European consensus conference on faecal microbiota transplantation in clinical practice

Fecal microbiota transplantation from a healthy pouch donor for chronic pouchitis: a proof-of-concept study

Chronic pouchitis is a common complication after ileal pouch-anal anastomosis (IPAA) with limited treatment options. In this case series, we aimed to investigate clinical and microbiome changes, as well as adverse events, associated with using fecal microbiota transplantation (FMT) from a donor with a normal functioning IPAA to induce remission in patients with chronic pouchitis. Methods The study was a case-series including a 4-week intervention period and 12-month follow-up. Patients with chronic pouchitis who met the inclusion criteria were recruited from the Department of Gastrointestinal Surgery at Aalborg University Hospital, Denmark. Participants received FMT derived from a donor with a normal functioning IPAA. Treatment was administered by enema daily for two weeks, then every other day for two more weeks. Disease severity and quality of life (QoL) were accessed at baseline and 30-day follow-up. Clinical remission was defined as Pouchitis Disease Activity Index (PDAI) <7. Fecal samples from participants, healthy donors, and the IPAA donor were analyzed using shotgun metagenomic sequencing. Results Three patients with chronic pouchitis were included and completed the treatment protocol and follow-up visits. At the 30-day follow-up, all participants achieved clinical remission with reduced endoscopic inflammation. The median total PDAI score decreased from 8 (range 10-8) at baseline to 6 (range 6-5) at 30 days. Two participants reported improved QoL, while one reported no change. Few mild, self-limited adverse events were reported by all participants during treatment, with no serious events. Principal component analysis of fecal samples distinguished two clusters: healthy donors and the IPAA donor, with participant samples forming a separate cluster Conclusion We observed that all participants achieved clinical remission with reduced endoscopic inflammation following a 4-week FMT intervention. Adverse events were mild and self-limited. Metagenomic analysis revealed distinct microbiome clusters between IPAA donor and recipients, both of which differed from those of healthy donors.

Fecal microbiota transplantation modulates myeloid-derived suppressor cells and attenuates renal fibrosis in a murine model

BACKGROUND

Renal fibrosis is a hallmark of progressive chronic kidney disease (CKD), with emerging evidence linking gut microbiota dysbiosis to disease progression. Myeloid-derived suppressor cells (MDSCs) have demonstrated renoprotective effects, yet the impact of fecal microbiota transplantation (FMT) on MDSC-mediated modulation of renal fibrosis remains unclear.

METHODS

C57BL/6J mice underwent unilateral ureteral obstruction (UUO) to induce renal fibrosis, followed by FMT administration via gavage. Flow cytometry was used to quantify granulocytic (G-MDSCs) and monocytic (M-MDSCs) MDSC populations in peripheral blood, kidney, and spleen. To elucidate the role of MDSCs in FMT-mediated effects, MDSCs were depleted or adoptively transferred in vivo. Renal fibrosis severity and inflammatory cytokine expression were subsequently analyzed.

RESULTS

FMT altered MDSC distribution, increasing M-MDSC accumulation in the blood and kidney. This was associated with downregulation of proinflammatory cytokines and attenuation of renal fibrosis. Adoptive MDSC transfer similarly produced anti-inflammatory and antifibrotic effects, reinforcing their therapeutic role in FMT-mediated renal protection.

CONCLUSIONS

FMT enhances M-MDSC-mediated immunomodulation, reducing inflammation and renal fibrosis in UUO-induced CKD. These findings suggest a potential therapeutic strategy targeting the gut-kidney axis in CKD management.

Gut microbiota modulation via fecal microbiota transplantation mitigates hyperoxaluria and calcium oxalate crystal depositions induced by high oxalate diet

Hyperoxaluria, including primary and secondary hyperoxaluria, is a disorder characterized by increased urinary oxalate excretion and could lead to recurrent calcium oxalate kidney stones, nephrocalcinosis and eventually end stage renal disease. For secondary hyperoxaluria, high dietary oxalate (HDOx) or its precursors intake is a key reason. Recently, accumulated studies highlight the important role of gut microbiota in the regulation of oxalate homeostasis. However, the underlying mechanisms involving gut microbiota and metabolite disruptions in secondary hyperoxaluria remain poorly understood. Here, we investigated the therapeutic efficacy of fecal microbiota transplantation (FMT) sourced from healthy rats fed with standard pellet diet against urinary oxalate excretion, renal damage and calcium oxalate (CaOx) crystal depositions via using hyperoxaluria rat models. We observed dose-dependent increases in urinary oxalate excretion and CaOx crystal depositions due to hyperoxaluria, accompanied by significant reductions in gut microbiota diversity characterized by shifts in Ruminococcaceae_UCG-014 and Parasutterella composition. Metabolomic analysis validated these findings, revealing substantial decreases in key metabolites associated with these microbial groups. Transplanting microbes from healthy rats effectively reduced HDOx-induced urinary oxalate excretion and CaOx crystal depositions meanwhile restoring Ruminococcaceae_UCG-014 and Parasutterella populations and their associated metabolites. Furthermore, FMT treatment could significantly decrease the urinary oxalate excretion and CaOx crystal depositions in rat kidneys via, at least in part, upregulating the expressions of intestinal barrier proteins and oxalate transporters in the intestine. In conclusion, our study emphasizes the effectiveness of FMT in countering HDOx-induced hyperoxaluria by restoring gut microbiota and related metabolites. These findings provide insights on the complex connection between secondary hyperoxaluria caused by high dietary oxalate and disruptions in gut microbiota, offering promising avenues for targeted therapeutic strategies.

Dysregulation of gut microbiota stimulates NETs-driven HCC intrahepatic metastasis: therapeutic implications of healthy faecal microbiota transplantation

The stringent regulation of intrahepatic metastases is essential for improving survival outcomes in patients with hepatocellular carcinoma (HCC). This study investigated the impact of gut microbiota on intrahepatic metastasis of HCC and evaluated the therapeutic potential of healthy fecal microbiota transplantation (FMT). Dysregulation of the gut microbiota, characterized by a significant reduction in the abundance of beneficial bacteria, such as Anaerotruncus colihominis and Dysosmobacter welbionis, was observed in patients with intrahepatic metastatic HCC. A human flora-associated (HFA) intrahepatic metastatic HCC mouse model was successfully established through consecutive 4 weeks of human-mouse FMT. Dysregulation of gut microbiota promoted intrahepatic metastasis in the mouse model, primarily by enhancing neutrophil-mediated inflammatory responses and lead to excessive formation of neutrophil extracellular traps (NETs). Consequently, it promoted tumor vascular growth and tissue necrosis, resulting in intrahepatic metastasis of HCC. Notably, FMT from healthy donors mitigated these pathological processes. This study elucidated the role and mechanism of dysregulated gut microbiota in promoting intrahepatic metastasis of HCC. Healthy FMT emerges as a promising novel therapeutic strategy for preventing and treating intrahepatic metastasis of HCC.

Virome drift in ulcerative colitis patients: faecal microbiota transplantation results in minimal phage engraftment dominated by microviruses

Ulcerative colitis (UC) is an inflammatory bowel disease characterized by recurrent colonic inflammation. Standard treatments focus on controlling inflammation but remain ineffective for one-third of patients. This underscores the need for alternative approaches, such as fecal microbiota transplantation (FMT), which transfers healthy donor microbiota to patients. The role of viruses in this process, however, remains underexplored. To address this, we analyzed the gut virome using metagenomic sequencing of enriched viral particles from 320 longitudinal fecal samples of 44 patients enrolled in the RESTORE-UC FMT trial. Patients were treated with FMTs from healthy donors (allogenic, treatment) or themselves (autologous, control). We found that colonic inflammation, both its presence and location, had a greater impact on the gut virome than FMT itself. In autologous FMT patients, the virome was unstable and showed rapid divergence over time, a phenomenon we termed virome drift. In allogenic FMT patients, the virome temporarily shifted toward the healthy donor, lasting up to 5 weeks and primarily driven by microviruses. Notably, two distinct virome configurations were identified and linked to either healthy donors or patients. In conclusion, inflammation strongly affects the gut virome in UC patients, which may lead to instability and obstruct the engraftment of allogeneic FMT.

To explore the potential combined treatment strategy for colorectal cancer: Inhibition of cancer stem cells and enhancement of intestinal immune microenvironment

BACKGROUND

The antibiotic salinomycin, a well-known cancer stem cell inhibitor, may impact the diversity of the intestinal microbiota in colorectal cancer (CRC) mice, which plays a pivotal role in shaping the immune system. This study explores the anti-cancer effects and mechanisms of combining salinomycin and fecal microbiota transplantation (FMT) in treating CRC.

METHODS

FMT was given via enema, while salinomycin was injected intraperitoneally into the CRC mouse model induced by azoxymethane/dextran sodium sulfate.

RESULTS

In CRC mice, a large number of LGR5-labeled cancer stem cells and severe disturbances in the intestinal microbiota were observed. Interestingly, salinomycin inhibited the proliferation of cancer stem cells without exacerbating the microbial disorder as expected. In comparison to salinomycin treatment, the combination of salinomycin and FMT significantly improved pathological damage and restored intestinal microbial diversity, which is responsible for shaping the anti-cancer immune microenvironment. The supplementation of FMT significantly increased the levels of propionic acid and butyric acid while also promoting the infiltration of CD8+ T cells and Ly6G+ neutrophils, as well as reducing F4/80+ macrophage recruitment. Notably, cytokines that were not impacted by salinomycin exhibited robust reactions to alterations in the gut microbiota. These included pro-inflammatory factors (IL6, IL12b, IL17, and IL22), chemokine-like protein OPN, and immunosuppressive factor PD-L1.

CONCLUSIONS

Salinomycin plays the role of "eliminating pathogenic qi," targeting cancer stem cells; FMT plays the role of "strengthening vital qi," reversing the intestinal microbiota disorder and enhancing anti-cancer immunity. They have a synergistic effect on the development of CRC.

Exploring the gut microbiome’s influence on cancer-associated anemia: Mechanisms, clinical challenges, and innovative therapies

BACKGROUND

Anemia is a prevalent and challenging complication in patients with hematologic and solid malignancies, which stems from the direct effects of malignancy, treatment-induced toxicities, and systemic inflammation. It affects patients’ survival, functional status, and quality of life profoundly. Recent literature has highlighted the emerging role of the gut microbiome in the pathogenesis of cancer-associated anemia. The gut microbiota, through its intricate interplay with iron metabolism, inflammatory pathways, and immune modulation, may either exacerbate or ameliorate anemia depending on its composition, and functional integrity. Dysbiosis, characterized by disruption in the gut microbial ecosystem, is very common in cancer patients. This microbial imbalance is implicated in anemia causation through diminished iron absorption, persistent low-grade inflammation, and suppression of erythropoiesis.

AIM

To consolidate current evidence regarding the interplay between gut microbiome and anemia in the setting of malignancies. It aims to provide a detailed exploration of the mechanistic links between dysbiosis and anemia, identifies unique challenges associated with various cancer types, and evaluates the efficacy of microbiome-focused therapies. Through this integrative approach, the review seeks to establish a foundation for innovative clinical strategies aimed at mitigating anemia and improving patient outcomes in oncology.

METHODS

A literature search was performed using multiple databases, including Google Scholar, PubMed, Scopus, and Web of Science, using a combination of keywords and Boolean operators to refine results. Keywords included “cancer-associated anemia”, “gut microbiome”, “intestinal microbiota”, “iron metabolism”, “gut dysbiosis”, “short-chain fatty acids”, “hematopoiesis”, “probiotics”, “prebiotics”, and “fecal microbiota transplantation”. Articles published in English between 2000 and December 2024 were included, with a focus on contemporary and relevant findings.

RESULTS

Therapeutic strategies aimed at restoration of gut microbial homeostasis, such as probiotics, prebiotics, dietary interventions, and fecal microbiota transplantation (FMT), can inhibit anemia-causing pathways by enhancing microbial diversity, suppressing detrimental flora, reducing systemic inflammation and optimizing nutrient absorption.

CONCLUSION

Gut dysbiosis causes anemia and impairs response to chemotherapy in cancer patients. Microbiome-centered interventions, such as probiotics, prebiotics, dietary modifications, and FMT, have shown efficacy in restoring microbial balance, reducing inflammation, and enhancing nutrient bioavailability. Emerging approaches, including engineered probiotics and bacteriophage therapies, are promising precision-based, customizable solutions for various microbiome compositions and imbalances. Future research should focus on integrating microbiome-targeted strategies with established anemia therapies.

Optimizing Therapeutic Potential of Fecal Transplant in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic inflammatory condition of the gastrointestinal tract influenced by genetic, environmental, immune, and microbial factors. Reduced gut microbial diversity and elevated proinflammatory bacteria levels in IBD disrupt mucosal immunity, barrier function, and inflammatory pathways. Fecal microbiota transplantation (FMT) is a potential therapy to restore microbial balance. Studies suggest that FMT may induce remission in mild-to-moderate ulcerative colitis but show limited efficacy in Crohn's disease and pouchitis. Donor microbiota colonization correlates with remission, but varied study designs challenge findings. Further research is required to standardize FMT protocols, optimize donor selection, and ensure long-term safety.

Revisiting the characteristics of nanomaterials, composites, hybrid and functionalized materials in medical microbiology

Unlike traditional materials designed to form large structures, many modern materials are presented in the form of powders resulting from a molecular level control of their composition and structure, making possible the miniaturization and fine-tuning of their properties to act in cellular dimensions with customized tasks. Several new materials for biomedical and microbiology applications appear every year. Although many of them are called nanomaterials, there may be a more precise description or classification. In this work, we review and detail the structural classification of nanometric, functionalized, hybrid and composite materials, mainly based on descriptions given by the International Union of Pure and Applied Chemistry (IUPAC). Besides we included smart and multifunctional materials, cassification based on performance. The second section shows how these materials are used in the area of medical microbiology, grouping these applications into barriers for microorganisms on surfaces, disinfectants in clinical practice, targeting of pathogens, detectors of microorganisms or their metabolites, and also as substrates to stabilize, transport, or nourish beneficial microorganisms. Finally, we will discuss some evidence that indicates the environmental risk and bacterial resistance alerts that should be taken into account with the use of these advanced powder materials.

Receptor-targeted Lactococcus lactis mitigate Clostridioides difficile infection

Engineered bacteria play an important role in colorectal disease. Lactococcus lactis (L. lactis) can inhibit Clostridioides difficile (C. difficile) by producing antimicrobial peptide nisin. However, its insufficient nisin production levels, lack of targeted in vivo release and weak colonization ability may limit its therapeutic efficacy against C. difficile infection (CDI). In this study, we engineered a strain of L. lactis with high adherence and therapeutic potential (Lla+) by expressing C. difficile adhesion protein Cwp8 on the surface of a L. lactis strain with high nisin yield (4019 to 4028 IU/ml). The adhesion effect of Lla+ was increased by 1.3-fold compared to the wild type L. lactis in the HT-29 cell model. We created the lipid membrane-coated L. lactis (LCL) by encapsulating Lla+ with the ROS-responsive lipid membrane. LCL exhibited targeted release of nisin payload in response to H2O2, lipopolysaccharide and C. difficile in vitro, as well as in various mouse models of intestinal inflammation in vivo. The therapeutic effect of LCL against CDI was substantial, reducing C. difficile survival by 60 % compared to the untreated control. In the treatment of recurrent CDI (rCDI), LCL outperformed the drug fidaxomicin, the first-line treatment for rCDI recommended by Infectious Diseases Society of America (IDSA), decreasing C. difficile survival by 48 % and lowering the levels of toxins TcdA and TcdB by 57.1 % and 65 %, respectively. These results suggested that the presented the encapsulation approach could serve as a delivery platform to target inflamed intestines and expand the application of probiotics as pharmaceuticals.

Evaluation of the effects of different formulations of protectants on the preservation of the microbiota in fecal microbiota transplantation

BACKGROUND

With the increasing indications for fecal microbiota transplantation for the treatment of diseases, there is a growing demand for the preparation of frozen or lyophilized fecal microbiota products that are viable and can stably colonize the recipient. The addition of protective agents plays an important role in the preparation. However, there has been no systematic evaluation of the protective agents used in fecal microbiota sample transplantation preparation for transplantation.

METHODS

We were used the donor bacterial flora containing 10 different formulations of protective agents were frozen, lyophilized, and stored. Plate counting, CCK8 assay, flow cytometry after LIVE/DEAD staining, and fluorescence intensity were used to assess viable bacteria in vitro. In addition, the donor bacterial flora samples containing different formulations protective agents were transplanted into antibiotic-treated SPF mice, with 3 mice in each group and a total of 5 groups. Fecal samples were collected for metagenomic sequencing to observe the colonization of the bacterial flora in the recipient mice.

RESULTS

The preliminary screening results showed that the survival rate of bacteria in the 5% trehalose (T) groups, and 5% sucrose, 5% inulin, and 1% cysteine hydrochloride (SI) groups was slightly higher than that in the other groups. SI groups tended to be more protective against anaerobes than T groups. The donor gut microbiota containing the SI groups protective agent exhibited the best colonization of the recipient mice. The protective effects of different formulations of protective agents on the colonized probiotic strains and the metabolic function of the bacterial flora in recipient mice were found to be species specific.

CONCLUSIONS

SI groups can not only better protect the activity of anaerobic bacteria in the intestine, but also effectively promote the effective colonization of donor intestinal bacteria in the recipient mice, and the effect of frozen storage method is less, and can be used at the same time as frozen and freeze-dried preparation. It can be used as a reference for the selection of protective agents in the preparation of fecal microbiota transplantation samples.

Fecal microbiota transplantation for hypertension: an exploratory, multicenter, randomized, blinded, placebo-controlled trial

BACKGROUND

On the basis of the contribution of the gut microbiota to hypertension development, a novel strategy involving fecal microbiota transplantation (FMT) has been proposed to treat hypertension, but its efficacy has not been investigated in the clinic.

METHODS

In a randomized, blinded, placebo-controlled clinical trial (2021/03-2021/12, ClinicalTrials.gov, NCT04406129), hypertensive patients were recruited from seven centers in China, and received FMT or placebo capsules orally at three visits. The patients were randomized at a 1:1 ratio in blocks of four and stratified by center by an independent statistician. The intention-to-treat principle was implemented, as all randomized participants who received at least one intervention were included. The primary outcome was the decrease in office systolic blood pressure (SBP) from baseline to the day 30 visit. Adverse events (AEs) were recorded through the 3-month follow-up to assess safety measures. Alterations in BP, the fecal microbiome, and the plasma metabolome were assessed via exploratory analyses.

RESULTS

This study included 124 patients (mean age 43 years, 73.4% men) who received FMT (n = 63) or placebo (n = 61) capsules. The numbers of participants who experienced AEs (13 (20.6%) vs. 9 (14.8%), p = 0.39) and the primary outcome (6.28 (11.83) vs. 5.77 (10.06) mmHg, p = 0.62) were comparable between the groups. The FMT group presented a decrease in SBP after 1 week of FMT, with a between-arm difference of - 4.34 (95% CI, - 8.1 to - 0.58; p = 0.024) mmHg, but this difference did not persist even after repeated intervention. After FMT, shifts in microbial richness and structure were identified and the abundance of the phyla Firmicutes and Bacteroidetes was altered. Decreases in the abundances of Eggerthella lenta, Erysipelatoclostridium ramosum, Anaerostipes hadrus, Gemella haemolysans, and Streptococcus vestibularis and increases in the abundances of Parabacteroides merdae, Prevotella copri, Bacteroides galacturonicus, Eubacterium sp. CAG 180, Desulfovibrio piger, Megamonas hypermegale, Collinsella stercoris, Coprococcus catus, and Allisonella histaminiformans were identified and correlated with office SBP. Those species were also correlated with responding and inversely office SBP-associated metabolites including tyrosine, glutamine, aspartate, phenylalanine, methionine, serine, sarcosine, and/or asparagine.

CONCLUSIONS

Safety but unsustainable BP reduction was observed in the first trial of the effects of FMT on hypertension. Additional intervention studies on specific microbes with metabolite-targeting and BP-modulating features are needed. Video Abstract.

Links between short-chain fatty acids and osteoarthritis from pathology to clinic via gut-joint axis

Short-chain fatty acids (SCFAs), the primary metabolites produced by the microbial fermentation of dietary fibers in the gut, have a key role in protecting gut health. Increasing evidence indicates SCFAs can exert effects on distant tissues and organs beyond the gut via blood circulation. Osteoarthritis (OA) is a chronic inflammatory joint disease that severely diminishes the physical function and quality of life. However, effective clinical treatments for OA remain elusive. Recent studies have shown that SCFAs can exert beneficial effects on damaged joints in OA. SCFAs can mitigate OA progression by preserving intestinal barrier function and maintaining the integrity of cartilage and subchondral bone, suggesting that they have substantial potential to be the adjunctive treatment strategy for OA. This review described the SCFAs in the human body and their cellular signaling mechanism, and summarized the multiple effects of SCFAs (especially butyrate, propionate, and acetate) on the prevention and treatment of OA by regulating the gut-joint axis, providing novel insights into their promising clinical applications.

Racial and Ethnic Disparities in NAFLD: Harnessing Epigenetic and Gut Microbiota Pathways for Targeted Therapeutic Approaches

Nonalcoholic fatty liver disease (NAFLD) is a growing global health concern, impacting approximately 32.4% of the worldwide population. As a disease linked to metabolic dysfunction, NAFLD continues to rise alongside global increases in obesity, type 2 diabetes mellitus (T2DM), and metabolic syndrome. There is considerable evidence indicating that NAFLD disproportionately affects racial, ethnic, and minority groups, although the exact reasons for these disparities remain elusive. Contributing factors to this disease may include socioeconomic status, cultural influences, stress, genetic factors, and lifestyle choices. Emerging evidence suggests that these causal factors could influence epigenetic mechanisms, particularly DNA methylation and histone modifications, as well as the composition and diversity of gut microbiota. Nevertheless, there is a scarcity of research that comprehensively examines the interplay between epigenetic changes and gut microbiome variations in relation to NAFLD disparities across different racial and ethnic populations globally. This paper intends to (i) explore the connections between NAFLD, ethnic disparities, gut microbiota composition, and epigenetic alterations, while reviewing pertinent studies that illustrate how these factors contribute to health inequities among various ethnic groups impacted by this disease; (ii) explore potential therapeutic targets and biomarkers to advance the management of NAFLD; and (iii) provide insights to enhance our understanding of the mechanisms associated with this disease, thereby promoting further research in this field. Advancements in this area are anticipated to enhance our understanding of disease susceptibilities in at-risk groups and to provide new therapeutic options for NAFLD and its associated complications.

Inflammatory bowel disease and neuropsychiatric disorders: Mechanisms and emerging therapeutics targeting the microbiota-gut-brain axis

Crohn's disease (CD) and ulcerative colitis (UC) are the two major entities of inflammatory bowel disease (IBD). These disorders are known for their relapsing disease course and severe gastrointestinal symptoms including pain, diarrhoea and bloody stool. Accumulating evidence suggests that IBD is not only restricted to the gastrointestinal tract and that disease processes are able to reach distant organs including the brain. In fact, up to 35 % of IBD patients also suffer from neuropsychiatric disorders such as generalized anxiety disorder and major depressive disorder. Emerging research in this area indicates that in many cases these neuropsychiatric disorders are a secondary condition as a consequence of the disturbed communication between the gut and the brain via the microbiota-gut-brain axis. In this review, we summarise the current knowledge on IBD-associated neuropsychiatric disorders. We examine the role of different pathways of the microbiota-gut-brain axis in the development of CNS disorders highlighting altered neural, immunological, humoral and microbial communication. Finally, we discuss emerging therapies targeting the microbiota-gut-brain axis to alleviate IBD and neuropsychiatric symptoms including faecal microbiota transplantation, psychobiotics, microbial metabolites and vagus nerve stimulation.

Fecal microbiota transplantation against moderate-to-severe atopic dermatitis: A randomized, double-blind controlled explorer trial

BACKGROUND

Fecal microbiota transplantation (FMT) is a novel treatment for inflammatory diseases. Herein, we assess its safety, efficacy, and immunological impact in patients with moderate-to-severe atopic dermatitis (AD).

METHODS

In this randomized, double-blind, placebo-controlled clinical trial, we performed the efficacy and safety assessment of FMT for moderate-to-severe adult patients with AD. All patients received FMT or placebo once a week for 3 weeks, in addition to their standard background treatments. Patients underwent disease severity assessments at weeks 0, 1, 2, 4, 8, 12, and 16, and blood and fecal samples were collected for immunologic analysis and metagenomic shotgun sequencing, respectively. Safety was monitored throughout the trial.

RESULTS

Improvements in eczema area and severity index (EASI) scores and percentage of patients achieving EASI 50 (50% reduction in EASI score) were greater in patients treated with FMT than in placebo-treated patients. No serious adverse reactions occurred during the trial. FMT treatment decreased the Th2 and Th17 cell proportions among the peripheral blood mononuclear cells, and the levels of TNF-α, and total IgE in serum. By contrast, the expression levels of IL-12p70 and perforin on NK cells were increased. Moreover, FMT altered the abundance of species and functional pathways of the gut microbiota in the patients, especially the abundance of Megamonas funiformis and the pathway for 1,4-dihydroxy-6-naphthoate biosynthesis II.

CONCLUSION

FMT was a safe and effective therapy in moderate-to-severe adult patients with AD; the treatment changed the gut microbiota compositions and functions.

Translational strategies for oral delivery of faecal microbiota transplantation

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.

Fecal Microbiota Transplantation Using Donor Stool Obtained from Exercised Mice Suppresses Colonic Tumor Development Induced by Azoxymethane in High-Fat Diet-Induced Obese Mice

The gut microbiota plays an important role in the development of colorectal tumors. However, the underlying mechanisms remain unclear. In this study, we examined the effects of fecal microbiota transplantation (FMT) on azoxymethane (AOM)-induced colorectal tumors in obese mice. We divided the study subjects into the following five groups: high-fat diet (HFD), normal diet (ND), ND+exercise (Ex), HFD+FMT from ND-alone donor (HFD+FMT(ND alone)), and HFD+FMT from ND+Ex donor (HFD+FMT(ND+Ex)). The Ex group performed treadmill exercise for 15 weeks. Thereafter, fecal and colonic mucus samples were extracted for microbiome analysis. The deoxyribonucleic acid sample was collected from the feces and colonic mucosa, and V3-V4 amplicon sequencing analysis of the 16S rRNA gene was performed using MiSeq. The number of polyps was significantly lower in the ND (6.0 ± 1.6) and ND+Ex (1.8 ± 1.3) groups than in the HFD group (11.4 ± 1.5). The ND+Ex group had significantly fewer polyps than the ND group. The HFD+FMT(ND alone) (5.2 ± 0.8) and HFD+FMT(ND+Ex) (2.8 ± 2.6) groups also had significantly fewer polyps than the HFD group. The IL-15 mRNA levels in the colonic tissues were significantly higher in the HFD+FMT(ND alone) group than in the ND group. Fecal ω-muricholic acid concentrations were significantly higher in the HFD+FMT(ND alone) group than in the ND group and in the HFD+FMT(ND+Ex) group than in the ND+Ex group. The ND, ND+Ex, HFD+FMT(ND alone), and HFD+FMT(ND+Ex) groups had a significantly higher abundance of Lacyobacillaceae than the HFD group. In the FMT group, Erysipelotrichaceae and Tannerellaceae were significantly less abundant. Compared with the HFD group, the ND, ND+Ex, HFD+FMT(ND alone), and HFD+FMT(ND+Ex) groups had a significantly higher abundance of Muribaculaceae and a significantly higher abundance of Lactobacillaceae and Rikenellaceae in common among the ND and ND+Ex groups. The common and significantly less common species were Bacteroidaceae in the FMT group and Lactobacillaceae and Rikenellaceae in the ND alone and ND+Ex groups. Bacteroidaceae and Lachnospiraceae were significantly less common in the FMT group. We found that FMT inhibited AOM-induced colorectal tumorigenesis in obese mice. Furthermore, the fecal concentrations of short-chain fatty acids, bile acids, microbiota, and mucosa-associated microbiota differed between the FMT and diet/EX groups, suggesting that the inhibitory effect of FMT on colorectal tumorigenesis may be due to mechanisms different from those of ND alone and ND+Ex.

Transient colonization with Blastocystis spp. after transmission via fecal microbiota transplantation

BACKGROUND

The pathogenicity of Blastocystis spp. is still debated. Guidelines for feces donor screening differ in their advice to screen for Blastocystis spp., but when tested, its presence is a common reason for exclusion. Blastocystis spp. are correlated to increased bacterial alpha-diversity and distinct bacterial groups and therefore its presence may indicate favorable efficacy of fecal microbiota transplantation (FMT). The latest European consensus report no longer advices rejecting feces donors testing positive for Blastocystis spp. Only one paper has been published on human transmission of Blastocystis spp. via frozen FMT.

OBJECTIVE

To investigate the transmission and long-term effects of Blastocystis-positive FMT, prepared with fresh (i.e., unfrozen) feces.

METHODS

In a trial (NCT03074227) on FMT for refractory Irritable Bowel Syndrome (IBS), adolescents (age 16-20 years) received two administrations - at baseline and after 6 weeks - of fresh allogeneic FMT from a Blastocystis-positive donor via nasoduodenal tube. The follow-up was 48 weeks. Blastocystis spp. presence, viability and subtyping were determined using microscopy, culture, PCR and sequencing.

RESULTS

Three recipients received FMT from one donor colonized with Blastocystis subtype 3 (ST3). At baseline, two recipients were negative for Blastocystis spp. and one recipient carried ST2. Culturing revealed viable Blastocystis spp. in fresh donor feces but not in frozen samples. After FMT with fresh feces, the two prior-negative recipients tested positive for the donor's ST3 at 12 weeks, but had lost this subtype by week 24 and 48. The recipient initially colonized with ST2 remained colonized with ST2 and did not acquire ST3. Transient adverse events occurred, but did not differ from patients treated with Blastocystis-negative FMT. No FMT-related serious adverse events emerged.

CONCLUSION

We present the first long-term data on viable Blastocystis spp. transmission via fresh FMT in three cases. Transient colonization with Blastocystis spp. was observed, without serious FMT-related adverse events.

Study protocol: Fecal Microbiota Transplant combined with Atezolizumab/Bevacizumab in Patients with Hepatocellular Carcinoma who failed to achieve or maintain objective response to Atezolizumab/Bevacizumab - the FAB-HCC pilot study

BACKGROUND

The gut microbiota is often altered in chronic liver diseases and hepatocellular carcinoma (HCC), and increasing evidence suggests that it may influence response to cancer immunotherapy. Strategies to modulate the gut microbiome (i.e., fecal microbiota transplant (FMT)) may help to improve efficacy of immune checkpoint inhibitors (ICIs) or even overcome resistance to ICIs. Here, we describe the design and rationale of FAB-HCC, a single-center, single-arm, phase II pilot study to assess safety, feasibility, and efficacy of FMT from patients with HCC who responded to PD-(L)1-based immunotherapy or from healthy donors to patients with HCC who failed to achieve or maintain a response to atezolizumab plus bevacizumab.

METHODS

In this single-center, single-arm, phase II pilot study (ClinicalTrials.gov identifier: NCT05750030), we plan to include 12 patients with advanced HCC who failed to achieve or maintain a response to atezolizumab/bevacizumab. Patients will receive a single FMT via colonoscopy from donors with HCC who responded to PD-(L)1-based immunotherapy or from healthy individuals, followed by atezolizumab/bevacizumab every 3 weeks. The primary endpoint is safety, measured by incidence and severity of treatment-related adverse events. The main secondary endpoint is efficacy, as assessed by best radiological response according to RECISTv1.1 and mRECIST. Additional exploratory endpoints include data on the effect of FMT on recipient gut microbiota, as well as metagenomic analysis of stool samples, analyses of circulating immune cells and serum and stool proteomic, metabolomic and lipidomic signatures.

DISCUSSION

The results of this study will help to define the potential of FMT as add-on intervention in the systemic treatment of advanced HCC, with the potential to improve efficacy of immunotherapy or even overcome resistance.

TRIAL REGISTRATION

EudraCT Number: 2022-000234-42 Clinical trial registry & ID: ClinicalTrials.gov identifier: NCT05750030 (Registration date: 16.01.2023).

Microbiome Gut-Brain-Axis: Impact on Brain Development and Mental Health

The current discovery that the gut microbiome, which contains roughly 100 trillion microbes, affects health and disease has catalyzed a boom in multidisciplinary research efforts focused on understanding this relationship. Also, it is commonly demonstrated that the gut and the CNS are closely related in a bidirectional pathway. A balanced gut microbiome is essential for regular brain activities and emotional responses. On the other hand, the CNS regulates the majority of GI physiology. Any disruption in this bidirectional pathway led to a progression of health problems in both directions, neurological and gastrointestinal diseases. In this review, we hope to shed light on the complicated connections of the microbiome-gut-brain axis and the critical roles of gut microbiome in the early development of the brain in order to get a deeper knowledge of microbiome-mediated pathological conditions and management options through rebalancing of gut microbiome.

Recent Advances in Gut Microbiota in Psoriatic Arthritis

Psoriatic arthritis (PsA) is a chronic inflammatory disease characterized by joint inflammation and skin lesions. Recent research has underscored the critical role of gut microbiota-comprising bacteria, fungi, viruses, and archaea-in the pathogenesis and progression of PsA. This narrative review synthesizes the latest findings on the influence of gut microbiota on PsA, focusing on mechanisms such as immune modulation, microbial dysbiosis, the gut-joint axis, and its impact on treatment. Advances in high-throughput sequencing and metagenomics have revealed distinct microbial profiles associated with PsA. Studies show that individuals with PsA have a unique gut microbiota composition, differing significantly from healthy controls. Alterations in the abundance of specific bacterial taxa, including a decrease in beneficial bacteria and an increase in potentially pathogenic microbes, contribute to systemic inflammation by affecting the intestinal barrier and promoting immune responses. This review explores the impact of various factors on gut microbiota composition, including age, hygiene, comorbidities, and medication use. Additionally, it highlights the role of diet, probiotics, and fecal microbiota transplantation as promising strategies to modulate gut microbiota and alleviate PsA symptoms. The gut-skin-joint axis concept illustrates how gut microbiota influences not only gastrointestinal health but also skin and joint inflammation. Understanding the complex interplay between gut microbiota and PsA could lead to novel, microbiome-based therapeutic approaches. These insights offer hope for improved patient outcomes through targeted manipulation of the gut microbiota, enhancing both diagnosis and treatment strategies for PsA.

A study protocol for a double-blinded, randomised, placebo-controlled trial on the use of encapsulated FMT for reducing the side effects of HSCT: the HSCT-BIOME study

BACKGROUND

The composition of the gut microbiota both prior to and after haematopoietic stem cell transplantation (HSCT) is increasingly implicated in the outcomes of HSCT, including infections, poor immune reconstitution and disease relapse. Faecal microbiota transplantation (FMT) offers a potential strategy of supporting the gut microbiota and improve HSCT outcomes. Although FMT has been investigated in HSCT recipients, it has largely been evaluated therapeutically for indications such as infection, or once immunocompetency is regained.

METHODS

Peri-HSCT FMT (i.e. before and after HSCT) will be administered to eligible participants (adults undergoing autologous HSCT for a haematological malignancy) over two courses, with the first delivered immediately prior to conditioning and the second starting when ANC > 0.8. Following an open-label, safety run in (N = 5), peri-HSCT FMT will be evaluated for its efficacy in 51 participants, randomised 2:1 to FMT or placebo. The primary outcome is the proportion of participants who develop severe gastrointestinal toxicity defined by 3 consecutive days of severe diarrhoea (Bristol Stool Chart 6+), at a frequency of 4 + bowel movements/day within 3 weeks of HSCT. Safety is defined as the incidence of treatment-emergent adverse events (TE-AEs). Tolerability is defined as the incidence of TE-AEs and adherence to FMT.

DISCUSSION

The HSCT-BIOME study is a multi-centre, double-blind, randomised placebo-controlled trial designed to determine the tolerability, safety and efficacy of orally-administered encapsulated FMT to promote the stability of the gastrointestinal microenvironment for HSCT recipients. Peri-HSCT delivered FMT is hypothesised to promote microbial composition both before and following HSCT. Thus, the study will determine if administration of FMT post-HSCT during the neutropenic phase will enhance efficacy.

TRIAL REGISTRATION

ACTRN12624001104549. Date of registration: September 19, 2024 (prospectively registered).

Gut microbiota and gastrointestinal tumors: insights from a bibliometric analysis

Introduction

Despite the growing number of studies on the role of gut microbiota in treating gastrointestinal tumors, the overall research trends in this field remain inadequately characterized.

Methods

A bibliometric analysis was conducted using publications retrieved from the Web of Science Core Collection (up to September 30, 2024). Analytical tools including VOSviewer, CiteSpace, and an online bibliometric platform were employed to evaluate trends and hotspots.

Results

Analysis of 1,421 publications revealed significant geographical disparities in research output, with China and the United States leading contributions. Institutionally, the University of Adelaide, Zhejiang University, and Shanghai Jiao Tong University were prominent contributors. Authorship analysis identified Hannah R. Wardill as the most prolific author, while the International Journal of Molecular Sciences emerged as a leading journal. Rapidly growing frontiers include "proliferation," "inhibition," "immunotherapy," "drug delivery," and "tumorigenesis."

Discussion

This study provides a comprehensive overview of research trends and highlights emerging directions, aiming to advance scientific and clinical applications of gut microbiota in gastrointestinal tumor therapy.

Exploring the Role of Gut Microbiota and Probiotics in Acute Pancreatitis: A Comprehensive Review

Acute pancreatitis (AP) is a common and potentially severe gastrointestinal condition characterized by acute inflammation of the pancreas. The pathophysiology of AP is multifactorial and intricate, involving a cascade of events that lead to pancreatic injury and systemic inflammation. The progression of AP is influenced by many factors, including genetic predispositions, environmental triggers, and immune dysregulation. Recent studies showed a critical involvement of the gut microbiota in shaping the immune response and modulating inflammatory processes during AP. This review aims to provide a comprehensive overview of the emerging role of gut microbiota and probiotics in AP. We analyzed the implication of gut microbiota in pathogenesis of AP and the modification during an acute attack. The primary goals of microbiome-based therapies, which include probiotics, prebiotics, antibiotics, fecal microbiota transplantation, and enteral nutrition, are to alter the composition of the gut microbial community and the amount of metabolites derived from the microbiota. By resetting the entire flora or supplementing it with certain beneficial organisms and their byproducts, these therapeutic approaches aim to eradicate harmful microorganisms, reducing inflammation and avoiding bacterial translocation and the potential microbiota-based therapeutic target for AP from nutrition to pre- and probiotic supplementation to fecal transplantation.

Outcomes of Fecal Microbiota Transplantation for Clostridioides difficile Infection in South Australia

Background

Fecal microbiota transplantation (FMT) sourced from a bank of prescreened anaerobically processed frozen donor stool has been available in South Australia since 2013. This study aimed to evaluate the real-world clinical and safety outcomes of FMT for recurrent, refractory, and/or severe or fulminant Clostridioides difficile infection (CDI) facilitated via this centralized facility.

Methods

Donor screening test data were prospectively collected on all donors who passed prescreening evaluations between April 2013 and August 2023. The South Australian FMT for CDI database prospectively recorded outcomes for consecutive patients who underwent FMT for CDI from August 2013 to May 2023 in South Australia.

Results

An overall 98 potential donors passed prescreening assessments and underwent laboratory screening tests: 32 (33%) had tests that failed, 5 (5%) had incomplete screening, and 61 (62%) passed. Detection of an extended-spectrum β-lactamase-producing organism (9/65, 14%) was the common reason for ineligibility following completion of screening tests. In total 220 cases of CDI were recorded, and follow-up data were available in 216. Primary cure occurred in 84% of cases (182/216): 88% (132/150) for recurrent CDI, 76% (50/66) for refractory CDI, 85% (51/60) for severe disease, and 65% (17/26) for fulminant disease. Repeat FMT was delivered in 23 of 34 cases (68%), with secondary cure in 74% (17/23 cases). Serious adverse events were observed in 6 patients overall (3%). No deaths were directly attributable to FMT.

Conclusions

FMT was safe and efficacious for management of recurrent and refractory CDI over a 10-year period in a real-world prospective Australian cohort. Further studies to optimize the use of FMT for severe and fulminant CDI are warranted.

Management of severe and fulminant Clostridioides difficile infection in adults

Clostridioides difficile (formerly known as Clostridium difficile) is a significant cause of healthcare-associated infection with symptoms ranging from diarrhoea and abdominal pain to pseudomembranous colitis and toxic megacolon. Severe disease can pose a significant morbidity and mortality risk and is to be considered a medical emergency. The emergence of a new C. difficile ribotype with an estimated mortality rate of 20% (ribotype 995) has prompted a re-review of the evidence and guidelines around managing severe C. difficile infections (CDI). International guidance on the management of CDI varies regarding first-line antibiotic choice. Metronidazole is no longer favoured as first line due to concerns around resistance, and vancomycin and fidaxomicin are now recommended as first line options. Antibiotic therapy should be used in conjunction with good supportive measures and early consideration of surgical management. Faecal microbiota transplant can be utilized in recurrent CDI and may be useful in severe disease. Severe CDI is a significant ongoing threat to public health, and further research into effective management is essential to ensure the best possible outcomes for patients.

Advances in Fecal Microbiota Transplantation for Gut Dysbiosis-Related Diseases

This article provides an overview of the advancements in the application of fecal microbiota transplantation (FMT) in treating diseases related to intestinal dysbiosis. FMT involves the transfer of healthy donor fecal microbiota into the patient's body, aiming to restore the balance of intestinal microbiota and thereby treat a variety of intestinal diseases such as recurrent Clostridioides difficile infection (rCDI), inflammatory bowel disease (IBD), constipation, short bowel syndrome (SBS), and irritable bowel syndrome (IBS). While FMT has shown high efficacy in the treatment of rCDI, further research is needed for its application in other chronic conditions. This article elaborates on the application of FMT in intestinal diseases and the mechanisms of intestinal dysbiosis, as well as discusses key factors influencing the effectiveness of FMT, including donor selection, recipient characteristics, treatment protocols, and methods for assessing microbiota. Additionally, it emphasizes the key to successful FMT. Future research should focus on optimizing the FMT process to ensure long-term safety and explore the potential application of FMT in a broader range of medical conditions.

Fecal microbiota transplantation: transitioning from chaos and controversial realm to scientific precision era

With the popularization of modern lifestyles, the spectrum of intestinal diseases has become increasingly diverse, presenting significant challenges in its management. Traditional pharmaceutical interventions have struggled to keep pace with these changes, leaving many patients refractory to conventional pharmaceutical treatments. Fecal microbiota transplantation (FMT) has emerged as a promising therapeutic approach for enterogenic diseases. Still, controversies persist regarding its active constituents, mechanism of action, scheme of treatment evaluation, indications, and contraindications. In this review, we investigated the efficacy of FMT in addressing gastrointestinal and extraintestinal conditions, drawing from follow-up data on over 8000 patients. We systematically addressed the controversies surrounding FMT's clinical application. We delved into key issues such as its technical nature, evaluation methods, microbial restoration mechanisms, and impact on the host-microbiota interactions. Additionally, we explored the potential colonization patterns of FMT-engrafted new microbiota throughout the entire intestine and elucidated the specific pathways through which the new microbiota modulates host immunity, metabolism, and genome.

Fecal microbiota transplantation: application scenarios, efficacy prediction, and factors impacting donor-recipient interplay

Fecal microbiota transplantation (FMT) represents a therapeutic approach that directly regulates the gut microbiota of recipients, normalizes its composition and reaping therapeutic rewards. Currently, in addition to its general application in treating Clostridium difficile (C. difficile) infection (CDI), FMT treatment has also been extended to the fields of other gastrointestinal diseases, infections, gut-liver or gut-brain axis disorders, metabolic diseases and cancer, etc. Prior to FMT, rigorous donor screening is essential to reduce the occurrence of adverse events. In addition, it is imperative to evaluate whether the recipient can safely and effectively undergo FMT treatment. However, the efficacy of FMT is influenced by the complex interactions between the gut microbiota of donor and recipient, the degree of donor microbiota engraftment is not necessarily positively related with the success rate of FMT. Furthermore, an increasing number of novel factors affecting FMT outcomes are being identified in recent clinical trials and animal experiments, broadening our understanding of FMT treatment. This article provides a comprehensive review of the application scenarios of FMT, the factors influencing the safety and efficacy of FMT from the aspects of both the donors and the recipients, and summarizes how these emerging novel regulatory factors can be combined to predict the clinical outcomes of patients undergoing FMT.

Intestinal Microbiota Modulation by Fecal Microbiota Transplantation in Nonalcoholic Fatty Liver Disease

Numerous factors are involved in the pathogenesis of nonalcoholic fatty liver disease (NAFLD), which are responsible for its development and progression as an independent entity, but also thanks to their simultaneous action. This is explained by the hypothesis of multiple parallel hits. These factors are insulin resistance, lipid metabolism alteration, oxidative stress, endoplasmic reticulum stress, inflammatory cytokine liberation, gut microbiota dysbiosis or gut-liver axis activation. This is a systematic review which has an aim to show the connection between intestinal microbiota and the role of its disbalance in the development of NAFLD. The gut microbiota is made from a wide spectrum of microorganisms that has a systemic impact on human health, with a well-documented role in digestion, energy metabolism, the stimulation of the immune system, synthesis of essential nutrients, etc. It has been shown that dysbiosis is associated with all three stages of chronic liver disease. Thus, the modulation of the gut microbiota has attracted research interest as a novel therapeutic approach for the management of NAFLD patients. The modification of microbiota can be achieved by substantial diet modification and the application of probiotics or prebiotics, while the most radical effects are observed by fecal microbiota transplantation (FMT). Given the results of FMT in the context of metabolic syndrome (MetS) and NAFLD in animal models and scarce pilot studies on humans, FMT seems to be a promising treatment option that could reverse intestinal dysbiosis and thereby influence the course of NAFLD.

Impact of Fecal Microbiota Transplant Formulations, Storage Conditions, and Duration on Bacterial Viability, Functionality, and Clinical Outcomes in Patients with Recurrent Clostridioides difficile Infection

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.

Rigorous Donor Selection for Fecal Microbiota Transplantation in Active Ulcerative Colitis: Key Lessons From a Randomized Controlled Trial Halted for Futility

BACKGROUND & AIMS

Rigorous donor preselection on microbiota level, strict anaerobic processing, and repeated fecal microbiota transplantation (FMT) administration were hypothesized to improve FMT induction of remission in ulcerative colitis (UC).

METHODS

The RESTORE-UC trial was a multi-centric, double-blind, sham-controlled, randomized trial. Patients with moderate to severe UC (defined by total Mayo 4-10) were randomly allocated to receive 4 anaerobic-prepared allogenic or autologous donor FMTs. Allogenic donor material was selected after a rigorous screening based on microbial cell count, enterotype, and the abundance of specific genera. The primary endpoint was steroid-free clinical remission (total Mayo ≤2, no sub-score >1) at week 8. A pre-planned futility analysis was performed after 66% (n = 72) of intended inclusions (n = 108). Quantitative microbiome profiling (n = 44) was performed at weeks 0 and 8.

RESULTS

In total, 72 patients were included, of which 66 received at least 1 FMT (allogenic FMT, n = 30 and autologous FMT, n = 36). At week 8, respectively, 3 and 5 patients reached the primary endpoint of steroid-free clinical remission (P = .72), indicating no treatment difference of at least 5% in favor of allogenic FMT. Hence, the study was stopped due to futility. Microbiome analysis showed numerically more enterotype transitions upon allogenic FMT compared with autologous FMT, and more transitions were observed when patients were treated with a different enterotype than their own at baseline (P = .01). Primary response was associated with lower total Mayo scores, lower bacterial cell counts, and higher Bacteroides 2 prevalence at baseline.

CONCLUSION

The RESTORE-UC trial did not meet its primary endpoint of increased steroid-free clinical remission at week 8. Further research should additionally consider patient selection, sterilized sham-control, increased frequency, density, and viability of FMT prior to administration.

CLINICALTRIALS

gov, Number: NCT03110289.

Bridging gap in the treatment of Alzheimer's disease via postbiotics: Current practices and future prospects

Aging is an extremely significant risk associated with neurodegeneration. The most prevalent neurodegenerative disorders (NDs), such as Alzheimer's disease (AD) are distinguished by the prevalence of proteinopathy, aberrant glial cell activation, oxidative stress, neuroinflammation, defective autophagy, cellular senescence, mitochondrial dysfunction, epigenetic changes, neurogenesis suppression, increased blood-brain barrier permeability, and intestinal dysbiosis that is excessive for the patient's age. Substantial body studies have documented a close relationship between gut microbiota and AD, and restoring a healthy gut microbiota may reduce or even ameliorate AD symptoms and progression. Thus, control of the microbiota in the gut has become an innovative model for clinical management of AD, and rising emphasis is focused on finding new techniques for preventing and/or managing the disease. The etiopathogenesis of gut microbiota in driving AD progression and supplementing postbiotics as a preventive and therapeutic treatment for AD is discussed. The review additionally discusses the use of postbiotics in AD prophylaxis and therapy, portraying them as substances that address senescence-triggered dysfunctions and are worthy of translating from bench to biopharmaceutical market in response to "silver consumers" needs. The current review examines and evaluates the impact of postbiotics as whole and specific metabolites, such as short-chain fatty acids (SCFAs), lactate, polyamines, polyphenols, tryptophan metabolites, exopolysaccharides, and bacterial extracellular vesicles, on the aging-associated processes that reinforce AD. Moreover, it provides an overview of the most recent data from both clinical and preclinical research involving the use of postbiotics in AD.

Longitudinal Changes in Fecal Microbiota During Hospitalization in Horses With Different Types of Colic

BACKGROUND

Research on fecal microbiota changes during hospitalization of horses with colic is emerging.

OBJECTIVES

Describe changes of the fecal microbiota during hospitalization of horses with colic caused by inflammatory (INFL), simple (SIMPLE), and strangulated (STR) obstructions, and investigate associations with survival.

ANIMALS

Twenty-three horses with colic: 9 in INFL, 5 in STR, and 9 in SIMPLE groups. Seventeen horses survived, and 6 were euthanized.

METHODS

Prospective observational study. Fecal samples were collected on admission (D1), on days 3 (D3) and 5 (D5). Bacterial taxonomy profiling was obtained by V1V3 16S amplicon sequencing. Data were compared using a 2-way permutational analysis of variance (PERMANOVA). Linear discriminant analysis Effect Size (LEfSE) analysis identified significant bacterial population differences, with significance set at p < 0.05 and a linear discriminant analysis (LDA) cut-off > 3.0.

RESULTS

Alpha diversity indices remained stable during hospitalization within each colic group. However, at D5, the INFL group had significantly higher richness (p < 0.01) and diversity (Shannon, p < 0.001 and Simpson, p < 0.05) than other colic types. Beta diversity (Jaccard membership and Bray-Curtis indices) was significantly different in the INFL compared to SIMPLE and STR groups (both p < 0.001) but not between SIMPLE and STR. Beta diversity membership analysis by analysis of molecular variance (AMOVA) indicated a significant difference between survivors and non-survivors within the INFL group (p < 0.01). Increased relative abundances of Bacilliculturomica and Saccharofermentans were associated with survival.

CONCLUSIONS

Microbiota showed no significant variation over 5 days of hospitalization. Colic type influenced fecal microbiota more than hospitalization duration. Specific bacterial populations may differ between survival and non-survival groups.

Case report of clostridium difficile infection after rectal resection with ileostomy

Colorectal cancer is the third most common cancer worldwide, with high incidence and mortality rates. Surgical resection is the primary treatment for rectal cancer. To reduce the occurrence and severity of postoperative complications such as anastomotic leakage, prophylactic ileostomy is often performed concurrently. However, following ileostomy creation, there is a disruption in intestinal ecology, making patients susceptible to clostridium difficile infection. clostridium difficile is a Gram-positive anaerobic spore-forming bacterium that is resistant to most antibiotics due to spore formation, leading to high recurrence rates and treatment failure. Additionally, in the early stages of clostridium difficile infection, increased ileostomy output can be challenging to differentiate from normal postoperative conditions, potentially resulting in missed diagnosis, delayed treatment, and increased healthcare burden.This case report describes a case of high out-put ileostomy caused by clostridium difficile infection following rectal resection with ileostomy, which was successfully treated by fecal microbiota transplantation, providing evidence-based medicine for clinical practice.

In vitro validation concept for lyophilized fecal microbiota products with a focus on bacterial viability

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.

Exploring Gut Microbiota-Targeted Therapies for Canine Idiopathic Epilepsy

Epilepsy stands out as one of the most prevalent chronic neurological conditions affecting companion animals. Recent research has increasingly focused on exploring the role of gut microbiota in influencing neurological conditions, like epilepsy. This influence stems from the bidirectional communication pathways between gut bacteria and the brain, which involve metabolic, neural, immunological, and endocrine mechanisms. In fact, a balanced and stable gut microbiota is essential to maintaining normal gut physiology and ensuring appropriate signaling along the gut-brain axis. Conversely, dysbiosis can have detrimental effects on gut physiology and may contribute to the development or exacerbation of neurological conditions, including epilepsy. Considering these findings, this review article aims to deepen the understanding of the mechanisms underlying the microbiota-gut-brain connection in the context of canine idiopathic epilepsy. Moreover, this review presents recent data on innovative gut-related therapeutic strategies for canine idiopathic epilepsy treatment.

Exercise, the Gut Microbiome and Gastrointestinal Diseases: Therapeutic Impact and Molecular Mechanisms

The benefits of regular physical activity (PA) on disease prevention and treatment outcomes have been recognized for centuries. However, only recently has interorgan communication triggered by the release of "myokines" from contracting skeletal muscles emerged as a putative mechanism by which exercise confers protection against numerous disease states. Cross-talk between active skeletal muscles and the gut microbiota reveal how regular PA boosts host immunity, facilitates a more diverse gut microbiome and functional metabolome, and plays a positive role in energy homeostasis and metabolic regulation. In contrast, and despite the large interindividual variation in the human gut microbiome, reduced microbial diversity has been implicated in several diseases of the gastrointestinal (GI) tract, systemic immune diseases, and cancers. Although prolonged, intense, weight-bearing exercise conducted in extreme conditions can increase intestinal permeability, compromising gut-barrier function and resulting in both upper and lower GI symptoms, these are transient and benign. Accordingly, the gut microbiome has become an attractive target for modulating many of the positive effects of regular PA on GI health and disease, although the precise dose of exercise required to induce favourable changes in the microbiome and enhance host immunity is currently unknown. Future efforts should concentrate on gaining a deeper understanding of the factors involved in exercise-gut interactions through the generation of functional 'omics readouts (ie, metatranscriptomics, metaproteomics, and metabolomics) that have the potential to identify functional traits of the microbiome that are linked to host health and disease states, and validating these interactions in experimental and preclinical systems. A greater understanding of how PA interacts with the GI tract and the microbiome may enable targeted therapeutic strategies to be developed for individuals and populations at risk for a variety of GI diseases.

Therapeutic role of gut microbiota in lung injury-related cognitive impairment

Lung injury can lead to specific neurocognitive dysfunction, and the "triple-hit" phenomenon may be the key theoretical mechanism for the progressive impairment of lung injury-related cognitive impairment. The lung and brain can communicate biologically through immune regulation pathway, hypoxic pathway, neural circuit, mitochondrial dysfunction, and microbial influence, which is called the "lung-brain axis." The gut microbiota is a highly complex community of microorganisms that reside in the gut and communicate with the lung via the "gut-lung axis." The dysregulation of gut microbiota may lead to the migration of pathogenic bacteria to the lung, and directly or indirectly regulate the lung immune response through their metabolites, which may cause or aggravate lung injury. The gut microbiota and the brain interact through the "gut-brain axis." The gut microbiota can influence and regulate cognitive function and behavior of the brain through neural pathway mechanisms, immune regulation pathway and hypothalamic-pituitary-adrenal (HPA) axis regulation. Based on the gut microbiota regulation mechanism of the "gut-lung axis" and "gut-brain axis," combined with the mechanisms of cognitive impairment caused by lung injury, we proposed the "triple-hit" hypothesis. It states that the pathophysiological changes of lung injury trigger a series of events such as immune disorder, inflammatory responses, and microbiota changes, which activate the "lung-gut axis," thus forming a "triple-hit" that leads to the development or deterioration of cognitive impairment. This hypothesis provides a more comprehensive framework for studying and understanding brain dysfunction in the context of lung injury. This review proposes the existence of an interactive tandem network for information exchange among the gut, lung, and brain, referred to as the "gut-lung-brain axis." It further explores the potential mechanism of lung injury-related cognitive impairment caused by multiple interactions of gut microbiota in the "gut-lung-brain axis." We found that there are many numerous pathophysiological factors that influence the interaction within the "gut-lung-brain axis." The impact of gut microbiota on cognitive functions related to lung injury may be mediated through mechanisms such as the "triple-hit" hypothesis, direct translocation of microbes and their metabolites, hypoxic pathway, immune modulation, vagal nerve activity, and the HPA axis regulation, among others. As the research deepens, based on the "triple-hit" hypothesis of lung injury, it is further discovered that gut microbial therapy can significantly change the pathogenesis of the inflammatory process on the "gut-lung-brain axis." It can also relieve lung injury and therapeutically modulate brain function and behavior. This perspective provides a new idea for the follow-up treatment of lung injury-related cognitive impairment caused by dysregulation of gut microbiota.

Guidance for Fecal Microbiota Transplantation Trials in Ulcerative Colitis: The Second ROME Consensus Conference

BACKGROUND

Fecal microbiota transplantation (FMT) is emerging as a potential treatment modality for individuals living with inflammatory bowel disease (IBD). Despite its promise, the effectiveness of FMT for treating IBD, particularly for ulcerative colitis (UC), still requires thorough clinical investigation. Notwithstanding differences in methodologies, current studies demonstrate its potential for inducing remission in UC patients. Therefore, standardized and robust randomized clinical trials (RCTs) are needed to further support its efficacy for managing UC. The aim of the second Rome Consensus Conference was to address gaps and uncertainties identified in previous research regarding FMT and to offer a robust framework for future studies applied to the treatment of UC.

METHODS

Global experts in the field of clinical IBD, mucosal immunology, and microbiology (N = 48) gathered to address the need for standardized clinical trials in FMT investigation. The group focused on key issues, such as stool donation, donor selection, characterization of fecal biomass, potential administration routes, as well as the process of induction, maintenance, and endpoint readouts.

RESULTS AND CONCLUSIONS

The consensus achieved during this conference established standardization of methods and protocols to enhance the current quality of research, with the aim of eventual implementation of FMT in managing UC and the ultimate goal of improving patient outcomes.

Akkermansia muciniphila identified as key strain to alleviate gut barrier injury through Wnt signaling pathway

As the largest mucosal surface, the gut has built a physical, chemical, microbial, and immune barrier to protect the body against pathogen invasion. The disturbance of gut microbiota aggravates pathogenic bacteria invasion and gut barrier injury. Fecal microbiota transplantation (FMT) is a promising treatment for microbiome-related disorders, where beneficial strain engraftment is a significant factor influencing FMT outcomes. The aim of this research was to explore the effect of FMT on antibiotic-induced microbiome-disordered (AIMD) models infected with enterotoxigenic Escherichia coli (ETEC). We used piglet, mouse, and intestinal organoid models to explore the protective effects and mechanisms of FMT on ETEC infection. The results showed that FMT regulated gut microbiota and enhanced the protection of AIMD piglets against ETEC K88 challenge, as demonstrated by reduced intestinal pathogen colonization and alleviated gut barrier injury. Akkermansia muciniphila (A. muciniphila) and Bacteroides fragilis (B. fragilis) were identified as two strains that may play key roles in FMT. We further investigated the alleviatory effects of these two strains on ETEC infection in the AIMD mice model, which revealed that A. muciniphila and B. fragilis relieved ETEC-induced intestinal inflammation by maintaining the proportion of Treg/Th17 cells and epithelial damage by moderately activating the Wnt/β-catenin signaling pathway, while the effect of A. muciniphila was better than B. fragilis. We, therefore, identified whether A. muciniphila protected against ETEC infection using basal-out and apical-out intestinal organoid models. A. muciniphila did protect the intestinal stem cells and stimulate the proliferation and differentiation of intestinal epithelium, and the protective effects of A. muciniphila were reversed by Wnt inhibitor. FMT alleviated ETEC-induced gut barrier injury and intestinal inflammation in the AIMD model. A. muciniphila was identified as a key strain in FMT to promote the proliferation and differentiation of intestinal stem cells by mediating the Wnt/β-catenin signaling pathway.

Therapeutic Targets and Approaches to Manage Inflammation of NAFLD

Non-alcoholic fatty liver disease (NAFLD) and its advanced form, non-alcoholic steatohepatitis (NASH), are the leading causes of chronic liver disease globally. They are driven by complex mechanisms where inflammation plays a pivotal role in disease progression. Current therapies, including lifestyle changes and pharmacological agents, are limited in efficacy, particularly in addressing the advanced stages of the disease. Emerging approaches targeting inflammation, metabolic dysfunction, and fibrosis offer promising new directions, though challenges such as treatment complexity and heterogeneity persist. This review concludes the main therapeutic targets and approaches to manage inflammation currently and emphasizes the critical need for future drug development and combination therapy for NAFLD/NASH management.

International consensus statement on microbiome testing in clinical practice

There is growing interest in the potential exploitation of the gut microbiome as a diagnostic tool in medicine, but evidence supporting its clinical usefulness is scarce. An increasing number of commercial providers offer direct-to-consumer microbiome diagnostic tests without any consensus on their regulation or any proven value in clinical practice, which could result in considerable waste of individual and health-care resources and potential drawbacks in the clinical management of patients. We convened an international multidisciplinary expert panel to standardise best practices of microbiome testing for clinical implementation, including recommendations on general principles and minimum requirements for their provision, indications, pre-testing protocols, method of analyses, reporting of results, and potential clinical value. We also evaluated current knowledge gaps and future directions in this field. We aimed to establish a framework to regulate the provision of microbiome testing and minimise the use of inappropriate tests and pave the way for the evidence-based development and use of human microbiome diagnostics in clinical medicine.

Recent advances in acute gastrointestinal graft versus host disease (aGvHD): aspects of steroid-resistant disease

Acute Graft versus Host Disease (aGvHD) is a common immunological complication occurring in patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). Moreover, aGvHD is associated with a higher risk of infections and metabolic complications, affecting non-relapse mortality. Progress in transplantation has changed the prophylactic and therapeutic strategies of aGvHD and improved patient outcomes. The standard first-line therapy remains steroids, with a response rate of about 50%. The Janus Kinase 2 (JAK2) inhibitor, ruxolitinib, is an effective second-line therapy. The management of patients who developed a disease that is refractory to steroids and ruxolitinib, especially in the severe gastrointestinal forms of aGvHD, is not validated and remains an unmet medical need. In the article, we present the current clinical practice, as well as the latest advances targeting pathophysiological pathways of GvHD and gut microbiota, which may be a potential future of aGvHD therapy.

The oral-gut microbiota axis: a link in cardiometabolic diseases

The oral-gut microbiota axis plays a crucial role in cardiometabolic health. This review explores the interactions between these microbiomes through enteric, hematogenous, and immune pathways, resulting in disruptions in microbial balance and metabolic processes. These disruptions contribute to systemic inflammation, metabolic disorders, and endothelial dysfunction, which are closely associated with cardiometabolic diseases. Understanding these interactions provides insights for innovative therapeutic strategies to prevent and manage cardiometabolic diseases.

Randomised double-blind placebo-controlled trial protocol to evaluate the therapeutic efficacy of lyophilised faecal microbiota capsules amended with next-generation beneficial bacteria in individuals with metabolic dysfunction-associated steatohepatitis

BACKGROUND

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.

METHODS AND ANALYSIS

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.

ETHICS AND DISSEMINATION

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.

TRIAL REGISTRATION NUMBER

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

Prolonged storage reduces viability of Peptacetobacter (Clostridium) hiranonis and core intestinal bacteria in fecal microbiota transplantation preparations for dogs

Introduction

Fecal microbiota transplantation (FMT) has been described useful as an adjunct treatment for chronic enteropathy in dogs. Different protocols can be used to prepare and store FMT preparations, however, the effect of these methods on microbial viability is unknown. We aimed (1) to assess the viability of several core intestinal bacterial species by qPCR and (2) to assess Peptacetobacter (Clostridium) hiranonis viability through culture to further characterize bacterial viability in different protocols for FMT preparations.

Methods

Bacterial abundances were assessed in feces from six healthy dogs by qPCR after propidium monoazide (PMA-qPCR) treatment for selective quantitation of viable bacteria. Conservation methods tested included lyophilization (stored at 4°C and at -20°C) and freezing with glycerol-saline solution (12.5%) and without any cryoprotectant (stored at -20°C). Additionally, the abundance of P. hiranonis was quantified using bacterial culture.

Results

Using PMA-qPCR, the viability of Faecalibacterium, Escherichia coli, Streptococcus, Blautia, Fusobacterium, and P. hiranonis was reduced in lyophilized fecal samples kept at 4°C and -20°C up to 6 months (p < 0.05). In frozen feces without cryoprotectant, only Streptococcus and E. coli were not significantly reduced for up to 3 months (p > 0.05). Lastly, no differences were observed in the viability of those species in glycerol-preserved samples up to 6 months (p > 0.05). When using culture to evaluate the viability of P. hiranonis, we observed that P. hiranonis abundance was lower in lyophilized samples kept at 4°C than -20°C; and P. hiranonis abundance was higher in glycerol-preserved samples for up to 6 months than in samples preserved without glycerol for up to 3 months. Moreover, the highest abundance of P. hiranonis was observed in glycerol-preserved feces. After 3 months, P. hiranonis was undetectable by culture in 83% (5/6) of the frozen samples without glycerol.

Discussion

While the lyophilization procedure initially reduced P. hiranonis abundance, P. hiranonis viability was stable thereafter for up to 6 months at -20°C. The higher bacterial viability detected in fecal samples preserved with glycerol confirms the use of this cryoprotectant as a reliable method to keep bacteria alive in the presence of fecal matrix for FMT purposes.

FAecal micRobiota transplantation in primary sclerosinG chOlangitis (FARGO): study protocol for a randomised, multicentre, phase IIa, placebo-controlled trial

INTRODUCTION

Primary sclerosing cholangitis (PSC) is the classical hepatobiliary manifestation of inflammatory bowel disease (IBD). The strong association between gut and liver inflammation has driven several pathogenic hypotheses to which the intestinal microbiome is proposed to contribute. Pilot studies of faecal microbiota transplantation (FMT) in PSC and IBD are demonstrated to be safe and associated with increased gut bacterial diversity. However, the longevity of such changes and the impact on markers of disease activity and disease progression have not been studied. The aim of this clinical trial is to determine the effects of repeated FMT as a treatment for PSC-IBD.

METHODS AND ANALYSIS

FAecal micRobiota transplantation in primary sclerosinG chOlangitis (FARGO) is a phase IIa randomised placebo-controlled trial to assess the efficacy and safety of repeated colonic administration of FMT in patients with non-cirrhotic PSC-IBD. Fifty-eight patients will be recruited from six sites across England and randomised in a 1:1 ratio between active FMT or FMT placebo arms. FMT will be manufactured by the University of Birmingham Microbiome Treatment Centre, using stool collected from rigorously screened healthy donors. A total of 8 weekly treatments will be delivered; the first through colonoscopic administration (week 1) and the remaining seven via once-weekly enema (up to week 8). Participants will then be followed on a 12-weekly basis until week 48 from the first treatment visit. The primary efficacy outcome will be to determine the effect of FMT on serum alkaline phosphatase values over time (end of study at 48 weeks). Key secondary outcomes will be to evaluate the impact of FMT on other liver biochemical parameters, PSC risk scores, circulating and imaging markers of liver fibrosis, health-related quality of life measures, IBD activity and the incidence of PSC-related clinical events. Key translational objectives will be to identify mucosal metagenomic, metatranscriptomic, metabolomic and immunological pathways associated with the administration of FMT.

ETHICS AND DISSEMINATION

The protocol was approved by the South Central-Hampshire B Research Ethics Committee (REC 23/SC/0147). Participants will be required to provide written informed consent. The results of this trial will be disseminated through national and international presentations and peer-reviewed publications.

TRIAL REGISTRATION NUMBER

The trial was registered at ClinicalTrials.gov on 23 February 2024 (NCT06286709). Weblink: Study Details | FAecal Microbiota Transplantation in primaRy sclerosinG chOlangitis | ClinicalTrials.gov.

In vitro fermentation characteristics of dietary fibers using fecal inoculum from dogs consuming commercial or grain kefir

Traditional grain kefir is produced from the fermentation of milk with yeast- and bacteria-containing cultures. To maintain consistency and adhere to food safety guidelines, commercial kefir products are based on starter bacterial cultures. Bacterial profiles of starter vs. grain kefirs differ, and their influence on health effects is unknown. Our objectives were to determine the in vitro fermentation characteristics of common dietary fibers using fecal inoculum from dogs supplemented with kefir or kefir bacterial culture as inoculum. Healthy adult dogs were allotted to one of 3 treatments and supplemented for 14 d (n = 4/treatment): 1) 2% reduced-fat milk treated with lactase (CNTL), 2) starter kefir (S-Kefir), or 3) grain kefir (G-Kefir). After 14 d, fresh fecal samples were collected and frozen in a 20% glycerol solution. For the in vitro experiment, fecal samples were thawed, diluted in an anaerobic diluting solution, and used to inoculate tubes containing semi-defined medium and either cellulose (CEL), pectin (PC), beet pulp (BP), or chicory pulp (CP). Tubes were incubated for 0, 6, 12, or 18 h, with short-chain fatty acids (SCFA), pH, and microbiota measured at each time point. A second in vitro experiment was conducted using similar methods and measurements but with S-Kefir and G-Kefir as inoculum sources. Effects of treatment (inoculum), time, and treatment*time interactions within the fiber source were analyzed statistically using Mixed Models and repeated measures, with P < 0.05 being significant. Using fecal inoculum, BP and PC were rapidly fermented, leading to large pH reductions, SCFA increases, and microbiota shifts. pH change was of greater (P < 0.05) magnitude (PC) and higher (P < 0.05) kinetic rate (CP) when using feces from dogs fed S-Kefir or G-Kefir than controls. Butyrate increases were greater (P < 0.05) in tubes inoculated with G-Kefir feces than in S-Kefir or control feces. When PC and BP were fermented, tubes with S-Kefir feces had greater (P < 0.05) acetate, propionate, and total SCFA increases than G-Kefir or control feces. Fermentations were slower when using kefir cultures as inoculum, but some differences were noted. Bacterial beta diversity and relative abundances shifted over time within each substrate and were unique to the inoculum source. Our data suggest that the activity of kefir bacterial populations differs and that kefir consumption changes the abundance and activity of the fecal microbiota of dogs, justifying in vivo investigation.