Ulcerative Colitis in Response to Fecal Microbiota Transplantation via Modulation of Gut Microbiota and Th17/Treg Cell Balance

Gut Microbiome Modulation in Allergy Treatment: The Role of Fecal Microbiota Transplantation

The prevalence of allergic diseases has been rising, paralleling lifestyle changes and environmental exposures that have altered human microbiome composition. This review article examines the intricate relationship between the gut microbiome and allergic diseases, emphasizing the potential of fecal microbiota transplantation as a promising novel treatment approach. It explains how reduced microbial exposure in modern societies contributes to immune dysregulation and the increasing incidence of allergies. The discussion also addresses immune homeostasis and its modulation by the gut microbiome, highlighting the shift from eubiosis to dysbiosis in allergic conditions. Furthermore, this article reviews existing studies and emerging research on the role of fecal microbiota transplantation in restoring microbial balance, providing insights into its mechanisms, efficacy, and safety.

Improvement of the inflammation-damaged intestinal barrier and modulation of the gut microbiota in ulcerative colitis after FMT in the SHIME® model

BACKGROUND

Fecal microbiota transplantation (FMT) seems to be a promising approach in ulcerative colitis (UC) management with the aim of repopulating a patient's dysbiotic microbiota with beneficial bacteria and restore its metabolic activity to its healthy characteristics. Metabolites present after FMT may improve the function and integrity of the intestinal barrier, reduce inflammation, and thus induce remission in an UC patient. In this study we evaluated whether the Simulator of the Human Intestinal Microbial Ecosystem (SHIME®) model may be a suitable non-invasive alternative for studying and modifying the dysbiotic microbiota in UC by FMT application.

METHODS

SHIME® model was used to investigate microbial and metabolic changes in the gut microbiota of UC patient induced by FMT application. FMT-modified metabolites from SHIME® were applied to an in vitro model of the intestinal barrier (differentiated Caco-2 and HT-29-MTX-E12 cell lines) compromised by pro-inflammatory cytokines to study the effect of FMT on the intestinal barrier.

RESULTS

Qualitative and quantitative microbial analyses showed that FMT increased the diversity and variability of the microbiota in UC patient associated with a significant increase in total bacteria, Bacteroidota and Lactobacillus, as well as an increase in butyrate levels. In addition, an increase in the relative abundance of some important species such as Faecalibacterium prausnitzii and Bifidobacterium longum was observed, and there was also an enrichment of the microbiota with new species such as Blautia obeum, Roseburia faecis, Bifidobacterium adolescentis, Fusicatenibacter saccharivorans and Eubacterium rectale. Furthermore, microbial metabolites modulated by FMT from the SHIME® model prevented intestinal barrier damage and inhibited interleukin 8 (IL-8) and monocyte chemoattractant protein 1 (MCP-1) secretion when cell barriers were pretreated with FMT medium for 24 h. In summary, this study confirmed that a single dose of FMT beneficially modulated the composition and metabolic activity of the UC microbiota in the SHIME® model.

CONCLUSIONS

FMT favorably modulates the gut microbiota of UC patient cultured in the SHIME® model. FMT-modulated SHIME-derived microbial metabolites improve intact and inflamed intestinal barrier properties in vitro. Repeated applications are necessary to maintain the beneficial effect of FMT in SHIME® model.

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.

Mechanistic investigation and the optimal dose based on baicalin in the treatment of ulcerative colitis-A preclinical systematic review and meta-analysis

BACKGROUND

Ulcerative colitis (UC) is a type of inflammatory bowel disease, and current treatments often fall short, necessitating new therapeutic options. Baicalin shows therapeutic promise in UC animal models, but a systematic review is needed.

METHODS

A systematic search was conducted across databases including PubMed, EBSCO, Web of Science, and Science Direct, up to March 2024, identifying randomized controlled trials (RCTs) examining baicalin's impact on UC in animal models. Seventeen studies were selected through manual screening. Meta-analyses and subgroup analyses utilized Rev Man 5.3 and Stata 15.0 software to assess symptom improvement.

RESULTS

From 1304 citations, 17 were analyzed. Baicalin significantly modulated various biomarkers: HCS (SMD = -3.91), DAI (MD = -2.75), spleen index (MD = -12.76), MDA (SMD = -3.88), IL-6 (SMD = -10.59), IL-1β (SMD = -3.98), TNF-α (SMD = -8.05), NF-κB (SMD = -5.46), TLR4 (MD = -0.38), RORγ (MD = -0.89), MCP-1 (MD = -153.25), MPO (SMD = -7.34), Caspase-9 (MD = -0.93), Caspase-3 (MD = -0.45), FasL (MD = -1.20)) and enhanced BWC (MD = 0.06), CL (MD = 1.39), ZO-1 (MD = 0.44), SOD (SMD = 3.04), IL-10 mRNA (MD = 3.14), and FOXP3 (MD = 0.45) levels. Baicalin's actions may involve the PI3K/AKT, TLR4/NF-κB, IKK/IKB, Bcl-2/Bax, Th17/Treg, and TLRs/MyD88 pathways. Optimal therapeutic outcomes were predicted at dosages of 60-150 mg/kg over 10-14 weeks.

CONCLUSION

Baicalin demonstrates a multifaceted therapeutic potential in UC, attributed to its anti-inflammatory, antioxidant, anti-apoptotic, and intestinal barrier repair properties. While higher doses and longer treatments appear beneficial, further research, particularly human clinical trials, is necessary to verify its effectiveness and safety in people.

Gut-X axis

Recent advances in understanding the modulatory functions of gut and gut microbiota on human diseases facilitated our focused attention on the contribution of the gut to the pathophysiological alterations of many extraintestinal organs, including the liver, heart, brain, lungs, kidneys, bone, skin, reproductive, and endocrine systems. In this review, we applied the "gut-X axis" concept to describe the linkages between the gut and other organs and discussed the latest findings related to the "gut-X axis," including the underlying modulatory mechanisms and potential clinical intervention strategies.

Periplanta americana extract regulates the Th17/Treg cell balance via Notch1 in ulcerative colitis

Background

Periplanta americana extract (PAE), a traditional Chinese medicine (TCM) from Shen Nong Ben Cao Jing, has been used to treat ulcerative colitis (UC), various types of wounds and ulcers, infantile malnutrition, palpitation, asthma, and so on. However, the exact mechanisms of PAE in UC have still not been fully revealed. The study aims to explore the therapeutic effects and mechanisms of PAE in UC.

Methods

The efficacy of PAE was evaluated using a DSS-induced UC mice model and the colon inflammation and mucosal barrier were comprehensively assessed. Furthermore, Network pharmacological analysis was utilized to identify potential targets and signaling pathways of PAE in the UC treatment. The proportion and the markers of Th17 and Treg cells in the spleen and colon were examined. The signal transduction was detected in vivo. In vitro, an activated Notch1-mediated Th17/Treg was modeled, and the effect of PAE on the epithelial cell barrier was examined.

Results

PAE mitigated colon inflammation and intestinal barrier damage in UC mice. Network pharmacological analysis showed that the targets of UC intervention by PAE may be closely related to Th17 cell differentiation, the IL-17 signaling pathway, and cytokine-cytokine receptor interaction. Mechanistically, PAE regulated the balance of Th17/Treg and inhibited the Notch1/Math1 pathway in the colon of UC mice. In vitro, PAE intervention alleviated the activated Notch1-mediated Th17/Treg imbalance in Jurkat T cells. After notch1-activated Jurkat T cells were co-cultured with HCoEpic cells, the expressions of Occludin, ZO1 were higher in the HCoEpic cells.

Conclusion

PAE could alleviate colon inflammation and mucosal barrier damage in UC, which are related to the inhibition of Notch1 and the regulation of the Th17/Treg balance. PAE might be a potential candidate agent for UC treatment.

Gut microbiota contributes to the intestinal and extraintestinal immune homeostasis by balancing Th17/Treg cells

Gut microbiota is generally considered to play an important role in host health due to its extensive immunomodulatory activities. Th17 and Treg cells are two important CD4+ T cell subsets involved in immune regulation, and their imbalance is closely tied to many immune diseases. Recently, abundant researches have highlighted the importance of gut microbiota in supporting intestinal and extraintestinal immunity through the balance of Th17 and Treg cells. Here, we presented a comprehensive review of these findings. This review first provided an overview of gut microbiota, along with Th17/Treg cell differentiation and cytokine production. Subsequently, the review summarized the regulatory effects of gut microbiota (in terms of species, components, and metabolites) on the Th17/Treg cell balance in the local intestines and extraintestinal organs, such as lung, liver, brain, kidney, and bone. Specifically, the Th17 and Treg cells that can be modulated by gut microbiota originate not only from the gut and extraintestinal organs, but also from peripheral blood and spleen. Then, the microbial therapeutics, including probiotics, prebiotics, postbiotics, and fecal microbiota transplantation (FMT), were also reviewed because of their therapeutic potentials in addressing intestinal and extraintestinal diseases via the Th17/Treg axis. Finally, the review discussed the clinical applications and future study prospects of microbial therapeutics by targeting the Th17/Treg cell balance. In conclusion, this review focused on elucidating the regulatory effects of gut microbiota in balancing Th17/Treg cells to maintain intestinal and extraintestinal immune homeostasis, contributing to the further development and promotion of microbial therapeutics.

Lactobacillus paracasei JY062 and its exopolysaccharide enhance the intestinal barrier through macrophage polarization and Th17/Treg cell balance

Ulcerative colitis (UC) is an immune-mediated intestinal disease without a comprehensive cure, and the alleviation of UC has become an urgent problem. The results showed that JY062 with its EPS group (JEC) alleviated the intestinal barrier damage caused by LPS. After JEC intervention on Caco-2 cells, resulted in upregulation of ZO-1, Claudin-1, Occludin and MUC2 transcript levels and decreased mRNA expression of Claudin-2 (p < 0.05). JEC effectively attenuated the inflammatory response in UC mice and restoration of immunoglobulin levels (IgG, IgM and IgA), which resulted in shortening and swelling of the colon, disappearance of goblet cells, infiltration of inflammatory cells and mucosal damage were alleviated in mice. Similarly, changes in the expression of MUC2 and tight junction proteins after JEC intervention also occurred in UC mice. Administration of JEC significantly inhibited the differentiation of pro-inflammatory Th17 cells in the thymus and peripheral blood, promoted the differentiation of CD4+ T cells to Treg cells, and effectively regulated DSS-induced macrophage imbalance, which was manifested by the polarization of pro-inflammatory M1 macrophages to anti-inflammatory M2 macrophages. This study clearly demonstrates that JEC could significantly prevent intestinal barrier on DSS-induced experimental colitis and could be applied as a potential symbiotic strategy to assist in the alleviation of UC.

Gut Microbiota Features in Relation to Fecal Microbiota Transplantation Outcome in Ulcerative Colitis: A Systematic Review and Meta-Analysis

BACKGROUND & AIMS

Fecal microbiota transplantation (FMT) can induce remission in patients with ulcerative colitis, yet its efficacy needs improvement. We conducted a comprehensive evaluation of the current literature on microbial factors affecting outcome, as well as a meta-analysis on some of the largest datasets regarding composition.

METHODS

MEDLINE, Embase, and Cochrane were systematically searched through August 2024 for relevant studies. The quality of studies was analyzed with JBI tools and a composite critical appraisal score. Additionally, species-level data from 2 landmark FMT trials (the Transplantation of Feces in Ulcerative Colitis; Returning Nature's Homeostasis [TURN] and Fecal Microbiota Transplantation for Chronic Active Ulcerative Colitis [FOCUS] trials) were reanalyzed from a compositional perspective.

RESULTS

Out of 3755 citations identified, 56 met the inclusion criteria, of which 29 fulfilled quality standards. Higher microbial α-diversity, either in donors or recipients (at baseline or following FMT treatment), was associated with better clinical response rates. Engraftment of the donors' microbiota could not be clearly linked with clinical response, possibly because not every donor has an ideal microbiome. Butyrate-producing species from the Lachnospiraceae and Oscillospiraceae families were often related with response, whereas the reverse was true for Fusobacteria, many Proteobacteria, and Ruminococcus gnavus. Compositional analyses showed that clinical response is associated with a shift from a low-diversity, often Bacteroides-dominant composition to one with higher diversity, either dominated by various butyrate producers, the Christensenellaceae-Methanobrevibacter trophic network, or a moderate/high-diversity composition with abundant but not excessive levels of Prevotella copri.

CONCLUSIONS

This systematic review/meta-analysis yielded a coherent picture from a compositional perspective, which may help identify beneficial donor profiles and guide personalized FMT approaches.

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

OBJECTIVES

Clostridioides difficile infection (CDI) is the leading hospital-acquired infection in North America. While previous work on fecal microbiota transplantation (FMT), a highly effective treatment for CDI, has focused on colonization resistance mounted against C. difficile by FMT-delivered commensals, the effects of FMT on host gene expression are relatively unexplored. This study aims to identify transcriptional changes associated with FMT, particularly changes associated with protective immune responses.

METHODS

Gene expression was assessed on day 2 and day 7 after FMT in mice after antibiotic-induced dysbiosis. Flow cytometry was also performed on colon and mesenteric lymph nodes at day 7 to investigate changes in immune cell populations.

RESULTS

FMT administration after antibiotic-induced dysbiosis successfully restored microbial alpha diversity to levels of donor mice by day 7 post-FMT. Bulk RNA sequencing of cecal tissue at day 2 identified immune genes, including both pro-inflammatory and Type 2 immune pathways as upregulated after FMT. RNA sequencing was repeated on day 7 post-FMT, and expression of these immune genes was decreased along with upregulation of genes associated with restoration of intestinal homeostasis. Immunoprofiling on day 7 identified increased colonic CD45+ immune cells that exhibited dampened Type 1 and heightened regulatory and Type 2 responses. These include an increased abundance of eosinophils, alternatively activated macrophages, Th2, and T regulatory cell populations.

CONCLUSION

These results highlight the impact of FMT on host gene expression, providing evidence that FMT restores intestinal homeostasis after antibiotic treatment and facilitates tolerogenic and Type 2 immune responses.

Selenium regulates T cell differentiation in experimental autoimmune thyroiditis in mice

Selenium (Se) is an essential trace element that plays an important role in thyroid physiology. Se supplementation can reduce levels of autoimmune thyroid antibodies, which may be beneficial in Hashimoto's thyroiditis (HT). However, the long-term benefits of Se supplementation for HT patients are controversial and there is no clear clinical evidence to support it, so further basic and clinical research is needed. The effect of Se on immune cells, especially T cells, in autoimmune thyroiditis (AIT) has not been elucidated. Here, we replicated a mouse model of experimental autoimmune thyroiditis (EAT) on a high-iodine diet and treated it with Se supplementation. At week 8 of the experiment, Se supplementation reduced the destruction of thyroid follicles and the infiltration rate of lymphocytes in EAT mice, and reversed the disturbance of peripheral blood thyroxine and thyroid autoantibody levels. Further examination revealed that Se had broad effects on T-cell subsets. Its effects include reducing the production of pro-inflammatory cytokines by Th1 cells, inhibiting the differentiation and production of cytokines by Th2 and Th17 cells, and upregulating the differentiation and production of cytokines by Treg cells. These changes help alleviate thyroid follicle damage during EAT. In conclusion, selenium supplementation has the potential to improve the prognosis of AIT by altering the subset differentiation and/or function of CD4+ T cells.

Bile acids and their receptors: Potential therapeutic targets in inflammatory bowel disease

Chronic and recurrent inflammatory disorders of the gastrointestinal tract caused by a complex interplay between genetics and intestinal dysbiosis are called inflammatory bowel disease. As a result of the interaction between the liver and the gut microbiota, bile acids are an atypical class of steroids produced in mammals and traditionally known for their function in food absorption. With the development of genomics and metabolomics, more and more data suggest that the pathophysiological mechanisms of inflammatory bowel disease are regulated by bile acids and their receptors. Bile acids operate as signalling molecules by activating a variety of bile acid receptors that impact intestinal flora, epithelial barrier function, and intestinal immunology. Inflammatory bowel disease can be treated in new ways by using these potential molecules. This paper mainly discusses the increasing function of bile acids and their receptors in inflammatory bowel disease and their prospective therapeutic applications. In addition, we explore bile acid metabolism and the interaction of bile acids and the gut microbiota.

Crosstalk between Gut Microbiota and Host Immunity: Impact on Inflammation and Immunotherapy

Gut microbes and their metabolites are actively involved in the development and regulation of host immunity, which can influence disease susceptibility. Herein, we review the most recent research advancements in the gut microbiota-immune axis. We discuss in detail how the gut microbiota is a tipping point for neonatal immune development as indicated by newly uncovered phenomenon, such as maternal imprinting, in utero intestinal metabolome, and weaning reaction. We describe how the gut microbiota shapes both innate and adaptive immunity with emphasis on the metabolites short-chain fatty acids and secondary bile acids. We also comprehensively delineate how disruption in the microbiota-immune axis results in immune-mediated diseases, such as gastrointestinal infections, inflammatory bowel diseases, cardiometabolic disorders (e.g., cardiovascular diseases, diabetes, and hypertension), autoimmunity (e.g., rheumatoid arthritis), hypersensitivity (e.g., asthma and allergies), psychological disorders (e.g., anxiety), and cancer (e.g., colorectal and hepatic). We further encompass the role of fecal microbiota transplantation, probiotics, prebiotics, and dietary polyphenols in reshaping the gut microbiota and their therapeutic potential. Continuing, we examine how the gut microbiota modulates immune therapies, including immune checkpoint inhibitors, JAK inhibitors, and anti-TNF therapies. We lastly mention the current challenges in metagenomics, germ-free models, and microbiota recapitulation to a achieve fundamental understanding for how gut microbiota regulates immunity. Altogether, this review proposes improving immunotherapy efficacy from the perspective of microbiome-targeted interventions.

Specific fungi associated with response to capsulized fecal microbiota transplantation in patients with active ulcerative colitis

Objective

Fecal microbiota transplantation (FMT) is a novel microbial treatment for patients with ulcerative colitis (UC). In this study, we performed a clinical trial of capsulized FMT in UC patients to determine the association between the gut fungal community and capsulized FMT outcomes.

Design

This study recruited patients with active UC (N = 22) and healthy individuals (donor, N = 9) according to the criteria. The patients received capsulized FMT three times a week. Patient stool samples were collected before (week 0) and after FMT follow-up visits at weeks 1, 4, and 12. Fungal communities were analysed using shotgun metagenomic sequencing.

Results

According to metagenomic analysis, fungal community evenness index was greater in samples collected from patients, and the overall fungal community was clustered among the samples collected from donors. The dominant fungi in fecal samples collected from donors and patients were Ascomycota and Basidiomycota. However, capsulized FMT ameliorated microbial fungal diversity and altered fungal composition, based on metagenomic analysis of fecal samples collected before and during follow-up visits after capsulized FMT. Fungal diversity decreased in samples collected from patients who achieved remission after capsulized FMT, similar to samples collected from donors. Patients achieving remission after capsulized FMT had specific enrichment of Kazachstania naganishii, Pyricularia grisea, Lachancea thermotolerans, and Schizosaccharomyces pombe compared with patients who did not achieve remission. In addition, the relative abundance of P. grisea was higher in remission fecal samples during the follow-up visit. Meanwhile, decreased levels of pathobionts, such as Candida and Debaryomyces hansenii, were associated with remission in patients receiving capsulized FMT.

Conclusion

In the metagenomic analysis of fecal samples from donors and patients with UC receiving capsulized FMT, shifts in gut fungal diversity and composition were associated with capsulized FMT and validated in patients with active UC. We also identified the specific fungi associated with the induction of remission. ClinicalTrails.gov (NCT03426683).

Fecal microbiota transplantation in non-communicable diseases: Recent advances and protocols

Fecal microbiota transplant (FMT) is a therapeutic method that aims to restore normal gut microbial composition in recipients. Currently, FMT is approved in the USA to treat recurrent and refractory Clostridioides difficile infection and has been shown to have great efficacy. As such, significant research has been directed toward understanding the potential role of FMT in other conditions associated with gut microbiota dysbiosis such as obesity, type 2 diabetes mellitus, metabolic syndrome, neuropsychiatric disorders, inflammatory bowel disease, irritable bowel syndrome, decompensated cirrhosis, cancers and graft-versus-host disease. This review examines current updates and efficacy of FMT in treating conditions other than Clostridioides difficile infection. Further, protocols for administration of FMT are also discussed including storage of fecal samples in stool banks, inclusion/exclusion criteria for donors, fecal sample preparation and methods of treatment administration. Overall, understanding the mechanisms by which FMT can manipulate gut microbiota to provide therapeutic benefit as well as identifying potential adverse effects is an important step in clarifying its long-term safety and efficacy in treating multiple conditions in the future.

Leptin receptor antagonist attenuates experimental autoimmune thyroiditis in mice by regulating Treg/Th17 cell differentiation

Leptin has been found to be involved in the development and progression of many autoimmune diseases. As an organ-specific autoimmune disease, the pathogenesis of Hashimoto's thyroiditis has not been fully elucidated. It has been reported that serum leptin level is increased in Hashimoto's thyroiditis, but other studies have not shown any difference. We replicated a mouse model of experimental autoimmune thyroiditis (EAT) with a high-iodine diet and found that injection of the leptin receptor antagonist Allo-aca reduced thyroid follicle destruction and inflammatory cell infiltration in EAT mice, and thyroxine and thyroid autoimmune antibody levels. Further investigation revealed that Allo-aca promotes the differentiation of Treg cells and inhibits the differentiation of Th17 cells. We believe that Allo-aca can alter the differentiation of Treg/Th17 cells by inhibiting the leptin signaling pathway, thereby alleviating thyroid injury in EAT mice. Interfering with the leptin signaling pathway may be a novel new approach to treat treating and ameliorating Hashimoto's thyroiditis.