The integration of fecal microbiota transplantation (FMT) with immune checkpoint inhibitors (ICIs) presents a promising approach for enhancing cancer treatment efficacy and overcoming therapeutic resistance. This review critically examines the controversial effects of FMT on ICIs outcomes and elucidates the underlying mechanisms. We investigate how FMT modulates gut microbiota composition, microbial metabolite profiles, and the tumor microenvironment, thereby influencing ICIs effectiveness. Key factors influencing FMT efficacy, including donor selection criteria, recipient characteristics, and administration protocols, are comprehensively discussed. The review delineates strategies for optimizing FMT formulations and systematically monitoring post-transplant microbiome dynamics. Through a comprehensive synthesis of evidence from clinical trials and preclinical studies, we elucidate the potential benefits and challenges of combining FMT with ICIs across diverse cancer types. While some studies report improved outcomes, others indicate no benefit or potential adverse effects, emphasizing the complexity of host-microbiome interactions in cancer immunotherapy. We outline critical research directions, encompassing the need for large-scale, multi-center randomized controlled trials, in-depth microbial ecology studies, and the integration of multi-omics approaches with artificial intelligence. Regulatory and ethical challenges are critically addressed, underscoring the imperative for standardized protocols and rigorous long-term safety assessments. This comprehensive review seeks to guide future research endeavors and clinical applications of FMT-ICIs combination therapy, with the potential to improve cancer patient outcomes while ensuring both safety and efficacy. As this rapidly evolving field advances, maintaining a judicious balance between openness to innovation and cautious scrutiny is crucial for realizing the full potential of microbiome modulation in cancer immunotherapy.

Reliable engraftment assessment of donor microbial communities and individual strains is an essential component of characterizing the pharmacokinetics of microbiota transplant therapies (MTTs). Recent methods for measuring donor engraftment use whole-genome sequencing and reference databases or metagenome-assembled genomes (MAGs) to track individual bacterial strains but lack the ability to disambiguate DNA that matches both donor and patient microbiota. Here, we describe a new, cost-efficient analytic pipeline, MAGEnTa, which compares post-MTT samples to a database comprised MAGs derived directly from donor and pre-treatment metagenomic data, without relying on an external database. The pipeline uses Bayesian statistics to determine the likely sources of ambiguous reads that align with both the donor and pre-treatment samples. MAGEnTa recovers engrafted strains with minimal type II error in a simulated dataset and is robust to shallow sequencing depths in a downsampled dataset. Applying MAGEnTa to a dataset from a recent MTT clinical trial for ulcerative colitis, we found the results to be consistent with 16S rRNA gene SourceTracker analysis but with added MAG-level specificity. MAGEnTa is a powerful tool to study community and strain engraftment dynamics in the development of MTT-based treatments that can be integrated into frameworks for functional and taxonomic analysis.

The development of fecal microbiota transplantation and defined live biotherapeutic products for the treatment of human disease has been an empirically driven process yielding a notable success of approved drugs for the treatment of recurrent Clostridioides difficile infection. Assessing the potential of this therapeutic modality in other indications with mixed clinical results would benefit from consistent quantitative frameworks to characterize drug potency and composition and to assess the impact of dose and composition on the frequency and duration of strain engraftment. Monitoring these drug properties and engraftment outcomes would help identify minimally sufficient sets of microbial strains to treat disease and provide insights into the intersection between microbial function and host physiology. Broad and correct usage of strain detection methods is essential to this advancement. This article describes strain detection approaches, where they are best applied, what data they require, and clinical trial designs that are best suited to their application.

Lyophilised encapsulated faecal microbiota provides a practical and cost-effective treatment option to patients with recurrent Clostridioides difficile infection. This study focused on quality assurance of an enteric-coated capsule formulation of FMT as a medicinal product by evaluating bacterial composition, diversity and viability through manufacturing steps and upon product storage at a range of temperatures. Faecal donations from pre-screened healthy individuals (n = 5) were processed according to a published protocol into one or more treatments; 5 capsules = 1 treatment dose/patient. Culture-independent next-generation 16S rRNA gene sequencing was used to speciate and quantify bacteria using a live-dead cell separation method to discriminate the viable cell load. Species diversity in donor stools aligned with other healthy gut microbiome and remained unchanged through the manufacturing process and after storage at -80 °C for 36 weeks. While diversity indices were consistent, a notable difference was observed between viable and total microbiome, particularly in species richness, which decreased when non-viable or compromised cells were excluded from analysis. Anaerobic species exhibited minimal viability loss despite processing in an aerobic environment. Furthermore, capsules were stable with storage at -20 °C and 2-8 °C, with no significant reduction of total live bacterial load after 24 weeks. In summary, 'live-dead' culture-independent analysis was used to characterise the viable faecal microbiome, which retained a diversity of bacterial species, including anaerobes, through manufacture and after storage in capsules for up to 36 weeks. These data support the comparable effectiveness of lyophilised encapsulated FMT to other formulations and delivery methods.

Faecal microbiota transplantation (FMT) has emerged as a transformative therapy for Clostridioides difficile infections and shows promise for various GI and systemic diseases. However, the poor patient acceptability and accessibility of 'conventional' FMT, typically administered via colonoscopies or enemas, hinders its widespread clinical adoption, particularly for chronic conditions. Oral administration of FMT (OralFMT) overcomes these limitations, yet faces distinct challenges, including a significant capsule burden, palatability concerns and poor microbial viability during gastric transit. This review provides a comprehensive analysis of emerging strategies that aim to advance OralFMT by: (1) refining processing technologies (eg, lyophilisation) that enable manufacturing of low-volume FMT formulations for reducing capsule burden and (2) developing delivery technologies that improve organoleptic acceptability and safeguard the microbiota for targeted colonic release. These advancements present opportunities for OralFMT to expand its therapeutic scope, beyond C. difficile infections, towards chronic GI conditions requiring frequent dosing regimens. While this review primarily focuses on optimising OralFMT delivery, it is important to contextualise these advancements within the broader shift towards defined microbial consortia. Live biotherapeutic products (LBPs) offer an alternative approach, yet the interplay between OralFMT and LBPs in clinical practice remains unresolved. We postulate that continued innovation in OralFMT and LBPs via a multidisciplinary approach can further increase therapeutic efficacy and scalability by enabling disease site targeting, co-delivery of therapeutic compounds and overcoming colonisation resistance. Realising these goals positions OralFMT as a cornerstone of personalised care across a range of diseases rooted in microbiome health.

Clinical data on oral fecal microbiota transplantation (FMT), a promising therapy for Crohn's disease (CD), are limited. Herein, we determined the short-term safety and feasibility of FMT for pediatric patients with active CD.

In this open-label, parallel-group, single-center prospective trial, patients with active CD were treated with oral FMT capsules combined with partial enteral nutrition (PEN) (80%). The control group comprised pediatric patients with active CD treated with PEN (80%) and immunosuppressants. Thirty-three patients (11.6 ± 1.82 years)-17 in the capsule and 16 in the control groups-were analyzed. Data regarding the adverse events, clinical reactions, intestinal microbiome composition, and biomarker parameters were collected and compared post-treatment.

At week 10, the clinical and endoscopic remission rates did not differ between the two groups. By week 10, the mean fecal calprotectin level, C-reactive protein level, erythrocyte sedimentation rate, simple endoscopic score for CD, and pediatric CD activity index decreased significantly in the capsule group (all P < 0.05). The main adverse event was mild-to-moderate constipation. Core functional genera, Agathobacter, Akkermansia, Roseburia, Blautia, Subdoligranulum, and Faecalibacterium, were lacking pre-treatment. Post-treatment, the implantation rates of these core functional genera increased significantly, which positively correlated with the anti-inflammatory factor, interleukin (IL)-10, and negatively correlated with the pro-inflammatory factor, IL-6. The combination of these six functional genera distinguished healthy children from those with CD (area under the curve = 0.96).

Oral FMT capsules combined with PEN (80%) could be an effective therapy for children with active CD. The six core functional genera identified here may be candidate biomarkers for identifying children with CD.

ClinicalTrials.gov, retrospectively registered, ID# NCT05321758, NCT05321745, date of registration: 2022-04-04.

Fecal microbiota transplantation (FMT) is the most effective therapy for preventing recurrent Clostridioides difficile infection (rCDI). However, the impact of FMT formulations and storage conditions on bacterial viability, community structure, functionality, and clinical efficacy remains under-investigated. We studied the effect of different storage conditions on the bacterial viability (live/dead staining and cell sorting), community structure (16S rDNA analysis), and metabolic functionality (fermentation) of frozen and lyophilized FMT formulations. The clinical success rates of rCDI patients were correlated retrospectively with FMT formulations, storage durations, and host factors using the Edmonton FMT program database. Bacterial viability remained at 10-20% across various storage conditions and formulations and was comparable to that of fresh FMT. Live and dead bacterial fractions in both frozen and lyophilized FMT preparations exhibited distinct community structures. Storage durations, but not temperatures, negatively affected bacterial diversity. More short-chain fatty acids were found in the metabolomic profiling of in vitro fermentation products using lyophilized than frozen FMT. Clinical success rates in 537 rCDI patients receiving a single dose of FMT were not significantly different among the three formulations. However, longer storage durations and advanced recipient age negatively impacted clinical efficacy. Together, our findings suggest that FMT formulations and storage durations should be considered when establishing guidelines for product shelf life for optimal treatment outcomes.

Freezing donor fecal microbiota has improved fecal microbiota transplantation (FMT) for recurrent C. difficile infection (CDI), achieving short-term effectiveness similar to fresh-samples. Research shows frozen fecal matter remains effective for up to 12-months at -80 °C.

To assess how long-term-freezing and thawing affect the viability, microbial composition, and clinical efficacy of frozen-stools for FMT.

Stool samples from three donors were processed into 18 aliquots, thawed at intervals over two years, and analyzed for cell viability and microbial load. Microbiota composition was assessed through 16S-sequencing, with diversity evaluated using the Shannon-index and Principal-Coordinates-Analysis based on Bray-Curtis-distance (α/β-diversity). The same donors provided fecal material for a total of 23 FMT procedures, including 15 for CDI and 8 off-label.

We found that donor stools frozen for two years contained viable bacteria comparable to fresh samples, with anaerobic and aerobic species remaining viable for 24 months. Despite a reduction in colony-forming-units, FMT was successful in 71.4 % and 100 % of the cases at one year and at the end of follow-up, respectively. Most bacterial changes occurred among anaerobic species (Blautia producta and Bifidobacterium adolescentis), increasing post-thawing. Notably, specific taxa, (C. aerofaciens and Erysipelotrichaceae_Cc115), showed significant unexplained increase.

Long-term-stool-storage enhances FMT accessibility without compromising its success, despite taxonomic changes after 24 months.

Fecal microbiota transplantation (FMT) effectively treats recurrent Clostridioides difficile infection (rCDI), typically administered as a fresh or frozen stool suspension through colonoscopy, nasojejunal tube, or oral capsules. Lyophilized fecal microbiota (LFM) are an alternative to frozen FM products. We aimed to assess whether lyophilization affects bacterial viability and metabolite levels and to develop LFM capsules for clinical use in Germany. Fecal donations from pre-screened volunteers were aliquoted and analyzed through microbial cell counting, bacterial culture, 16S rRNA gene amplicon sequencing, and bile acid assays. Results showed higher counts of viable bacterial cells and cultured anaerobes in unprocessed stool compared to freshly processed stool (p = 0.012 and p < 0.001, respectively). No significant difference in viable bacterial counts was found between freshly processed (day 0), lyophilized (day 3) and frozen FM (day 3) (p = 0.15), nor between freshly processed (day 0), lyophilized (days 30 and 90) and frozen FM (day 30) (p = 0.07). lyophilization did not significantly impact bile acid and 16S rRNA profiling. Encapsulation of lyophilized powder required fewer capsules (10-14) than frozen capsules (30). LFM products are a practical, viable alternative to frozen and fresh FM products, potentially improving storage and patient acceptance.

Faecal microbiota transplantation (FMT) is increasingly used for diseases associated with a disrupted intestinal microbiome, mainly Clostridioides difficile infection. Encapsulated FMT is a patient-friendly application method that improves accessibility and convenience. Capsule processing may be standardised, but validation protocols are warranted. This review aimed to describe published validation methods for encapsulated FMT. Original studies reporting using encapsulated faecal formulations were included, regardless of indication. Studies were excluded if they did not address processing and validation or used non-donor-derived content. We conducted a comprehensive scoping review, implementing a systematic search strategy in PubMed, Embase and Web of Science. Processing data and validation methods were registered during full-text analysis and combined to create an overview of approaches for assessing quality in encapsulated FMT processing. The searches identified 324 unique studies, of which 44 were included for data extraction and analysis. We identified eight validation covariables: donor selection, pre-processing, preservation, oxygen-sparing processing, microbial count, viability, engraftment and clinical effect outcomes, from which we constructed a model for quality assessment of encapsulated FMT that exhaustively categorised processing details and validation measures. Our model comprised three domains: (1) Processing (donor selection and processing protocol), (2) Content analysis (microbiota measures and dose measures) and (3) Clinical effect (engraftment and clinical outcomes). No studies presented a reproducible capsule protocol; their validation strategies were sparse and divergent. The validation of FMT capsules is heterogeneous, and processing requires relevant standardisation protocols, mainly focusing on capsule content. Future studies should report validation covariables to enable accurate comparative assessments of clinical effects.

Clostridioides difficile infection (CDI) is the most common cause of healthcare-associated infections in US hospitals, with 15%-30% of patients experiencing recurrence. The aim of our randomized, double-blind clinical trial was to assess the efficacy of capsule-delivered fecal microbiota transplant (FMT) versus placebo in reducing recurrent diarrhea and CDI recurrence. The secondary aim was FMT safety assessment.

Between 2018 and 2022, Veterans across the Veterans Health Administration system with recurrent CDI who responded to antibiotic treatment were randomized in a 1:1 ratio to oral FMT or placebo capsules. Randomization was stratified by number of prior CDI recurrences (1 or ≥2). The primary endpoint was clinical recurrence by day 56, defined as >3 unformed stools daily for ≥2 days with or without laboratory confirmation of C. difficile, or death within 56 days.

The study was stopped due to futility after meeting prespecified criteria. Of 153 participants (76 FMT, 77 placebo) with an average age of 66.5 years, 25 participants (32.9%) in the FMT arm and 23 (29.9%) in the placebo arm experienced the primary endpoint of diarrhea and possible or definite CDI recurrence or death within 56 days of capsule administration (absolute difference, 3.0% [95% confidence interval, -11.7% to 17.7%]). Stratification by number of recurrences revealed no statistically significant differences. There were no clinically important differences in adverse events.

FMT therapy versus placebo did not reduce CDI recurrence or death at 56 days. There were no meaningful differences in adverse events between treatment groups.

NCT03005379.

Microbiota transplant therapy (MTT) is an emerging treatment for ulcerative colitis (UC). One proposed mechanism for the benefit of MTT is through engraftment of donor microbiota; however, engraftment kinetics are unknown. We identified SourceTracker as an efficient method both to determine engraftment and for the kinetic study of engrafting donor taxa to aid in determining the mechanism of how this therapy may treat UC.

Ulcerative colitis patients received either encapsulated (drug name MTP-101C) or placebo capsules daily for 8 weeks followed by a 4-week washout period. Amplicon sequence data from donors and patients were analyzed using the Bayesian algorithm SourceTracker.

Twenty-seven patients were enrolled, 14 to placebo and 13 to MTT. Baseline Shannon and Chao1 indices negatively correlated with week 12 donor engraftment for patients treated with active drug capsules but not for placebo patients. SourceTracker engraftment positively correlated with the week 12 distance from donors measured using the Bray-Curtis similarity metric in treated patients but not with placebo. Engraftment at week 12 was significantly higher in the MTT group than in the placebo group. We identified engrafting taxa from donors in our patients and quantified the proportion of donor similarity or engraftment during weeks 1 through 8 (active treatment) and week 12, 4 weeks after the last dose.

SourceTracker can be used as a simple and reliable method to quantify donor microbial community engraftment and donor taxa contribution in patients with UC and other inflammatory conditions treated with MTT.

Faecal microbiota transplantation (FMT) is an established treatment for recurrent Clostridioides difficile infection (CDI). This study aimed to identify calprotectin and microbiome characteristics as potential biomarkers of FMT success.

We conducted a prospective study of patients who underwent oral FMT (single dose of 4-5 capsules) for recurrent CDI (January 2018 to December 2022). Samples were collected at three time points: at CDI diagnosis, within 24 hours before FMT administration, and 30 days post-FMT. Calprotectin levels were assessed and the V4 region of the 16S rRNA gene was sequenced to analyse the microbiota composition. Sequencing data analysis and statistical analysis were performed using MOTHUR and R.

Ninety-seven patients underwent FMT (totalling 105 procedures). A total of 221 samples were processed, including 21 donor samples, 24 capsule contents, and 176 patient faecal samples (39 at diagnosis, 63 pre-FMT, and 74 post-FMT). FMT achieved an overall success rate of 85.1% (86/101 cases). The abundance of Bacteroides, Ruminococcus, Megamonas, and certain Prevotella operational taxonomic units was significantly higher in capsules associated with 100% success compared with less effective capsules. FMT engraftment was observed in 95% of patients with favourable outcomes versus 62% of those with recurrences (p 0.006). Additionally, a negative correlation was found between calprotectin levels and specific microbial genera, suggesting an association with successful outcomes.

This study highlights differences in the evolution of faecal microbiota, bacterial engraftment, and inflammation markers (e.g. calprotectin) between patients with varying FMT outcomes. Potential biomarkers for successful FMT were identified, providing valuable insights for optimizing FMT strategies.

Preventing hepatic encephalopathy (HE) recurrence in cirrhosis, which is associated with an altered gut-liver-brain axis, is an unmet need. Benefits of fecal microbiota transplantation (FMT) have been shown in phase I studies, but route and dose-related questions remain.

We performed a phase II randomized, placebo-controlled, double-blind, clinical trial of capsule and enema FMT in patients with cirrhosis and HE on lactulose and rifaximin. Participants were randomized into four groups (3 active doses; 2 active and 1 placebo dose; 1 active and 2 placebo doses; 3 placebo doses). Each patient received two capsules and one enema (either placebo or FMT) and were followed for 6 months. The primary outcome was FMT-related (serious) adverse events ([s]AEs)/AEs using intention-to-treat analysis. Secondary outcomes were HE recurrence, all-cause hospitalizations, death, donor engraftment, and quality-of-life. FMT was from a vegan or omnivorous donor.

We enrolled 60 patients (15/group) with similar baseline characteristics. FMT was safe without any FMT-related SAEs/AEs. Overall SAEs (p = 0.96) or death (p = 1.0) were similar. There were significant differences in HE recurrence between groups (p = 0.035, Cramer's V = 0.39). On post hoc analysis, recurrence was highest in the all-placebo vs. any FMT group (40% vs. 9%; odds ratio 0.15, 95% CI 0.04-0.64). Within the FMT groups, HE recurrence rates were similar regardless of route, doses, or donor type. Quality of life improved in FMT-recipient groups. Engraftment was highest in those with high pre-FMT Lachnospiraceae and lower in those whose HE recurred.

In patients with cirrhosis and HE on maximal therapy, FMT regardless of dose, route, or donor was safe without any FMT-related AEs. On post hoc analysis, HE recurrence was highest in the placebo-only group and linked with lower baseline Lachnospiraceae and reduced donor engraftment.

Patients with hepatic encephalopathy (HE) already on maximal therapy could have recurrences, which worsen prognosis and are not prioritized for liver transplant. In this phase II, double-blind, randomized, placebo-controlled trial in patients with cirrhosis and prior overt HE, we found that fecal microbiota transplant (FMT) was safe and well tolerated regardless of route of delivery (oral or enema), number of doses (1 through 3), or donor type (vegan or omnivorous). HE recurrence, which was a key secondary endpoint, was different between groups and, on post hoc analysis, lowest in groups that received any FMT. Donor engraftment was higher in those with higher relative abundance of Lachnospiraceae, which was associated with lower HE recurrence.

The spectrum of metabolic dysfunction-associated steatotic liver disease (MASLD) is highly prevalent, affecting 30% of the world's population, with a significant risk of hepatic and cardiometabolic complications. Different stages of MASLD are accompanied by distinct gut microbial profiles, and several microbial components have been implicated in MASLD pathophysiology. Indeed, earlier studies demonstrated that hepatic necroinflammation was reduced in individuals with MASLD after allogenic faecal microbiota transplantation (FMT) from healthy donors on a vegan diet. Here, we further investigate the therapeutic potential of gut microbiome modulation using a syntrophic combination of next-generation beneficial bacteria with FMT in individuals with advanced MASLD.

This trial is a randomised, double-blind, placebo-controlled study investigating the therapeutic potential of lyophilised faecal microbiota capsules (LFMCs) in individuals with metabolic dysfunction-associated steatohepatitis. In this study, 48 participants will be randomised 1:1 to receive either healthy vegan donor LFMCs or placebo for 24 weeks. In addition, all participants will be supplemented with a set of next-generation beneficial bacteria, including Anaerobutyricum soehngenii, pasteurised Akkermansia muciniphila and Bifidobacterium animalis subsp. lactis, as well as fructo-oligosaccharides. A liver biopsy will be performed at baseline and at the end of the trial. In addition, participants will be assessed through MRI, FibroScan, blood tests, faecal samples and continuous glucose monitoring. The first participant was enrolled on 25 April 2023.

Ethical approval was obtained from the Medical Ethics Committee of the University Medical Centre of Amsterdam. The results of this study will be disseminated through peer-reviewed journals.

The trial is registered on clinicaltrials.gov (NCT05821010).

The study of the microbiota and the microbiome, and specifically the intestinal one, has determined great interest due to the possible association of their alterations with numerous diseases. These include entities as diverse as Crohn's disease, autism, diabetes, cancer or situations as prevalent today as obesity. In view of this situation, different recommendations have been performed regarding the use of probiotics, prebiotics, and postbiotics as modulators of the microbiota and the microbiome, seeking both preventive and therapeutic effects, and faecal material transfer (FMT) is proposed as an alternative. The latter has emerged as the only proven beneficial intervention on the intestinal microbiome, specifically in the treatment of recurrent colitis associated with Clostridioides difficile (R-CDI). In the rest of the entities, the lowering of laboratory costs has favored the study of the microbiome, which is resolved by delivering reports with catalogs of microorganisms, metabolites or supposed biomarkers without consensus on their composition associated with healthy or diseased microbiota and the disease. There is still insufficient evidence in any disease for interventions on the microbiome beyond FMT and R-CDI. Multi- and multi-disciplinary work with extensive research and the application of artificial intelligence in this field may shed light on the questions raised currently. Ethical issues must also be resolved in light of possible interventions within the umbrella of personalized medicine.

Over the last few decades, there have been tremendous advances in our understanding of the role of the gut microbiome in cirrhosis and the clinical sequelae that follow. Progressive dysbiosis and immune dysregulation occur in patients with cirrhosis. In fact, alterations in the gut microbiome occur long before a diagnosis of cirrhosis is made. Understandably, our attention has recently been diverted toward potential modulators of the gut microbiome and the gut-liver axis as targets for treatment. The goal of this review is to highlight the utility of manipulating the gut microbiome with a focus on fecal microbiome transplantation (FMT) in patients with cirrhosis. In addition, we will provide an overview of disease-specific microbial alterations and the resultant impact this has on cirrhosis-related complications.

Fecal microbiota transplantation (FMT) is a therapeutic modality for treating neonatal calf diarrhea. Several practical barriers, including donor selection, fecal collection, and a limited timeframe for FMT, are the main constraints to using fresh feces for implementing on-farm FMT. We report the utility of FMT with pretreated ready-to-use frozen (F) or freeze-dried (FD) microorganisms for treating calf diarrhea. In total, 19 FMT (F-FMT, n = 10 and FD-FMT, n = 9) treatments were conducted. Both FMT treatments were 100% clinically effective; however, multi-omics analysis showed that FD-FMT was superior to F-FMT. Machine learning analysis with SourceTracker confirmed that donor microbiota was retained four times better in the recipient calves treated with FD-FMT than F-FMT. A predictive model based on receiver operating characteristic curve analysis and area under the curve showed that FD-FMT was more discriminative than F-FMT of the observed changes in microbiota and metabolites during disease recovery. These results provide new insights into establishing methods for preparing fecal microorganisms to increase the quality of FMT in animals and may contribute to FMT in humans.

Fecal Microbiota Transplant (FMT) is an effective treatment for recurring Clostridioides Difficile Infections (rCDI). FMT administered via oral capsules (caFMT) offers several practical advantages to conventional liquid FMT. We began using caFMT in 2021 imported from an external institution. Based on similar production methods, we began our own caFMT production in 2022. We aimed to evaluate the quality of our caFMT.

We created a database of all FMT treatments (n = 180) provided by our institution. Quality of all FMT was evaluated by treatment success rates. We compared our caFMT to the imported caFMT.

Our caFMT yielded similar success rates compared to that of the imported caFMT, 65% (CI 95% 58-72%) and 72% (CI 95% 66-79%) respectively. FMT administered via colonoscopy had a significantly higher success rate, 79% (CI 95% 73-85%) than own our caFMT and other routes of administration. The combined success rate of treatments increased notably for all routes of administration when repeating FMT after prior failure.

The fact that our caFMT compared similarly to the imported caFMT was viewed as a success in terms of quality assurance. Our caFMT had a slightly lower success rates compared to data from other studies, but could be affected by several other factors than our FMT-production methods. A lower success rate of caFMT compared to FMT via colonoscopy is acceptable due to the practical advantages offed by caFMT. Our study serves as a practical example, proving that of the standardization of caFMT production is indeed viable.

Faecal microbiota transplantation (FMT) is a highly effective treatment for Clostridioides difficile infection. Its use is backed by solid evidence, but application methods differ. Encapsulated FMT is a non-invasive, patient-friendly and scalable application method that may be preferred over colonoscopy or nasoduodenal tube application.

We describe a detailed protocol, the Glyprotect protocol, for producing glycerol-based capsules to increase FMT accessibility.

Using iterative quality improvement methods, we developed and validated the Glyprotect protocol as a reproducible protocol for cryopreserving minimally processed donor faeces in a standard hospital laboratory setting.

We describe detailed standard operating procedures for producing glycerol-based capsules, including all necessary materials and troubleshooting guidelines. Capsule integrity was tested at various temperatures and pH levels. Flow cytometry was used to measure microbiota counts and dose accuracy.

The Glyprotect protocol has been used for more than 2500 capsule-based FMT treatments and complies with European tissue and cell standards. The protocol is optimised to preserve microbes and minimise modulation of the donated microbiota by removing debris and water, which also reduces the number of capsules needed per FMT treatment. The intestinal microbiota is preserved in glycerol for cryoprotection and to prevent capsule leakage. Each capsule contains 650 µL microbe-glycerol mass, estimated to contain an average of 2.5 × 108 non-specified bacteria.

The Glyprotect protocol enables hospitals and tissue establishments to set up capsule production in a standard laboratory, improving patients' access to FMT. The protocol facilitates the scalability of FMT services because capsule FMT is less time-consuming and less expensive than liquid-suspension FMT applied by colonoscopy or nasojejunal tube.

Not applicable.

The gut microbiome is involved in the pathogenesis of many diseases including polycystic ovarian syndrome (PCOS). Modulating the gut microbiome can lead to eubiosis and treatment of various metabolic conditions. However, there is no proper study assessing the delivery of microbial technology for the treatment of such conditions. The present study involves the development of guar gum-pectin-based solid self-nanoemulsifying drug delivery system (S-SNEDDS) containing curcumin (CCM) and fecal microbiota extract (FME) for the treatment of PCOS. The optimized S-SNEDDS containing FME and CCM was prepared by dissolving CCM (25 mg) in an isotropic mixture consisting of Labrafil M 1944 CS, Transcutol P, and Tween-80 and solidified using lactose monohydrate, aerosil-200, guar gum, and pectin (colon-targeted CCM solid self-nanoemulsifying drug delivery system [CCM-CT-S-SNEDDS]). Pharmacokinetic and pharmacodynamic evaluation was carried out on letrozole-induced female Wistar rats. The results of pharmacokinetic studies indicated about 13.11 and 23.48-fold increase in AUC of CCM-loaded colon-targeted S-SNEDDS without FME (CCM-CT-S-SNEDDS (WFME)) and CCM-loaded colon-targeted S-SNEDDS with FME [(CCM-CT-S-SNEDDS (FME)) as compared to unprocessed CCM. The pharmacodynamic study indicated excellent recovery/reversal in the rats treated with CCM-CT-S-SNEDDS low and high dose containing FME (group 13 and group 14) in a dose-dependent manner. The developed formulation showcasing its improved bioavailability, targeted action, and therapeutic activity in ameliorating PCOS can be utilized as an adjuvant therapy for developing a dosage form, scale-up, and technology transfer.

Mental illness is a hidden epidemic in modern science that has gradually spread worldwide. According to estimates from the World Health Organization (WHO), approximately 10% of the world's population suffers from various mental diseases each year. Worldwide, financial and health burdens on society are increasing annually. Therefore, understanding the different factors that can influence mental illness is required to formulate novel and effective treatments and interventions to combat mental illness. Gut microbiota, consisting of diverse microbial communities residing in the gastrointestinal tract, exert profound effects on the central nervous system through the gut-brain axis. The gut-brain axis serves as a conduit for bidirectional communication between the two systems, enabling the gut microbiota to affect emotional and cognitive functions. Dysbiosis, or an imbalance in the gut microbiota, is associated with an increased susceptibility to mental health disorders and psychiatric illnesses. Gut microbiota is one of the most diverse and abundant groups of microbes that have been found to interact with the central nervous system and play important physiological functions in the human gut, thus greatly affecting the development of mental illnesses. The interaction between gut microbiota and mental health-related illnesses is a multifaceted and promising field of study. This review explores the mechanisms by which gut microbiota influences mental health, encompassing the modulation of neurotransmitter production, neuroinflammation, and integrity of the gut barrier. In addition, it emphasizes a thorough understanding of how the gut microbiome affects various psychiatric conditions.

SUMMARYClostridioides difficile infection (CDI) is one of the major issues in nosocomial infections. This bacterium is constantly evolving and poses complex challenges for clinicians, often encountered in real-life scenarios. In the face of CDI, we are increasingly equipped with new therapeutic strategies, such as monoclonal antibodies and live biotherapeutic products, which need to be thoroughly understood to fully harness their benefits. Moreover, interesting options are currently under study for the future, including bacteriophages, vaccines, and antibiotic inhibitors. Surveillance and prevention strategies continue to play a pivotal role in limiting the spread of the infection. In this review, we aim to provide the reader with a comprehensive overview of epidemiological aspects, predisposing factors, clinical manifestations, diagnostic tools, and current and future prophylactic and therapeutic options for C. difficile infection.

SUMMARYGiven the importance of gut microbial homeostasis in maintaining health, there has been considerable interest in developing innovative therapeutic strategies for restoring gut microbiota. One such approach, fecal microbiota transplantation (FMT), is the main "whole gut microbiome replacement" strategy and has been integrated into clinical practice guidelines for treating recurrent Clostridioides difficile infection (rCDI). Furthermore, the potential application of FMT in other indications such as inflammatory bowel disease (IBD), metabolic syndrome, and solid tumor malignancies is an area of intense interest and active research. However, the complex and variable nature of FMT makes it challenging to address its precise functionality and to assess clinical efficacy and safety in different disease contexts. In this review, we outline clinical applications, efficacy, durability, and safety of FMT and provide a comprehensive assessment of its procedural and administration aspects. The clinical applications of FMT in children and cancer immunotherapy are also described. We focus on data from human studies in IBD in contrast with rCDI to delineate the putative mechanisms of this treatment in IBD as a model, including colonization resistance and functional restoration through bacterial engraftment, modulating effects of virome/phageome, gut metabolome and host interactions, and immunoregulatory actions of FMT. Furthermore, we comprehensively review omics technologies, metagenomic approaches, and bioinformatics pipelines to characterize complex microbial communities and discuss their limitations. FMT regulatory challenges, ethical considerations, and pharmacomicrobiomics are also highlighted to shed light on future development of tailored microbiome-based therapeutics.

Acute GVHD (aGVHD) is a major complication of allogeneic hematopoietic cell transplantation (alloHCT) associated with gut microbiota disruptions. However, whether therapeutic microbiota modulation prevents aGVHD is unknown. We conducted a randomized, placebo-controlled trial of third-party fecal microbiota transplantation (FMT) administered at the peak of microbiota injury in 100 patients with acute myeloid leukemia receiving induction chemotherapy and alloHCT recipients. Despite improvements in microbiome diversity, expansion of commensals, and shrinkage of potential pathogens, aGVHD occurred more frequently after FMT than placebo. Although this unexpected finding could be explained by clinical differences between the two arms, we asked whether a microbiota explanation might be also present. To this end, we performed multi-omics analysis of preintervention and postintervention gut microbiome and serum metabolome. We found that postintervention expansion of Faecalibacterium, a commensal genus with gut-protective and anti-inflammatory properties under homeostatic conditions, predicted a higher risk for aGVHD. Faecalibacterium expansion occurred predominantly after FMT and was due to engraftment of unique donor taxa, suggesting that donor Faecalibacterium-derived antigens might have stimulated allogeneic immune cells. Faecalibacterium and ursodeoxycholic acid (an anti-inflammatory secondary bile acid) were negatively correlated, offering an alternative mechanistic explanation. In conclusion, we demonstrate context dependence of microbiota effects where a normally beneficial bacteria may become detrimental in disease. While FMT is a broad, community-level intervention, it may need precision engineering in ecologically complex settings where multiple perturbations (e.g., antibiotics, intestinal damage, alloimmunity) are concurrently in effect.

Post-FMT expansion of Faecalibacterium, associated with donor microbiota engraftment, predicted a higher risk for aGVHD in alloHCT recipients. Although Faecalibacterium is a commensal genus with gut-protective and anti-inflammatory properties under homeostatic conditions, our findings suggest that it may become pathogenic in the setting of FMT after alloHCT. Our results support a future trial with precision engineering of the FMT product used as GVHD prophylaxis after alloHCT.

Clostridioides difficile infection (CDI) is an intestinal infection that causes morbidity and mortality and places significant burden and cost on the healthcare system, especially in recurrent cases. Antibiotic overuse is well recognized as the leading cause of CDI in high-risk patients, and studies have demonstrated that even short-term antibiotic exposure can cause a large and persistent disturbance to human colonic microbiota. The recovery and sustainability of the gut microbiome after dysbiosis have been associated with fewer CDI recurrences. Fecal microbiota transplantation (FMT) refers to the procedure in which human donor stool is processed and transplanted to a patient with CDI. It has been historically used in patients with pseudomembranous colitis even before the discovery of Clostridioides difficile. More recent research supports the use of FMT as part of the standard therapy of recurrent CDI. This article will be an in-depth review of five microbiome therapeutic products that are either under investigation or currently commercially available: Rebyota (fecal microbiota, live-jslm, formerly RBX2660), Vowst (fecal microbiota spores, live-brpk, formerly SER109), VE303, CP101, and RBX7455. Included in this review is a comparison of the products' composition and dosage forms, available safety and efficacy data, and investigational status.

Fecal microbiota transplants can be administered orally in encapsulated form or require invasive procedures to administer liquid formulations. There is a need for an oral liquid formulation of fecal microbiota for patients who are unable to swallow capsules, especially if they require multiple, repeated administrations.

These studies were conducted to develop a protocol to manufacture an organoleptically acceptable powdered fecal microbiota formulation that can be suspended in a liquid carrier and used for fecal microbiota transplantation.

Several processing steps were investigated, including extra washes of microbiota prior to lyophilization and an addition of a flavoring agent. The viability of bacteria in the transplant formulation was tested using live/dead microscopy staining and engraftment into antibiotic-treated mice. After development of a clinical protocol for suspension of the powdered microbiota, the new formulation was tested in three elderly patients with recurrent Clostridioides difficile infections and who have difficulties in swallowing capsules. Changes in the microbial community structure in one of the patients were characterized using 16S rRNA gene profiling and engraftment analysis.

The processing steps used to produce an organoleptically acceptable suspension of powdered fecal microbiota did not result in loss of its viability. The powder could be easily suspended in a liquid carrier. The use of the new formulation was associated with abrogation of the cycle of C. difficile infection recurrences in the three patients.

We developed a novel organoleptically acceptable liquid formulation of fecal microbiota that is suitable for use in clinical trials for patients with difficulties in swallowing capsules.

Microbiota therapeutics that transplant faecal material from healthy donors to people with mild-to-moderate ulcerative colitis have shown the potential to induce remission in about 30% of participants in small, phase 2 clinical trials. Despite this substantial achievement, the field needs to leverage the insights gained from these trials and progress towards phase 3 clinical trials and drug approval, while identifying the distinct clinical niche for this new therapeutic modality within inflammatory bowel disease (IBD) therapeutics. We describe the lessons that can be learned from past studies of microbiota therapeutics, from full spectrum donor stool to defined products manufactured in vitro. We explore the actionable insights these lessons provide on the design of near-term studies and future trajectories for the integration of microbiota therapeutics in the treatment of IBD. If successful, microbiota therapeutics will provide a powerful orthogonal approach (complementing or in combination with existing immunomodulatory drugs) to raise the therapeutic ceiling for the many non-responders and partial responders within the IBD patient population.

The gut microbiome is acknowledged as a key determinant of human health, and technological progress in the past two decades has enabled the deciphering of its composition and functions and its role in human disorders. Therefore, manipulation of the gut microbiome has emerged as a promising therapeutic option for communicable and non-communicable disorders. Full exploitation of current therapeutic microbiome modulators (including probiotics, prebiotics, and faecal microbiota transplantation) is hindered by several factors, including poor precision, regulatory and safety issues, and the impossibility of providing reproducible and targeted treatments. Artificial microbiota therapeutics (which include a wide range of products, such as microbiota consortia, bacteriophages, bacterial metabolites, and engineered probiotics) have appeared as an evolution of current microbiota modulators, as they promise safe and reproducible effects, with variable levels of precision via different pathways. We describe the landscape of artificial microbiome therapeutics, from those already on the market to those still in the pipeline, and outline the major challenges for positioning these therapeutics in clinical practice.

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.

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.

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.

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.

Clostridioides difficile infection (CDI) is one of the most common healthcare-associated infections and one of the leading causes of morbidity and mortality in hospitalized patients in the world. Although several antibiotics effectively treat CDI, some individuals may not respond to these drugs and may be cured by transplanting stool from healthy donors. FMT has demonstrated extraordinary cure rates for the cure of CDI recurrences.Moreover, FMT has also been investigated in other disorders associated with the alteration of gut microbiota, such as inflammatory bowel disease (IBD), where the alterations of the gut microbiota ecology have been theorized to play a causative role. Although FMT is currently not recommended to cure IBD patients in clinical practice, several studies have been recently carried out with the ultimate goal to search new therapeutic options to patients.This review summarizes data on the use of FMT for the treatment of both CDI and IBD, with a special attention to highlight studies conducted in European countries.