levels and mitigated age-related ileac mucosal leakiness in aged recipients. Additionally, it augmented the number of T-helper 2 (Th2) and regulatory T (Treg) cells in the ileum and spleen, with the majority being positive for anti-inflammatory interleukin-10 (IL-10). In sciatic nerves, rejuvenating FMT resulted in increased M2 macrophage counts and a higher IL-10 production by IL-10+TNF-α- M2 macrophage subsets. Ultimately, restoring a youthful gut microbiome in aged mice led to improved nerve repair and enhanced functional recovery after PNI. Considering that FMT is already a clinically available technique, exploring novel translational strategies targeting the gut microbiome to enhance nerve repair in the elderly seems promising and warrants further evaluation.

Effects of microbiome-based interventions on neurodegenerative diseases: a systematic review and meta-analysis.

Neurodegenerative diseases (NDDs) are characterized by neuronal damage and progressive loss of neuron function. Microbiome-based interventions, such as dietary interventions, biotics, and fecal microbiome transplant, have been proposed as a novel approach to managing symptoms and modulating disease progression. Emerging clinical trials have investigated the efficacy of interventions modulating the GM in alleviating or reversing disease progression, yet no comprehensive synthesis have been done. A systematic review of the literature was therefore conducted to investigate the efficacy of microbiome-modulating methods. The search yielded 4051 articles, with 15 clinical trials included. The overall risk of bias was moderate in most studies. Most microbiome-modulating interventions changed the GM composition. Despite inconsistent changes in GM composition, the meta-analysis showed that microbiome-modulating interventions improved disease burden (SMD, - 0.57; 95% CI - 0.93 to - 0.21; I2 = 42%; P = 0.002) with a qualitative trend of improvement in constipation. However, current studies have high methodological heterogeneity and small sample sizes, requiring more well-designed and controlled studies to elucidate the complex linkage between microbiome, microbiome-modulating interventions, and NDDs.

Advances in fecal microbiota transplantation for the treatment of diabetes mellitus.

Diabetes mellitus (DM) refers to a group of chronic diseases with global prevalence, characterized by persistent hyperglycemia resulting from various etiologies. DM can harm various organ systems and lead to acute or chronic complications, which severely endanger human well-being. Traditional treatment mainly involves controlling blood sugar levels through replacement therapy with drugs and insulin; however, some patients still find a satisfactory curative effect difficult to achieve. Extensive research has demonstrated a close correlation between enteric dysbacteriosis and the pathogenesis of various types of DM, paving the way for novel therapeutic approaches targeting the gut microbiota to manage DM. Fecal microbiota transplantation (FMT), a method for re-establishing the intestinal microbiome balance, offers new possibilities for treating diabetes. This article provides a comprehensive review of the correlation between DM and the gut microbiota, as well as the current advancements in FMT treatment for DM, using FMT as an illustrative example. This study aims to offer novel perspectives and establish a theoretical foundation for the clinical diagnosis and management of DM.

The Many Faces of Metabolic Dysfunction-Associated Fatty Liver Disease Treatment: From the Mediterranean Diet to Fecal Microbiota Transplantation.

The gastrointestinal tract is inhabited by the gut microbiota. The main phyla are Firmicutes and Bacteroidetes. In non-alcoholic fatty liver disease, now renamed metabolic dysfunction-associated fatty liver disease (MAFLD), an alteration in Firmicutes and Bacteroidetes abundance promotes its pathogenesis and evolution into non-alcoholic steatohepatitis, liver cirrhosis, and hepatocellular carcinoma. For this reason, early treatment is necessary to counteract its progression. The aim of the present narrative review is to evaluate the different therapeutic approaches to MAFLD. The most important treatment for MAFLD is lifestyle changes. In this regard, the Mediterranean diet could be considered the gold standard in the prevention and treatment of MAFLD. In contrast, a Western diet should be discouraged. Probiotics and fecal microbiota transplantation seem to be valid, safe, and effective alternatives for MAFLD treatment. However, more studies with a longer follow-up and with a larger cohort of patients are needed to underline the more effective approaches to contrasting MAFLD.

Third-party fecal microbiota transplantation for high-risk treatment-naïve acute GVHD of the lower GI tract.

ABSTRACT: Disruption of the intestinal microbiome is observed with acute graft-versus-host disease (GVHD) of the lower gastrointestinal (LGI) tract, and fecal microbiota transplantation (FMT) has successfully cured steroid-refractory cases. In this open-label, single-arm, pilot study, third-party, single-donor FMT was administered in combination with systemic corticosteroids to participants with high-risk acute LGI GVHD, with a focus on treatment-naïve cases. Participants were scheduled to receive 1 induction dose (15 capsules per day for 2 consecutive days), followed by 3 weekly maintenance doses, consisting of 15 capsules per dose. The primary end point of the study was feasibility, which would be achieved if ≥80% of participants able to swallow ≥40 of the 75 scheduled capsules. Ten participants (9 treatment-naïve; 1 steroid-refractory) were enrolled and treated. The study met the primary end point, with 9 of 10 participants completing all eligible doses. Organ-specific LGI complete response rate at day 28 was 70%. Initial clinical response was observed within 1 week for all responders, and clinical responses were durable without recurrent LGI GVHD in complete responders. Exploratory analyses suggest that alpha diversity increased after FMT. Although recipient microbiome composition never achieved a high degree of donor similarity, expansion of donor-derived species and increases in tryptophan metabolites and short-chain fatty acids were observed within the first 7 days after FMT. Investigation into the use of microbiome-targeted interventions earlier in the treatment paradigm for acute LGI GVHD is warranted. This trial was registered at www.ClinicalTrials.gov as #NCT04139577.

Long- and short-term effects of fecal microbiota transplantation on antibiotic resistance genes: results from a randomized placebo-controlled trial.

In small series, third-party fecal microbiota transplantation (FMT) has been successful in decolonizing the gut from clinically relevant antibiotic resistance genes (ARGs). Less is known about the short- and long-term effects of FMT on larger panels of ARGs. We analyzed 226 pre- and post-treatment stool samples from a randomized placebo-controlled trial of FMT in 100 patients undergoing allogeneic hematopoietic cell transplantation or receiving anti-leukemia induction chemotherapy for 47 ARGs. These patients have heavy antibiotic exposure and a high incidence of colonization with multidrug-resistant organisms. Samples from each patient spanned a period of up to 9 months, allowing us to describe both short- and long-term effects of FMT on ARGs, while the randomized design allowed us to distinguish between spontaneous changes vs. FMT effect. We find an overall bimodal pattern. In the first phase (days to weeks after FMT), low-level transfer of ARGs largely associated with commensal healthy donor microbiota occurs. This phase is followed by long-term resistance to new ARGs as stable communities with colonization resistance are formed after FMT. The clinical implications of these findings are likely context-dependent and require further research. In the setting of cancer and intensive therapy, long-term ARG decolonization could translate into fewer downstream infections.

Fecal microbiota transplantation stimulates type 2 and tolerogenic immune responses in a mouse model.

OBJECTIVES: Clostridioides difficile infection (CDI) is the leading hospital-acquired infection in North America. While previous work on fecal microbiota transplantation (FMT), a highly effective treatment for CDI, has focused on colonization resistance mounted against C. difficile by FMT-delivered commensals, the effects of FMT on host gene expression are relatively unexplored. This study aims to identify transcriptional changes associated with FMT, particularly changes associated with protective immune responses. METHODS: Gene expression was assessed on day 2 and day 7 after FMT in mice after antibiotic-induced dysbiosis. Flow cytometry was also performed on colon and mesenteric lymph nodes at day 7 to investigate changes in immune cell populations. RESULTS: FMT administration after antibiotic-induced dysbiosis successfully restored microbial alpha diversity to levels of donor mice by day 7 post-FMT. Bulk RNA sequencing of cecal tissue at day 2 identified immune genes, including both pro-inflammatory and Type 2 immune pathways as upregulated after FMT. RNA sequencing was repeated on day 7 post-FMT, and expression of these immune genes was decreased along with upregulation of genes associated with restoration of intestinal homeostasis. Immunoprofiling on day 7 identified increased colonic CD45+ immune cells that exhibited dampened Type 1 and heightened regulatory and Type 2 responses. These include an increased abundance of eosinophils, alternatively activated macrophages, Th2, and T regulatory cell populations. CONCLUSION: These results highlight the impact of FMT on host gene expression, providing evidence that FMT restores intestinal homeostasis after antibiotic treatment and facilitates tolerogenic and Type 2 immune responses.

Assessment of Faecal Microbiota Transplant Stability in Deep-Freeze Conditions: A 12-Month Ex Vivo Viability Analysis.

BACKGROUND: Faecal microbiota transplantation (FMT) is an established treatment for Clostridioides difficile infection and is under investigation for other conditions. The availability of suitable donors and the logistics of fresh stool preparation present challenges, making frozen, biobanked stools an attractive alternative. AIMS: This study aimed to evaluate the long-term viability of bacterial populations in faecal samples stored at -80°C for up to 12 months, supporting the feasibility of using frozen grafts for FMT. METHODS: Fifteen faecal samples from nine healthy donors were processed, mixed with cryoprotectants and stored at -80°C. Samples were assessed at baseline and after 3, 6 and 12 months using quantitative culturing methods to determine the concentration of live bacteria. RESULTS: Quantitative analysis showed no significant decrease in bacterial viability over the 12-month period for both aerobic and anaerobic cultures (p = 0.09). At all timepoints, the coefficients of variability in colony-forming unit (CFU) counts were greater between samples (102 ± 21% and 100 ± 13% for aerobic and anaerobic cultures, respectively) than the variability between measurements of the same sample (30 ± 22% and 30 ± 19%). CONCLUSIONS: The study confirmed that faecal microbiota can be preserved with high viability in deep-freeze storage for up to a year, making allogenic FMT from biobanked samples a viable and safer option for patients. However, a multidonor approach may be beneficial to mitigate the risk of viability loss in any single donor sample.

Fecal microbiota transplant on Escherichia-Shigella gut composition and its potential role in the treatment of generalized anxiety disorder: A systematic review.

BACKGROUND: The gut-brain-axis has a role in mental health disorders. In people with generalized anxiety disorder, GAD,1 normal flora Escherichia-Shigella, are significantly elevated. Fecal microbiota transplant, FMT,2 has been used to alter the gut composition in unhealthy individuals. There may be a role for FMT in the treatment of GAD to improve the gut-brain-axis. METHODS: A systematic review of literature was conducted on articles published in PubMed, CINAHL Plus, Scopus, Cochrane Library, and Wed of Science from 2000 to 2022 that analyzed FMT as a modality to alter the gut microbiome in which Escherichia-Shigella levels were quantified and reported. RESULTS: Of 1916 studies identified, 14 fit criteria and were included. Recipients undergoing FMT procedures had at least one enteric diagnosis and increased percentages of Escherichia-Shigella pre-FMT. Five studies on recurrent Clostridioides difficile infection, three irritable bowel syndrome, two ulcerative colitis, one ulcerative colitis and recurrent Clostridioides difficile infection, one acute intestinal and chronic graft-vs-host disease, one pouchitis, and one slow transit constipation. 10 articles (71.4 %) showed decreased levels of Escherichia-Shigella post-FMT compared to pre-FMT. Four studies claimed the results were significant (40 %). LIMITATIONS: Limitations include potential bias in study selection, study methods of analysis, and generalization of results. CONCLUSIONS: The gut-brain-axis has a role in GAD. Those with GAD have significantly higher Escherichia-Shigella compared to those without GAD. FMT has the potential to decrease Escherichia-Shigella in patients with GAD to positively alter the gut-brain-axis as a potential for future GAD treatment.

Evidence-Based Approach to Chronic Antibiotic Refractory Pouchitis: A Review.

BACKGROUND: Chronic antibiotic refractory pouchitis after restorative proctocolectomy with IPAA, characterized by at least 4 weeks of pouchitis symptoms that have not responded to standard antibiotic therapy, presents a therapeutic challenge for patients and health care providers. OBJECTIVE: The aim of this narrative review was to summarize the current evidence regarding the management of chronic antibiotic refractory pouchitis. DATA SOURCES: Studies were identified through a search of the PubMed database from the National Library of Medicine. STUDY SELECTION: We included case series, cohort studies, randomized controlled trials, and systematic reviews with meta-analyses that addressed chronic antibiotic refractory pouchitis management, with prioritization of data published within the past 3 to 5 years. INTERVENTION: Studies examining pharmacologic and select nonpharmacologic interventions were included. MAIN OUTCOME MEASURE: Outcomes measures included clinical, endoscopic, and histologic end points. RESULTS: Mesalamine has demonstrated efficacy in symptom improvement but no improvement in quality of life. Budesonide has demonstrated high rates of clinical remission that have mostly been sustained in a small number of patients. Anti-tumor necrosis factor therapies have demonstrated efficacy in reaching clinical and even endoscopic end points, although rates of treatment discontinuation were not insignificant. Limited evidence is encouraging for the use of ustekinumab in achieving clinical response. Data for vedolizumab are favorable across clinical, endoscopic, and histologic end points, including one of the only randomized, placebo-controlled trials. Nonmedication therapies, including hyperbaric oxygen therapy and fecal microbiota transplant, have undergone limited evaluation, and concerns about the ultimate accessibility of these therapies remain. LIMITATIONS: Overall, studies assessing therapeutic options for chronic antibiotic refractory pouchitis are mostly limited to case series and retrospective studies with small sample sizes. CONCLUSIONS: Biologic therapies have demonstrated efficacy in the management of chronic antibiotic refractory pouchitis and offer a steroid-sparing option for refractory disease. Nonpharmacologic therapies, including hyperbaric oxygen and fecal microbiota transplant, require further exploration. See video from symposium .

Gut-Liver-Brain Axis and Alcohol Use Disorder: Treatment Potential of Fecal Microbiota Transplantation.

PURPOSE: Chronic alcohol use is a major cause of liver damage and death. In the United States, multiple factors have led to low utilization of pharmacotherapy for alcohol use disorder (AUD), including lack of provider knowledge and comfort in prescribing medications for AUD. Alcohol consumption has direct effects on the gut microbiota, altering the diversity of bacteria and leading to bacterial overgrowth. Growing evidence suggests that alcohol's effects on the gut microbiome may contribute to increased alcohol consumption and progression of alcohol-associated liver disease (ALD). This article reviews human and preclinical studies investigating the role of fecal microbiota transplantation (FMT) in ameliorating alcohol-associated alterations to the liver, gut, and brain resulting in altered behavior; it also discusses the therapeutic potential of FMT. SEARCH METHODS: For this narrative review, a literature search was conducted in September 2022 of PubMed, Web of Science Core Collection, and Google Scholar to identify studies published between January 2012 and September 2022. Search terms used included "fecal microbiota transplantation" and "alcohol." SEARCH RESULTS: Most results of the literature search were review articles or articles on nonalcoholic fatty liver disease; these were excluded. Of the remaining empirical manuscripts, very few described clinical or preclinical studies that were directly investigating the effects of FMT on alcohol drinking or related behaviors. Ultimately, 16 studies were included in the review. DISCUSSION AND CONCLUSIONS: The literature search identified only a few studies that were directly investigating the effect of FMT on ALD or alcohol drinking and related behaviors. Largely proof-of-concept studies, these findings demonstrate that alcohol can alter the gut microbiome and that the microbiome can be transferred between humans and rodents to alter affective behaviors frequently associated with increased alcohol use. Other studies have shown promise of FMT or other probiotic supplementation in alleviating some of the symptoms associated with ALD and drinking. These results show that the implementation of FMT as a therapeutic approach is still in the investigatory stages.

Current perspectives on fecal microbiota transplantation in inflammatory bowel disease.

Fecal microbiota transplantation (FMT) has emerged as a promising therapeutic modality within the domain of inflammatory bowel disease (IBD). While FMT has secured approval and demonstrated efficacy in addressing recurrent and refractory Clostridioides difficile infection, its application in IBD remains an area of active exploration and research. The current status of FMT in IBD reflects a nuanced landscape, with ongoing investigations delving into its effectiveness, safety and optimal implementation. Early-stage clinical trials and observational studies have provided insights into the potential of FMT to modulate the dysbiotic gut microbiota associated with IBD, aiming to mitigate inflammation and promote mucosal healing. However, considerable complexities persist, including variations in donor selection, treatment protocols and outcome assessments. Challenges in standardizing FMT protocols for IBD treatment are compounded by the dynamic nature of the gut microbiome and the heterogeneity of IBD itself. Despite these challenges, enthusiasm for FMT in IBD emanates from its capacity to address gut microbial dysbiosis, signifying a paradigm shift towards more comprehensive approaches in IBD management. As ongoing research progresses, an enhanced understanding of FMT's role in IBD therapy is anticipated. This article synthesizes the current status of FMT in IBD, elucidating the attendant challenges and aspiring towards the refinement of its application for improved patient outcomes.

Long-term beneficial effect of faecal microbiota transplantation on colonisation of multidrug-resistant bacteria and resistome abundance in patients with recurrent Clostridioides difficile infection.

BACKGROUND: Multidrug-resistant (MDR) bacteria are a growing global threat, especially in healthcare facilities. Faecal microbiota transplantation (FMT) is an effective prevention strategy for recurrences of Clostridioides difficile infections and can also be useful for other microbiota-related diseases. METHODS: We study the effect of FMT in patients with multiple recurrent C. difficile infections on colonisation with MDR bacteria and antibiotic resistance genes (ARG) on the short (3 weeks) and long term (1-3 years), combining culture methods and faecal metagenomics. RESULTS: Based on MDR culture (n = 87 patients), we notice a decrease of 11.5% in the colonisation rate of MDR bacteria after FMT (20/87 before FMT = 23%, 10/87 3 weeks after FMT). Metagenomic sequencing of patient stool samples (n = 63) shows a reduction in relative abundances of ARGs in faeces, while the number of different resistance genes in patients remained higher compared to stools of their corresponding healthy donors (n = 11). Furthermore, plasmid predictions in metagenomic data indicate that patients harboured increased levels of resistance plasmids, which appear unaffected by FMT. In the long term (n = 22 patients), the recipients' resistomes are still donor-like, suggesting the effect of FMT may last for years. CONCLUSIONS: Taken together, we hypothesise that FMT restores the gut microbiota to a composition that is closer to the composition of healthy donors, and potential pathogens are either lost or decreased to very low abundances. This process, however, does not end in the days following FMT. It may take months for the gut microbiome to re-establish a balanced state. Even though a reservoir of resistance genes remains, a notable part of which on plasmids, FMT decreases the total load of resistance genes.

Protocol for the Gut Bugs in Autism Trial: a double-blind randomised placebo-controlled trial of faecal microbiome transfer for the treatment of gastrointestinal symptoms in autistic adolescents and adults.

INTRODUCTION: Autism (formally autism spectrum disorder) encompasses a group of complex neurodevelopmental conditions, characterised by differences in communication and social interactions. Co-occurring chronic gastrointestinal symptoms are common among autistic individuals and can adversely affect their quality of life. This study aims to evaluate the efficacy of oral encapsulated faecal microbiome transfer (FMT) in improving gastrointestinal symptoms and well-being among autistic adolescents and adults. METHODS AND ANALYSIS: This double-blind, randomised, placebo-controlled trial will recruit 100 autistic adolescents and adults aged 16-45 years, who have mild to severe gastrointestinal symptoms (Gastrointestinal Symptoms Rating Scale (GSRS) score ≥2.0). We will also recruit eight healthy donors aged 18-32 years, who will undergo extensive clinical screening. Recipients will be randomised 1:1 to receive FMT or placebo, stratified by biological sex. Capsules will be administered over two consecutive days following an overnight bowel cleanse with follow-up assessments at 6, 12 and 26 weeks post-treatment. The primary outcome is GSRS score at 6 weeks. Other assessments include anthropometry, body composition, hair cortisol concentration, gut microbiome profile, urine/plasma gut-derived metabolites, plasma markers of gut inflammation/permeability and questionnaires on general well-being, sleep quality, physical activity, food diversity and treatment tolerability. Adverse events will be recorded and reviewed by an independent data monitoring committee. ETHICS AND DISSEMINATION: Ethics approval for the study was granted by the Central Health and Disability Ethics Committee on 24 August 2021 (reference number: 21/CEN/211). Results will be published in peer-reviewed journals and presented to both scientific and consumer group audiences. TRIAL REGISTRATION NUMBER: ACTRN12622000015741.

Horizontal gene transfer after faecal microbiota transplantation in adolescents with obesity.

BACKGROUND: Horizontal gene transfer (HGT) describes the transmission of DNA outside of direct ancestral lineages. The process is best characterised within the bacterial kingdom and can enable the acquisition of genetic traits that support bacterial adaptation to novel niches. The adaptation of bacteria to novel niches has particular relevance for faecal microbiota transplantation (FMT), a therapeutic procedure which aims to resolve gut-related health conditions of individuals, through transplanted gut microbiota from healthy donors. RESULTS: Three hundred eighty-one stool metagenomic samples from a placebo-controlled FMT trial for obese adolescents (the Gut Bugs Trial) were analysed for HGT, using two complementary methodologies. First, all putative HGT events, including historical HGT signatures, were quantified using the bioinformatics application WAAFLE. Second, metagenomic assembly and gene clustering were used to assess and quantify donor-specific genes transferred to recipients following the intervention. Both methodologies found no difference between the level of putative HGT events in the gut microbiomes of FMT and placebo recipients, post-intervention. HGT events facilitated by engrafted donor species in the FMT recipient gut at 6 weeks post-intervention were identified and characterised. Bacterial strains contributing to this subset of HGT events predominantly belonged to the phylum Bacteroidetes. Engraftment-dependent horizontally transferred genes were retained within recipient microbiomes at 12 and 26 weeks post-intervention. CONCLUSION: Our study suggests that novel microorganisms introduced into the recipient gut following FMT have no impact on the basal rate of HGT within the human gut microbiome. Analyses of further FMT studies are required to assess the generalisability of this conclusion across different FMT study designs and for the treatment of different gut-related conditions. Video Abstract.

Evaluation of the safety and efficacy of fecal microbiota transplantations in bottlenose dolphins (Tursiops truncatus) using metagenomic sequencing.

AIMS: Gastrointestinal disease is a leading cause of morbidity in bottlenose dolphins (Tursiops truncatus) under managed care. Fecal microbiota transplantation (FMT) holds promise as a therapeutic tool to restore gut microbiota without antibiotic use. This prospective clinical study aimed to develop a screening protocol for FMT donors to ensure safety, determine an effective FMT administration protocol for managed dolphins, and evaluate the efficacy of FMTs in four recipient dolphins. METHODS AND RESULTS: Comprehensive health monitoring was performed on donor and recipient dolphins. Fecal samples were collected before, during, and after FMT therapy. Screening of donor and recipient fecal samples was accomplished by in-house and reference lab diagnostic tests. Shotgun metagenomics was used for sequencing. Following FMT treatment, all four recipient communities experienced engraftment of novel microbial species from donor communities. Engraftment coincided with resolution of clinical signs and a sustained increase in alpha diversity. CONCLUSION: The donor screening protocol proved to be safe in this study and no adverse effects were observed in four recipient dolphins. Treatment coincided with improvement in clinical signs.

Sterile Fecal Microbiota Transplantation Boosts Anti-Inflammatory T-Cell Response in Ulcerative Colitis Patients.

Ulcerative colitis is a chronic immune-mediated disease of unclear etiology, affecting people of different ages and significantly reducing the quality of life. Modern methods of therapy are mainly represented by anti-inflammatory drugs and are not aimed at a specific pathogenetic factor. In this study, we investigated the effect of transplantation of sterile stool filtrate from healthy donors on the induction of anti-inflammatory immune mechanisms. It was shown that performing such a procedure in patients with ulcerative colitis caused the appearance of T helper cells in the blood, which reacted to the content of sterile stool filtrates in an antigen-specific manner and produced IL-10. At the same time, cells of the same patients before therapy in response to the addition of sterile stool filtrates were less reactive and predominantly produced IL-4, indicating its pro-inflammatory skewing. The obtained data demonstrated the effect of an anti-inflammatory shift in the T-helper response after transplantation of sterile stool filtrate, which increased and persisted for at least three months after the procedure.