The role of a novel antibacterial substance,cyclic opine-producing Lacticaseibacillus rhamnosus LS8 in ameliorating ulcerative colitis:a fecal microbiota transplantation study

Intestinal microbiota imbalance may worsen the progression of ulcerative colitis(UC).Lacticaseibacillus rhamnosus LS8(LR)has the potential ability to regulate microbiota through producing a novel antibacterial substance,cyclic opine:cycloalanopine.This study aimed to investigate whether LR could ameliorate dextran sulfate sodium-induced UC in mice via modulating intestinal microbiota using fecal microbiota transplantation(FMT)experiment.The results showed that both LR and FMT attenuated UC as evidenced by 1)alleviating disease activity index and colonic pathology;2)up-regulating MUCs and tight junction proteins;3)increasing oxidative mediators and decreasing antioxidant mediators;4)down-regulating proinflammatory cytokines and chemokines.These results were mainly attributable to the microbiota-regulating effect of LR,including increasing beneficial bacteria(like Akkermansia)and its related SCFAs,while decreasing harmful bacteria(like Proteobacteria)and its related LPS,thereby suppressing the hyperactivation of TLR4/NF-κB pathway.Consequently,LR can alleviate UC and is a potential dietary supplement to attenuate UC.

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

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

Fecal microbiota transplantation for treatment of non-alcoholic fatty liver disease:Mechanism,clinical evidence,and prospect

The population of non-alcoholic fatty liver disease(NAFLD)patients along with relevant advanced liver disease is projected to continue growing,because currently no medications are approved for treatment.Fecal microbiota transplantation(FMT)is believed a novel and promising therapeutic approach based on the concept of the gut-liver axis in liver disease.There has been an increase in the number of pre-clinical and clinical studies evaluating FMT in NAFLD treatment,however,existing findings diverge on its effects.Herein,we briefly summarized the mechanism of FMT for NAFLD treatment,reviewed randomized controlled trials for evaluating its efficacy in NAFLD,and proposed the prospect of future trials on FMT.

Role of fecal microbiota transplant in management of hepatic encephalopathy: Current trends and future directions

Fecal microbiota transplantation(FMT)offers a potential treatment avenue for hepatic encephalopathy(HE)by leveraging beneficial bacterial displacement to restore a balanced gut microbiome.The prevalence of HE varies with liver disease severity and comorbidities.HE pathogenesis involves ammonia toxicity,gut-brain communication disruption,and inflammation.FMT aims to restore gut microbiota balance,addressing these factors.FMT's efficacy has been explored in various conditions,including HE.Studies suggest that FMT can modulate gut microbiota,reduce ammonia levels,and alleviate inflammation.FMT has shown promise in alcohol-associated,hepatitis B and C-associated,and non-alcoholic fatty liver disease.Benefits include improved liver function,cognitive function,and the slowing of disease progression.However,larger,controlled studies are needed to validate its effectiveness in these contexts.Studies have shown cognitive improvements through FMT,with potential benefits in cirrhotic patients.Notably,trials have demonstrated reduced serious adverse events and cognitive enhancements in FMT arms compared to the standard of care.Although evidence is promising,challenges remain:Limited patient numbers,varied dosages,administration routes,and donor profiles.Further large-scale,controlled trials are essential to establish standardized guidelines and ensure FMT's clinical applications and efficacy.While FMT holds potential for HE management,ongoing research is needed to address these challenges,optimize protocols,and expand its availability as a therapeutic option for diverse hepatic conditions.

Fecal microbiota transplantation for the treatment of irritable bowel syndrome:A systematic review and meta-analysis

BACKGROUND Irritable bowel syndrome(IBS)is the most prevalent gastrointestinal disorder in developed countries and reduces patients’quality of life,hinders their ability to work,and increases health care costs.A growing number of trials have demonstrated an aberrant gut microbiota composition in IBS,also known as‘gut dysbiosis’.Fecal microbiota transplantation(FMT)has been suggested as a treatment for IBS.AIM To assess the efficacy and safety of FMT for the treatment of IBS.METHODS We searched Cochrane Central,MEDLINE,EMBASE and Web of Science up to 24 October 2022 for randomised controlled trials(RCTs)investigating the effectiveness of FMT compared to placebo(including autologous FMT)in treating IBS.The primary outcome was the number of patients with improvements of symptoms measured using a validated,global IBS symptoms score.Secondary outcomes were changes in quality-of-life scores,non-serious and serious adverse events.Risk ratios(RR)and corresponding 95%CI were calculated for dichotomous outcomes,as were the mean differences(MD)and 95%CI for continuous outcomes.The Cochrane risk of bias tool was used to assess the quality of the trials.GRADE criteria were used to assess the overall quality of the evidence.RESULTS Eight RCTs(484 participants)were included in the review.FMT resulted in no significant benefit in IBS symptoms three months after treatment compared to placebo(RR 1.19,95%CI:0.68-2.10).Adverse events were reported in 97 participants in the FMT group and in 45 participants in the placebo group(RR 1.17,95%CI:0.63-2.15).One serious adverse event occurred in the FMT group and two in the placebo group(RR 0.42,95%CI:0.07-2.60).Endoscopic FMT delivery resulted in a significant improvement in symptoms,while capsules did not.FMT did not improve the quality of life of IBS patients but,instead,appeared to reduce it,albeit non significantly(MD-6.30,95%CI:-13.39-0.79).The overall quality of the evidence was low due to moderate-high inconsistency,the small number of patients in the studies,and imprecision.CONCLUSION We found insufficient evidence to support or refute the use of FMT for IBS.Larger trials are needed.

Fecal microbiota transplantation in patients with metabolic syndrome and obesity:A randomized controlled trial

BACKGROUND Metabolic syndrome is a multifactorial disease,and the gut microbiota may play a role in its pathogenesis.Obesity,especially abdominal obesity,is associated with insulin resistance,often increasing the risk of type two diabetes mellitus,vascular endothelial dysfunction,an abnormal lipid profile,hypertension,and vascular inflammation,all of which promote the development of atherosclerotic cardiovascular disease.AIM To evaluate the outcomes of fecal microbiota transplantation(FMT)in patients with metabolic syndrome.METHODS This was a randomized,single-blind placebo-controlled trial comparing FMT and a sham procedure in patients with metabolic syndrome.We selected 32 female patients,who were divided into eight groups of four patients each.All of the patients were submitted to upper gastrointestinal endoscopy.In each group,two patients were randomly allocated to undergo FMT,and the other two patients received saline infusion.The patients were followed for one year after the procedures,during which time anthropometric,bioimpedance,and biochemical data were collected.The patients also had periodic consultations with a nutritionist and an endocrinologist.The primary end point was a change in the gut microbiota.RESULTS There was evidence of a postprocedural change in microbiota composition in the patients who underwent FMT in relation to that observed in those who underwent the sham procedure.However,we found no difference between the two groups in terms of the clinical parameters evaluated.CONCLUSION There were no significant differences in biochemical or anthropometric parameters,between the two groups evaluated.Nevertheless,there were significant postprocedural differences in the microbiota composition between the placebo group.To date,clinical outcomes related to FMT remain uncertain.

Fecal microbiota transplantation alleviates experimental colitis through the Toll-like receptor 4 signaling pathway

BACKGROUND Fecal microbiota transplantation(FMT)has shown promising therapeutic effects on mice with experimental colitis and patients with ulcerative colitis(UC).FMT modulates the Toll-like receptor 4(TLR4)signaling pathway to treat some other diseases.However,it remains unknown whether this modulation is also involved in the treatment of UC.AIM To clarify the necessity of TLR4 signaling pathway in FMT on dextran sodium sulphate(DSS)-induced mice and explain the mechanism of FMT on UC,through association analysis of gut microbiota with colon transcriptome in mice.METHODS A mouse colitis model was constructed with wild-type(WT)and TLR4-knockout(KO)mice.Fecal microbiota was transplanted by gavage.Colon inflammation severity was measured by disease activity index(DAI)scoring and hematoxylin and eosin staining.Gut microbiota structure was analyzed through 16S ribosomal RNA sequencing.Gene expression in the mouse colon was obtained by transcriptome sequencing.RESULTS The KO(DSS+Water)and KO(DSS+FMT)groups displayed indistinguishable body weight loss,colon length,DAI score,and histology score,which showed that FMT could not inhibit the disease in KO mice.In mice treated with FMT,the relative abundance of Akkermansia decreased,and Lactobacillus became dominant.In particular,compared with those in WT mice,the scores of DAI and colon histology were clearly decreased in the KO-DSS group.Microbiota structure showed a significant difference between KO and WT mice.Akkermansia were the dominant genus in healthy KO mice.The ineffectiveness of FMT in KO mice was related to the decreased abundance of Akkermansia.Gene Ontology enrichment analysis showed that differentially expressed genes between each group were mainly involved in cytoplasmic translation and cellular response to DNA damage stimulus.The top nine genes correlating with Akkermansia included Aqp4,Clca4a,Dpm3,Fau,Mcrip1,Meis3,Nupr1 L,Pank3,and Rps13(|R|>0.9,P<0.01).CONCLUSION FMT may ameliorate DSS-induced colitis by regulating the TLR4 signaling pathway.TLR4 modulates the composition of gut microbiota and the expression of related genes to ameliorate colitis and maintain the stability of the intestinal environment.Akkermansia bear great therapeutic potential for colitis.

Fecal microbiota transplantation as potential first-line treatment for patients with Clostridioides difficile infection and prior appendectomy

Clostridioides difficile infection(CDI)is a global health problem.The association of appendectomy on the severity and prognosis of CDI has been reported in many literatures,but there are still contradictions.In a retrospective study entitled“Patients with Closterium diffuse infection and prior appendectomy may be prone to word outcomes”published in World J Gastrointest Surg 2021,the author found that prior appendectomy affects the severity of CDI.Appendectomy may be a risk factor for increasing the severity of CDI.Therefore,it is necessary to seek alternative treatment for patients with prior appendectomy when they are more likely to have severe or fulminant CDI.

Fecal microbiota transplantation ameliorates experimental colitis via gut microbiota and T-cell modulation

BACKGROUND Emerging evidence has demonstrated that fecal microbiota transplantation(FMT)has a promising therapeutic effect on mice with experimental colitis and patients with ulcerative colitis(UC),although the mechanism of FMT is unclear.AIM To evaluate the protective effect of FMT on UC and clarify its potential dependence on the gut microbiota,through association analysis of gut microbiota with colon transcriptome in mice.METHODS Dextran sodium sulfate(DSS)-induced experimental colitis was established and fecal microbiota was transplanted by gavage.Severity of colon inflammation was measured by body weight,disease activity index,colon length and histological score.Gut microbiota alteration was analyzed through 16S ribosomal ribonucleic acid sequencing.The differentially expressed genes(DEGs)in the colon were obtained by transcriptome sequencing.The activation status of colonic T lymphocytes in the lamina propria was evaluated by flow cytometry.RESULTS Compared with the DSS group,the weight loss,colon length shortening and inflammation were significantly alleviated in the FMT group.The scores of disease activity index and colon histology decreased obviously after FMT.FMT restored the balance of gut microbiota,especially by upregulating the relative abundance of Lactobacillus and downregulating the relative abundance of Clostridium_sensu_stricto_1 and Turicibacter.In the transcriptomic analysis,128 DEGs intersected after DSS treatment and FMT.Functional annotation analysis suggested that these DEGs were mainly involved in T-lymphocyte activation.In the DSS group,there was an increase in colonic T helper CD4^(+)and T cytotoxic CD8^(+)cells by flow cytometry.FMT selectively downregulated the ratio of colonic CD4^(+)and CD8^(+)T cells to maintain intestinal homeostasis.Furthermore,Clostri dium_sensu_stricto_1 was significantly related to inflammation-related genes including REG3G,CCL8 and IDO1.CONCLUSION FMT ameliorated DSS-induced colitis in mice via regulating the gut microbiota and T-cell modulation.

Fecal microbiota transplantation in the metabolic diseases:Current status and perspectives

With the development of microbiology and metabolomics,the relationship between the intestinal microbiome and intestinal diseases has been revealed.Fecal microbiota transplantation(FMT),as a new treatment method,can affect the course of many chronic diseases such as metabolic syndrome,malignant tumor,autoimmune disease and nervous system disease.Although the mechanism of action of FMT is now well understood,there is some controversy in metabolic diseases,so its clinical application may be limited.Microflora transplantation is recommended by clinical medical guidelines and consensus for the treatment of recurrent or refractory Clostridium difficile infection,and has been gradually promoted for the treatment of other intestinal and extraintestinal diseases.However,the initial results are varied,suggesting that the heterogeneity of the donor stools may affect the efficacy of FMT.The success of FMT depends on the microbial diversity and composition of donor feces.Therefore,clinical trials may fail due to the selection of ineffective donors,and not to faulty indication selection for FMT.A new understanding is that FMT not only improves insulin sensitivity,but may also alter the natural course of type 1 diabetes by modulating autoimmunity.In this review,we focus on the main mechanisms and deficiencies of FMT,and explore the optimal design of FMT research,especially in the field of cardiometabolic diseases.

Microbiota shaping — the effects of probiotics, prebiotics, and fecal microbiota transplant on cognitive functions: A systematic review

BACKGROUND Dementia is a chronic progressive neurological disease affecting millions of people worldwide,and represents a relevant economic burden for healthcare systems.Although its pathogenesis is still unknown,recent findings have reported that a dysregulated gut-brain axis communication,a fundamental relationship mediated by several host and microbial molecules,is associated with cognitive disorders.In addition,gut microbiota manipulation reduces neuroinflammation,improving cognitive function by restoring the functional gut-brain axis.AIM To better define the effects of probiotics,prebiotics,synbiotics,and fecal microbiota transplant(FMT)on cognitive function.METHODS We performed a literature search of human randomized clinical trials to examine the effects of the administration of probiotics,prebiotics,synbiotics,or FMT on cognition outcomes in healthy or sick people of every age,sex,and nationality.We systematically searched Embase,Medline/PubMed,Cochrane Library,central and clinicaltrials.gov databases with a combination of comprehensive terms related to cognition and gut microbiota manipulation.Then we carefully reviewed and synthesized the data by type of study design and setting,characteristics of the studied population,kind of intervention(strain type or mixture type,dosage,and frequency of administration),control treatment,inclusion and exclusion criteria,follow-up duration,and cognitive or memory outcomes.RESULTS After examining the titles and abstracts,the initial literature screening identified 995 articles,but we added 23 papers in our systematic review.The analyses of these selected studies highlighted that both probiotic supplementation and FMT improved cognitive function regardless of the type and posology of administration and the adopted cognitive tests and questionnaires.We found that most of the studies conducted in healthy people showed a significant positive effect of the intervention on at least one of the performed cognitive tests.Regarding unhealthy subjects,while FMT and especially probiotic administration had multiple beneficial effects on different cognitive functions,supplementation with prebiotics did not provide any cognitive improvement.CONCLUSION Probiotic supplementation and FMT may represent a promising strategy to restore gut eubiosis and enhance the cognitive functions of healthy people and patients with neurological disorders.

Awareness and attitude of fecal microbiota transplantation through transendoscopic enteral tubing among inflammatory bowel disease patients

BACKGROUND Transendoscopic enteral tubing(TET)has been used in China as a novel delivery route for fecal microbiota transplantation(FMT)into the whole colon with a high degree of patient satisfaction among adults.AIM To explore the recognition and attitudes of FMT through TET in patients with inflammatory bowel disease(IBD).METHODS An anonymous questionnaire,evaluating their awareness and attitudes toward FMT and TET was distributed among IBD patients in two provinces of Eastern and Southwestern China.Question formats included single-choice questions,multiple-choice questions and sorting questions.Patients who had not undergone FMT were mainly investigated for their cognition and acceptance of FMT and TET.Patients who had experience of FMT,the way they underwent FMT and acceptance of TET were the main interest.Then all the patients were asked whether they would recommend FMT and TET.This study also analyzed the preference of FMT delivery in IBD patients and the patient-related factors associated with it.RESULTS A total of 620 eligible questionnaires were included in the analysis.The survey showed that 44.6%(228/511)of patients did not know that FMT is a therapeutic option in IBD,and 80.6%(412/511)of them did not know the concept of TET.More than half(63.2%,323/511)of the participants stated that they would agree to undergo FMT through TET.Of the patients who underwent FMT via TET[62.4%(68/109)],the majority[95.6%(65/68)]of them were satisfied with TET.Patients who had undergone FMT and TET were more likely to recommend FMT than patients who had not(94.5%vs 86.3%,P=0.018 and 98.5%vs 87.8%,P=0.017).Patients’choice for the delivery way of FMT would be affected by the type of disease and whether the patient had the experience of FMT.When compared to patients without experience of FMT,Crohn’s disease and ulcerative colitis patients who had experience of FMT preferred mid-gut TET(P<0.001)and colonic TET(P<0.001),respectively.CONCLUSION Patients’experience of FMT through TET lead them to maintain a positive attitude towards FMT.The present findings highlighted the significance of patient education on FMT and TET.

Fecal microbiota transplantation against irritable bowel syndrome?Rigorous randomized clinical trials are required

Halkj?r et al searched systematically nine articles including 48 patients, and concluded that fecal microbiota transplantation(FMT) can be an ideal treatment option for irritable bowel syndrome(IBS) subjects. Regardless of the few successes in current traditional therapies(change in diet, herbal medicine and antibiotics) in IBS, a sharp increase in interests in the FMT option has been reported in the current century. However, there is a long list of unclear issues concerning the application of FMT for the treatment of IBS. Route of delivery and optimum dosage are the major concerns to consider before using in clinical practice.

Immunological mechanisms of fecal microbiota transplantation in recurrent Clostridioides difficile infection

Fecal microbiota transplantation(FMT)is a successful method for treating recurrent Clostridioides difficile(C.difficile)infection(rCDI)with around 90%efficacy.Due to the relative simplicity of this approach,it is being widely used and currently,thousands of patients have been treated with FMT worldwide.Nonetheless,the mechanisms underlying its effects are just beginning to be understood.Data indicate that FMT effectiveness is due to a combination of microbiological direct mechanisms against C.difficile,but also through indirect mechanisms including the production of microbiota-derived metabolites as secondary bile acids and short chain fatty acids.Moreover,the modulation of the strong inflammatory response triggered by C.difficile after FMT seems to rely on a pivotal role of regulatory T cells,which would be responsible for the reduction of several cells and soluble inflammatory mediators,ensuing normalization of the intestinal mucosal immune system.In this minireview,we analyze recent advances in these immunological aspects associated with the efficacy of FMT.

Preclinical safety,effectiveness evaluation,and screening of functional bacteria for fecal microbiota transplantation based on germ-free animals

Fecal microbiota transplantation(FMT),also known as fecal bacterial therapy,is a treatment option that can quickly reconstruct the normal composition of intestinal microbes,and it has a good therapeutic effect on Clostridium difficile infection,as well as on other microecological disorders.However,the causal mechanism of FMT efficacy remains to be clarified,its safety is a major problem,and the standardization and acceptability of FMT need to be improved.This review summarizes its current research status and potential research areas that need to be strengthened,and proposes to clarify the safety of FMT and the causal relationship between FMT and therapeutic effectiveness based on germ-free animals.Meanwhile,the research system is combined with multiomics technology to screen the effective bacteria in FMT,and develop standard,safe,effective and controllable flora of FMT.

Fecal microbiota transplant for more than Clostridioides difficile: Dermatology a new frontier

Fecal microbiota transplant(FMT)has quickly become popular in research not only for recurrent Clostridioides difficile infections but for other chronic conditions as well.Recent,small dermatologic studies have reported improvements in inflammatory skin conditions in individuals treated with FMT,but larger studies are needed to clarify this possible relationship between the skin and the gut microbiome.We conducted a single-center,retrospective chart review to assess changes in acne,dermatitis herpetiformis and/or celiac disease,eczema,and psoriasis.Due to the retrospective nature of this study and the limitations of the current electronic medical record,we were unable to adequately assess cases of these diseases in relation to FMT.However,this study informs us that improvements in retrospective data are needed to formally evaluate this possible association.The better,but more cumbersome,study design would be a prospective,observational study.We encourage others to pursue further interdepartmental research on the influence of the gut microbiome on inflammatory skin diseases.

Fecal microbiota transplant and dermatologic disorders:A retrospective cohort study assessing the gut microbiome’s role in skin disease

BACKGROUND There is indication that fecal microbiota transplant(FMT)has the potential to alter the course of chronic skin disease,but few studies have investigated this phenomenon beyond case reports.Research with larger sample sizes is needed to provide a more thorough assessment of possible associations and to establish a broader foundation upon which to base hypotheses.AIM To identify associations between FMT and skin conditions,particularly infectious and inflammatory etiologies,and the role of dermatology post-FMT.METHODS We conducted a retrospective cohort study involving a chart review of all patients whom received FMT between January 2013 and December 2019 at a single academic medical center.Dermatologic follow-up was assessed for the two years after FMT or through March 2020 for more recent procedures.Dermatologic diagnoses and visits within the study time frame were recorded and assessed for trends.This study was exploratory in nature.Descriptive statistics were calculated,and the t-test,Pearson’s chi-squared test,and Fisher’s exact test were used to calculate P values.RESULTS Median age was 38(range,17-90).In total,109 patients who underwent 111 fecal microbiota transplant events were included.Twenty-six events(23.4%)involved a dermatology office visit post-procedure,and of these events,20 out of the 26(76.9%)had an infectious or inflammatory skin condition.The mean time to first visit was 10.0(±7.0)mo.The most common diagnoses were dermatophyte,wart(s),and dermatitis,though no specific diagnoses predominated in a way indicating FMT had a significant impact.More patients with a post-FMT skin disease diagnosis had a history of Crohn’s disease compared to those without(P=0.022),but results could be affected by a small sample size.CONCLUSION Our study is limited by its retrospective nature,but the findings allow a glimpse at dermatologic conditions post-FMT.Few significant associations were found,but potential associations between FMT and skin disease should be further investigated,preferably in prospective studies,to identify how FMT might be of use for treating infectious and inflammatory skin diseases.

Microbiota-gut-brain axis and major depressive disorder:implications for fecal microbiota transplantation therapy

Major depression disorder(MDD),which can affect individuals of any age,is one of the most common diseases,affecting an estimated 350 million people worldwide and placing a significant burden on individuals and society.MDD is heterogeneous.The conventional antidepressants are only partially effective and only 44%of patients are in remission during treatment.Therefore,improving the efficacy of MDD therapy has become a key research focus.An increasing number of studies have shown that the microbiota-gut-brain axis is closely related to the physiological and pathological processes of depression,suggesting that the gut microbiota may have protective or pathogenic effects on the development of MDD.Gut microbiota-oriented treatment is one of the most promising approaches.Fecal microbiota transplantation(FMT)has great potential to improve MDD more directly and effectively,although few research results in this area has been conducted.To assess the gut microbiota's connection with MDD,the efficiency of the nodes and the prospects of FMT therapy for MDD have been reviewed in this paper.

Improvement of Clinical Symptoms and Gut Microbiome After Fecal Microbiota Transplantation:A Case Study of a 106-Year-Old Man with MODS

Fecal microbiota transplantation(FMT)has been used in a wide variety of diseases.Many researchers hypothesize that the dysbiosis of intestinal microbiota plays an important role in the development of gut-derived infections;thus,FMT is a potential therapeutic target against multiple organ dysfunction syndrome(MODS).A 106-year-old male patient was initially diagnosed with cerebral infarction and pulmonary infection.During the course of hospitalization,the patient developed MODS.The patient received a single nasogastric infusion of sterile-filtered,pathogen-free feces from a healthy donor.Fecal samples were collected every two days post-infusion to monitor changes in the microbiota composition in response to treatment.After FMT,MODS and severe diarrhea were alleviated;the patient’s fecal microbiome diversity resembled that of the healthy donor’s fecal microbiome;moreover,his clinical symptoms improved remarkably with the changes in fecal microbiome.Additionally,no observable side effects were noted during FMT treatment.These findings warrant further investigation of FMT as a putative new therapy for treating microbiota-related diseases,such as MODS.

Relationship between intestinal microbiota and ulcerative colitis:Mechanisms and clinical application of probiotics and fecal microbiota transplantation

Ulcerative colitis(UC) is an inflammatory disease that mainly affects the colon and rectum. It is believed that genetic factors, host immune system disorders, intestinal microbiota dysbiosis, and environmental factors contribute to the pathogenesis of UC. however, studies on the role of intestinal microbiota in the pathogenesis of UC have been inconclusive. Studies have shown that probiotics improve intestinal mucosa barrier function and immune system function and promote secretion of anti-inflammatory factors, thereby inhibiting the growth of harmful bacteria in the intestine. Fecal microbiota transplantation(FMT) can reduce bowel permeability and thus the severity of disease by increasing the production of short-chain fatty acids, especially butyrate, which help maintain the integrity of the epithelial barrier. FMT can also restore immune dysbiosis by inhibiting Th1 differentiation, activity of T cells, leukocyte adhesion, and production of inflammatory factors. Probiotics and FMT are being increasingly used to treat UC, but their use is controversial because of uncertain efficacy. Here, we briefly review the role of intestinal microbiota in thepathogenesis and treatment of UC.