Fecal Microbiota Transplantation in Chronic Pouchitis: A Randomized, Parallel, Double-Blinded Clinical Trial

Are Small Molecules Effective in Treating Inflammatory Pouch Disorders Following Ileal Pouch-Anal Anastomosis for Ulcerative Colitis? Here Is Where We Stand

Ulcerative colitis (UC) management encompasses conventional and advanced treatments, including biological therapy and small molecules. Surgery, particularly in the form of ileal pouch-anal anastomosis (IPAA), is indicated in cases of refractory/severe disease. IPAA can lead to acute complications (e.g., acute pouchitis) as well as late complications, including chronic inflammatory disorders of the pouch. Chronic pouchitis, including the antibiotic-dependent (CADP) and antibiotic-refractory (CARP) forms, represents a significant and current therapeutic challenge due to the substantial need for evidence regarding viable treatment options. Biological therapies have shown promising results, with infliximab, adalimumab, ustekinumab, and vedolizumab demonstrating some efficacy in chronic pouchitis; however, robust randomized clinical trials are only available for vedolizumab. This narrative review focuses on the evidence concerning small molecules in chronic pouchitis, specifically Janus kinase (JAK) inhibitors and sphingosine-1-phosphate receptor (S1P-R) modulators. According to the preliminary studies and reports, Tofacitinib shows a potential effectiveness in CARP. Upadacitinib presents variable outcomes from the case series, necessitating further evaluation. Filgotinib and ozanimod demonstrate anecdotal efficacy. This review underscores the need for high-quality studies and real-world registries to develop robust guidelines for advanced therapies in post-IPAA inflammatory disorders, supported by vigilant clinical monitoring and ongoing education from international IBD specialist societies.

Key Focus Areas in Pouchitis Therapeutic Status: A Narrative Review

Pouchitis, as the most common complication after ileal pouch-anal anastomosis (IPAA), has an incidence from 7% to 46%. Pouchitis treatment still represents one of the biggest gaps of knowledge in the treatment of diseases. This review has focused on achievements and challenges in the treatment of pouchitis. A combined assessment of symptoms, endoscopic findings, histologic results, quick biomarkers, and fecal calprotectin test were determined to be valuable diagnostic criteria. Conventional therapy was described as a modification of bacterial flora, mainly with antibiotics and more recently with probiotics such as bifidobacteria, lactobacilli, and streptococci. Other therapeutic approaches such as anti-tumor necrosis factor, infliximab, adalimumab, vedolizumab, ustekinumab, tacrolimus, tofacitinib, thiopurines, corticosteroids, prolyl hydroxylase-containing enzymes, povidone-iodine, dextrose spray, fecal microbiota transplantation, herbal medicines, and leukocyte apheresis have been discussed. Changes in dietary components, and administration of complementary and alternative medicine, probiotics, and fecal transplantation in addition to conventional therapies were also shown to affect the outcome of disease. Due to the potential significant impairment in quality of life caused by pouchitis, it is essential to address the gaps in knowledge for both patients and physicians in its treatment. Therefore, well-designed and adequately powered studies should assess the optimal treatment for pouchitis.

Diet and Microbiome-Directed Therapy 2.0 for IBD

Inflammatory bowel disease (IBD) comprises chronic and relapsing disorders of the gastrointestinal tract, characterized by dysregulated immune responses to the gut microbiome. The gut microbiome and diet are key environmental factors that influence the onset and progression of IBD and can be leveraged for treatment. In this review, we summarize the current evidence on the role of the gut microbiome and diet in IBD pathogenesis, and the potential of microbiome-directed therapies and dietary interventions to improve IBD outcomes. We discuss available data and the advantages and drawbacks of the different approaches to manipulate the gut microbiome, such as fecal microbiota transplantation, next-generation and conventional probiotics, and postbiotics. We also review the use of diet as a therapeutic tool in IBD, including the effects in induction and maintenance, special diets, and exclusive enteral nutrition. Finally, we highlight the challenges and opportunities for the translation of diet and microbiome interventions into clinical practice, such as the need for personalization, manufacturing and regulatory hurdles, and the specificity to take into account for clinical trial design.

Current and future microbiome-based therapies in inflammatory bowel disease

PURPOSE OF REVIEW

The role of the microbiome and dysbiosis is increasingly recognized in the pathogenesis of inflammatory bowel disease (IBD). Intestinal microbiota transplant (IMT), previously termed fecal microbiota transplant has demonstrated efficacy in restoring a healthy microbiome and promoting gut health in recurrent Clostridioides difficile infection. Several randomized trials (RCTs) highlighted IMT's potential in treating ulcerative colitis, while smaller studies reported on its application in managing Crohn's disease and pouchitis.

RECENT FINDINGS

This review delves into the current understanding of dysbiosis in IBD, highlighting the distinctions in the microbiota of patients with IBD compared to healthy controls. It explores the mechanisms by which IMT can restore a healthy microbiome and provides a focused analysis of recent RCTs using IMT for inducing and maintaining remission in IBD. Lastly, we discuss the current knowledge gaps that limit its widespread use.

SUMMARY

The body of evidence supporting the use of IMT in IBD is growing. The lack of a standardized protocol impedes its application beyond clinical trials. Further research is needed to identify patient profile and disease phenotypes that benefit from IMT, to delineate key donor characteristics, optimize the delivery route, dosage, and frequency.

Pouchitis: pathophysiology and management

Pouchitis is an acute or chronic inflammatory disease of the ileal reservoir. It is common after restorative proctocolectomy with ileal pouch-anal anastomosis, and treatment of chronic antibiotic-refractory pouchitis has proven challenging. Most cases of acute pouchitis evolve into chronic pouchitis. The aetiology of acute pouchitis is likely to be partly related to the gut microbiota, whereas the pathophysiology of chronic pouchitis involves abnormal interactions between genetic disposition, faecal stasis, the gut microbiota, dysregulated host immunity, surgical techniques, ischaemia and mesentery-related factors. Pouchoscopy with biopsy is the most valuable modality for diagnosis, disease monitoring, assessment of treatment response, dysplasia surveillance and delivery of endoscopic therapy. Triggering or risk factors, such as Clostridioides difficile infection and use of non-steroidal anti-inflammatory drugs, should be modified or eradicated. In terms of treatment, acute pouchitis usually responds to oral antibiotics, whereas chronic antibiotic-refractory pouchitis often requires induction and maintenance therapy with integrin, interleukin or tumour necrosis factor inhibitors. Chronic pouchitis with ischaemic features, fistulae or abscesses can be treated with hyperbaric oxygen therapy.

The use of faecal microbiota transplant as treatment for recurrent or refractory Clostridioides difficile infection and other potential indications: second edition of joint British Society of Gastroenterology (BSG) and Healthcare Infection Society (HIS) guidelines

The first British Society of Gastroenterology (BSG) and Healthcare Infection Society (HIS)-endorsed faecal microbiota transplant (FMT) guidelines were published in 2018. Over the past 5 years, there has been considerable growth in the evidence base (including publication of outcomes from large national FMT registries), necessitating an updated critical review of the literature and a second edition of the BSG/HIS FMT guidelines. These have been produced in accordance with National Institute for Health and Care Excellence-accredited methodology, thus have particular relevance for UK-based clinicians, but are intended to be of pertinence internationally. This second edition of the guidelines have been divided into recommendations, good practice points and recommendations against certain practices. With respect to FMT for Clostridioides difficile infection (CDI), key focus areas centred around timing of administration, increasing clinical experience of encapsulated FMT preparations and optimising donor screening. The latter topic is of particular relevance given the COVID-19 pandemic, and cases of patient morbidity and mortality resulting from FMT-related pathogen transmission. The guidelines also considered emergent literature on the use of FMT in non-CDI settings (including both gastrointestinal and non-gastrointestinal indications), reviewing relevant randomised controlled trials. Recommendations are provided regarding special areas (including compassionate FMT use), and considerations regarding the evolving landscape of FMT and microbiome therapeutics.

The use of faecal microbiota transplant as treatment for recurrent or refractory Clostridioides difficile infection and other potential indications: second edition of joint British Society of Gastroenterology (BSG) and Healthcare Infection Society (HIS) guidelines

The first British Society of Gastroenterology (BSG) and Healthcare Infection Society (HIS)-endorsed faecal microbiota transplant (FMT) guidelines were published in 2018. Over the past 5 years, there has been considerable growth in the evidence base (including publication of outcomes from large national FMT registries), necessitating an updated critical review of the literature and a second edition of the BSG/HIS FMT guidelines. These have been produced in accordance with National Institute for Health and Care Excellence-accredited methodology, thus have particular relevance for UK-based clinicians, but are intended to be of pertinence internationally. This second edition of the guidelines have been divided into recommendations, good practice points and recommendations against certain practices. With respect to FMT for Clostridioides difficile infection (CDI), key focus areas centred around timing of administration, increasing clinical experience of encapsulated FMT preparations and optimising donor screening. The latter topic is of particular relevance given the COVID-19 pandemic, and cases of patient morbidity and mortality resulting from FMT-related pathogen transmission. The guidelines also considered emergent literature on the use of FMT in non-CDI settings (including both gastrointestinal and non-gastrointestinal indications), reviewing relevant randomised controlled trials. Recommendations are provided regarding special areas (including compassionate FMT use), and considerations regarding the evolving landscape of FMT and microbiome therapeutics.

The Progression of Microbiome Therapeutics for the Management of Gastrointestinal Diseases and Beyond

There has been an increased ability to investigate the human microbiota through next-generation sequencing and functional assessment. This advancement has rapidly expanded our ability to study and manipulate the gastrointestinal microbiome to mitigate disease. Fecal microbiota transplantation, a therapy that broadly transfers the entire intestinal ecosystem, has been explored as a potential therapeutic in a variety of gastrointestinal, hepatic, and extraintestinal conditions. The field, however, continues to evolve, with a movement toward precision microbiome therapeutics, individualizing care for various disorders. This review will describe the use of fecal microbiota transplantation, microbiota restoration, and precision microbiome therapeutics, focusing on gastrointestinal and hepatic diseases.

Normal Ileal Mucus Is Inadequate for Epithelial Protection in Ileal Pouch Mucosa

BACKGROUND

Clinical, nonspecific pouchitis is common after restorative proctocolectomy for ulcerative colitis, but its cause is unknown. A possible lack of protection for the ileal mucosa in its role as a reservoir for colonic-type bacteria may be the missing piece in defining the causes of pouchitis.

OBJECTIVE

The study aimed to review the causes of pouchitis and introduce the hypothesis that inadequate mucus protection in the pouch, combined with a predisposition to abnormal inflammation, is the most common cause of nonspecific pouchitis.

DATA SOURCES

Review of PubMed and MEDLINE for articles discussing pouchitis and intestinal mucus.

STUDY SELECTION

Studies published from 1960 to 2023. The main search terms were "pouchitis," and "intestinal mucus," whereas Boolean operators were used with multiple other terms to refine the search. Duplicates and case reports were excluded.

MAIN OUTCOME MEASURES

Current theories about the cause of pouchitis, descriptions of the role of mucus in the physiology of intestinal protection, and evidence of the effects of lack of mucus on mucosal inflammation.

RESULTS

The crossreference of "intestinal mucus" with "pouchitis" produced 9 references, none of which discussed the role of mucus in the development of pouchitis. Crossing "intestinal mucus" with "pouch" resulted in 32 articles, combining "pouchitis" with "barrier function" yielded 37 articles, and "pouchitis" with "permeability" yielded only 8 articles. No article discussed the mucus coat as a barrier to bacterial invasion of the epithelium or mentioned inadequate mucus as a factor in pouchitis. However, an ileal pouch produces a colonic environment in the small bowel, and the ileum lacks the mucus protection needed for this sort of environment. This predisposes pouch mucosa to bacterial invasion and chronic microscopic inflammation that may promote clinical pouchitis in patients prone to an autoimmune response.

LIMITATIONS

No prior studies address inadequate mucus protection and the origin of proctitis. There is no objective way of measuring the autoimmune tendency in patients with ulcerative colitis.

CONCLUSIONS

Studies of intestinal mucus in the ileal pouch and its association with pouchitis are warranted.

AGA Clinical Practice Guideline on Fecal Microbiota-Based Therapies for Select Gastrointestinal Diseases

BACKGROUND & AIMS

Fecal microbiota-based therapies include conventional fecal microbiota transplant and US Food and Drug Administration-approved therapies, fecal microbiota live-jslm and fecal microbiota spores live-brpk. The American Gastroenterological Association (AGA) developed this guideline to provide recommendations on the use of fecal microbiota-based therapies in adults with recurrent Clostridioides difficile infection; severe to fulminant C difficile infection; inflammatory bowel diseases, including pouchitis; and irritable bowel syndrome.

METHODS

The guideline was developed using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) framework to prioritize clinical questions, identify patient-centered outcomes, and conduct an evidence synthesis. The guideline panel used the Evidence-to-Decision framework to develop recommendations for the use of fecal microbiota-based therapies in the specified gastrointestinal conditions and provided implementation considerations for clinical practice.

RESULTS

The guideline panel made 7 recommendations. In immunocompetent adults with recurrent C difficile infection, the AGA suggests select use of fecal microbiota-based therapies on completion of standard of care antibiotics to prevent recurrence. In mildly or moderately immunocompromised adults with recurrent C difficile infection, the AGA suggests select use of conventional fecal microbiota transplant. In severely immunocompromised adults, the AGA suggests against the use of any fecal microbiota-based therapies to prevent recurrent C difficile. In adults hospitalized with severe or fulminant C difficile not responding to standard of care antibiotics, the AGA suggests select use of conventional fecal microbiota transplant. The AGA suggests against the use of conventional fecal microbiota transplant as treatment for inflammatory bowel diseases or irritable bowel syndrome, except in the context of clinical trials.

CONCLUSIONS

Fecal microbiota-based therapies are effective therapy to prevent recurrent C difficile in select patients. Conventional fecal microbiota transplant is an adjuvant treatment for select adults hospitalized with severe or fulminant C difficile infection not responding to standard of care antibiotics. Fecal microbiota transplant cannot yet be recommended in other gastrointestinal conditions.

Current perspectives on fecal microbiota transplantation in inflammatory bowel disease

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

Faecal Microbiota Transplantation [FMT] in the Treatment of Chronic Refractory Pouchitis: A Systematic Review and Meta-analysis

BACKGROUND

The aim of this systematic review and meta-analysis is to assess the efficacy and safety of faecal microbiota transplantation [FMT] in the treatment of chronic pouchitis.

METHODS

A PRISMA-compliant systematic review and meta-analysis was conducted using the following databases and clinical trial registers: Medline, Embase, Scopus, Cochrane Database of Systematic Reviews [CENTRAL], clinical trials.gov, ScienceDirect, and VHL [virtual health library]. The primary outcome was clinical response/remission in patients treated with FMT. Secondary outcomes included safety profile, quality of life, and changes in the gut microbiome.

RESULTS

Seven observational cohort studies/case series and two randomised, controlled trials with a total of 103 patients were included. The route, preparation, and quantity of FMT administered varied among the included studies. Clinical response rate of 42.6% with a remission rate of 29.8% was estimated in our cohort following FMT therapy. Minor, self-limiting, adverse events were reported, and the treatment was well tolerated with good short- and long-term safety profiles. Successful FMT engraftment in recipients varied and, on average, microbial richness and diversity was lower in patients with pouchitis. In some instances, shifts with specific changes towards abundance of species, suggestive of a 'healthier' pouch microbiota, were observed following treatment with FMT.

CONCLUSION

The evidence for FMT in the treatment of chronic pouchitis is sparse, which limits any recommendations being made for its use in clinical practice. Current evidence from low-quality studies suggests a variable clinical response and remission rate, but the treatment is well tolerated, with a good safety profile. This review emphasises the need for rationally designed, well-powered, randomised, placebo-controlled trials to understand the efficacy of FMT for the treatment of pouchitis.

Microbiota and mucosal gene expression of fecal microbiota transplantation or placebo treated patients with chronic pouchitis

Altered microbiota and impaired host immune function have been linked to the pathogenesis of pouchitis. We used 16S rRNA gene sequencing and RNA sequencing data from a previous randomized clinical trial (RCT) on fecal microbiota transplantation (FMT) therapy in 26 chronic pouchitis patients with one-year follow-up. We analyzed changes in both luminal and mucosal microbiota composition, as well as in host mucosal gene expression to gain insights into the host-microbiota interactions possibly underlying clinical outcomes of the patients. Antibiotic type and pattern of use were significant drivers of the luminal microbiota at baseline. Differential gene expression analysis indicated transition from ileal to colonic gene expression in the pouch, and upregulation in inflammation- and immune system-related pathways in the pouch. At 4 weeks, the non-relapsed FMT patients had a lower microbiota dissimilarity to the donor than the non-relapsed placebo patients (p = .02). While two FMT-treated patients showed a shift toward the donor's microbiota during the one-year follow-up, the overall FMT microbiota modulation effect was low. Patient's luminal and mucosal microbiota profiles were unstable in both FMT and placebo groups. Expression of the chemokine receptor CXCR4 was downregulated at 52 weeks compared to the baseline in the non-relapsed patients in both FMT and placebo groups. Microbiota modulation by FMT seems to be low in this patient group. The microbiota composition or alterations did not explain the relapse status of the patients. Some evidence for remission-related host gene expression pattern was found; specifically, CXCR4 expression may have a role in sustained remission.

Engraftment of essential functions through multiple fecal microbiota transplants in chronic antibiotic-resistant pouchitis-a case study using metatranscriptomics

BACKGROUND

Ileal pouch-anal anastomosis (IPAA) is the standard of care after total proctocolectomy for ulcerative colitis (UC). Around 50% of patients will experience pouchitis, an idiopathic inflammatory condition. Antibiotics are the backbone of treatment of pouchitis; however, antibiotic-resistant pouchitis develops in 5-10% of those patients. It has been shown that fecal microbiota transplantation (FMT) is an effective treatment for UC, but results for FMT antibiotic-resistant pouchitis are inconsistent.

METHODS

To uncover which metabolic activities were transferred to the recipients during FMT and helped the remission, we performed a longitudinal case study of the gut metatranscriptomes from three patients and their donors. The patients were treated by two to three FMTs, and stool samples were analyzed for up to 140 days.

RESULTS

Reduced expression in pouchitis patients compared to healthy donors was observed for genes involved in biosynthesis of amino acids, cofactors, and B vitamins. An independent metatranscriptome dataset of UC patients showed a similar result. Other functions including biosynthesis of butyrate, metabolism of bile acids, and tryptophan were also much lower expressed in pouchitis. After FMT, these activities transiently increased, and the overall metatranscriptome profiles closely mirrored those of the respective donors with notable fluctuations during the subsequent weeks. The levels of the clinical marker fecal calprotectin were concordant with the metatranscriptome data. Faecalibacterium prausnitzii represented the most active species contributing to butyrate synthesis via the acetyl-CoA pathway. Remission occurred after the last FMT in all patients and was characterized by a microbiota activity profile distinct from donors in two of the patients.

CONCLUSIONS

Our study demonstrates the clear but short-lived activity engraftment of donor microbiota, particularly the butyrate biosynthesis after each FMT. The data suggest that FMT triggers shifts in the activity of patient microbiota towards health which need to be repeated to reach critical thresholds. As a case study, these insights warrant cautious interpretation, and validation in larger cohorts is necessary for generalized applications. In the long run, probiotics with high taxonomic diversity consisting of well characterized strains could replace FMT to avoid the costly screening of donors and the risk of transferring unwanted genetic material. Video Abstract.

A Systematic Review and Meta-analysis of Randomized Clinical Trials on the Prevention and Treatment of Pouchitis after Ileoanal Pouch Anastomosis

BACKGROUND

This systematic review explored different medications and methods for prevention and treatment of pouchitis after restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA).

METHODS

PubMed, Scopus, and Web of Science were searched for randomized clinical trials that assessed prevention or treatment of pouchitis. The systematic review was reported in line with updated 2020 PRISMA guidelines. Risk of bias in the trials included was assessed using the ROB-2 tool and certainty of evidence was assessed using GRADE. The main outcomes were the incidence of new pouchitis episodes in the preventative studies and resolution or improvement of active pouchitis in the treatment studies.

RESULTS

Fifteen randomized trials were included. A meta-analysis of 7 trials on probiotics revealed significantly lower odds of pouchitis with the use of probiotics (RR: 0.26, 95% CI: 0.16-0.42, I2 = 20%, p < 0.001) and similar odds of adverse effects to placebo (RR: 2.43, 95% CI: 0.11-55.9, I2 = 0, p = 0.579). One trial investigated the prophylactic role of allopurinol in preventing pouchitis and found a comparable incidence of pouchitis in the two groups (31% vs 28%; p = 0.73). Seven trials assessed different treatments for active pouchitis. One recorded the resolution of pouchitis in all patients treated with ciprofloxacin versus 67% treated with metronidazole. Both budesonide enema and oral metronidazole were associated with similar significant improvement in pouchitis (58.3% vs 50%, p = 0.67). Rifaximin, adalimumab, fecal microbiota transplantation, and bismuth carbomer foam enema were not effective in treating pouchitis.

CONCLUSIONS

Probiotics are effective in preventing pouchitis after IPAA. Antibiotics, including ciprofloxacin and metronidazole, are likely effective in treating active pouchitis.

Safety and Efficacy of Fecal Microbiota Transplant in Chronic Pouchitis-A Systematic Review With Meta-Analysis

Background and Aims

Pouchitis is the most common long-term complication after ileal-pouch anal anastomosis in patients with ulcerative colitis. We conducted a systematic review and meta-analysis evaluating the safety and efficacy of fecal microbiota transplant (FMT) in chronic antibiotic dependent and refractory pouchitis.

Methods

Multiple databases were searched through April 2022 for studies that reported the efficacy and safety of FMT in patients with chronic pouchitis. Meta-analysis using random effects model was performed to calculate pooled rates.

Results

Eight studies with a total of 89 patients were included in our review, with 74 patients having received FMT and 15 patients having received placebo. The mean age ranged from 32.6 to 51.5 years. In patients that received FMT, the pooled rates of overall remission was (Pouchitis Disease Activity Index score < 7) 22% (95% CI, 9%-43%; I2, 29%), clinical remission was 20% (95% CI, 6%-49%; I2, 25%), clinical response rate was 42% (95% CI, 30%-54%; I2, 7%), and the relapse rate 60% (95% CI, 40%-77%, I2 16%) over the mean follow up of 4.67 months (range 1-12 months). The pooled proportion of patients with adverse events was 54% (95% CI, 21%-84%; I2, 73%). There were no serious adverse events or deaths.

Conclusion

In patients with chronic pouchitis, FMT is safe though there are mixed results in terms of its long-term efficacy. Future Randomized Controlled Trials with larger sample sizes and greater standardization in terms of preparation, delivery, and length of treatment of FMT are needed to determine efficacy.

ESPEN guideline on Clinical Nutrition in inflammatory bowel disease

The present guideline is an update and extension of the ESPEN scientific guideline on Clinical Nutrition in Inflammatory Bowel Disease published first in 2017. The guideline has been rearranged according to the ESPEN practical guideline on Clinical Nutrition in Inflammatory Bowel Disease published in 2020. All recommendations have been checked and, if needed, revised based on new literature, before they underwent the ESPEN consensus procedure. Moreover, a new chapter on microbiota modulation as a new option in IBD treatment has been added. The number of recommendations has been increased to 71 recommendations in the guideline update. The guideline is aimed at professionals working in clinical practice, either in hospitals or in outpatient medicine, and treating patients with IBD. General aspects of care in patients with IBD, and specific aspects during active disease and in remission are addressed. All recommendations are equipped with evidence grades, consensus rates, short commentaries and links to cited literature.

Gastrointestinal disorders and intestinal bacteria: Advances in research and applications in therapy

Intestinal bacteria coexist with humans and play a role in suppressing the invasion of pathogens, producing short-chain fatty acids, producing vitamins, and controlling the immune system. Studies have been carried out on culturable bacterial species using bacterial culture methods for many years. However, as metagenomic analysis of bacterial genes has been developed since the 1990s, it has recently revealed that many bacteria in the intestine cannot be cultured and that approximately 1,000 species and 40 trillion bacteria are present in the gut microbiota. Furthermore, the composition of the microbiota is different in each disease state compared with the healthy state, and dysbiosis has received much attention as a cause of various diseases. Regarding gastrointestinal diseases, dysbiosis has been reported to be involved in inflammatory bowel disease, irritable bowel syndrome, and non-alcoholic steatohepatitis. Recent findings have also suggested that dysbiosis is involved in colon cancer, liver cancer, pancreatic cancer, esophageal cancer, and so on. This review focuses on the relationship between the gut microbiota and gastrointestinal/hepatobiliary diseases and also discusses new therapies targeting the gut microbiota.

Hot topics on fecal microbiota transplantation for the treatment of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic intestinal mucosal inflammatory disease with complex etiology. Traditional anti-inflammatory treatment regimens have yielded unsatisfactory results. As research continues to deepen, it has been found that the gut microbiota of patients with IBD is generally altered. The presence of microorganisms in the human gastrointestinal tract is inextricably linked to the regulation of health and disease. Disruption of the microbiotic balance of microbiota in the gastrointestinal tract is called dysbiosis, which leads to disease. Therefore, in recent years, the exploration of therapeutic methods to restore the homeostasis of the gut microbiota has attracted attention. Moreover, the use of the well-established fecal microbiota transplantation (FMT) regimen for the treatment of Clostridioides difficile infection has attracted the interest of IBD researchers. Therefore, there are an increasing number of clinical studies regarding FMT for IBD treatment. However, a series of questions regarding FMT in the treatment of IBD warrants further investigation and discussion. By reviewing published studies, this review explored hot topics such as the efficacy, safety, and administration protocol flow of FMT in the treatment of IBD. Different administration protocols have generally shown reassuring results with significant efficacy and safety. However, the FMT treatment regimen needs to be further optimized. We believe that in the future, individual customized or standard FMT implementation will further enhance the relevance of FMT in the treatment of IBD.

Management of Acute and Chronic Pouchitis

BACKGROUND

Restorative proctocolectomy with IPAA is the procedure of choice when colectomy is needed for medically refractory ulcerative colitis. Pouchitis is one of the most common complications among patients who have undergone IPAA and represents a spectrum of disease varying in both phenotype and clinical course.

OBJECTIVE

This study aimed to assist clinicians and surgeons in the treatment of both acute and chronic pouchitis, including newer therapies and future directions.

DIAGNOSIS AND MANAGEMENT

Diagnosis is made by endoscopy of the pouch with biopsy because other conditions may produce similar symptoms such as increased stool frequency, abdominal cramps, and urgency. Pouchitis is classified by duration (acute versus chronic), disease pattern (infrequent, relapsing, and continuous), and response to antibiotics (responsive, dependent, and refractory). The Pouchitis Disease Activity Index may be used to measure disease activity. The management of pouchitis is guided by the disease phenotype. Acute episodes are treated with an initial 2-week course of antibiotics (typically ciprofloxacin or metronidazole), although patients with relapsing or chronic pouchitis may require long-term antibiotic treatment or the cycling of different antibiotics. Certain probiotics may also be used for maintenance therapy in those with chronic symptoms. For patients with chronic antibiotic refractory pouchitis, oral budesonide, immunosuppressive agents (azathioprine), or biologic therapy (infliximab, adalimumab, vedolizumab, and ustekinumab) may be required for both induction and maintenance with close monitoring for potential side effects. In rare cases, diverting ileostomy or pouch excision may be required.

CONCLUSION

Pouchitis represents a spectrum of disease phenotypes, ranging from acute antibiotic responsive pouchitis to chronic antibiotic refractory pouchitis. The management of pouchitis is primarily directed by the disease phenotype.

Current Trends and Challenges of Fecal Microbiota Transplantation-An Easy Method That Works for All?

The gut microbiota refers to bacteria lodges in the gastrointestinal tract (GIT) that interact through various complex mechanisms. The disturbance of this ecosystem has been correlated with several diseases, such as neurologic, respiratory, cardiovascular, and metabolic diseases and cancer. Therefore, the modulation of the gut microbiota has emerged as a potential therapeutic tool; of the various forms of gut microbiota modulation, fecal microbiota transplantation (FMT) is the most approached. This recent technique involves introducing fecal material from a healthy donor into the patient's gastrointestinal tract, aiming to restore the gut microbiota and lead to the resolution of symptoms. This procedure implies a careful donor choice, fine collection and handling of fecal material, and a balanced preparation of the recipient and consequent administration of the prepared content. Although FMT is considered a biological therapy with promising effects, side effects such as diarrhea and abdominal pain have also been claimed, making this a significant challenge in the application of FMT. Bearing this in mind, the present review aims to summarize the recent advances in understanding FMT mechanisms, their impact across different pathological conditions, and the associated side effects, emphasizing the most recent published data.

Research trends on clinical fecal microbiota transplantation: A biliometric analysis from 2001 to 2021

BACKGROUND

Numerous studies on fecal microbiota transplantation (FMT) have been conducted in the past two decades. We aimed to assess the research trends and hotspots in the field of FMT through a quantitative method.

MATERIALS AND METHODS

The clinical studies of FMT published from 2001 to 2021 were extracted from the Web of Science database. We analyzed the countries, institutions, authors, and keywords of these articles and visually illustrated using VOSviewer and CiteSpace software. The current application of FMT in clinical practice, including indications, efficacy, adverse events, as well as its methodology, such as donor, delivery route, were also evaluated.

RESULTS

A total of 227 records were finally identified. The number and rate of annual publications increased gradually. The USA ranked highest in the number of publications. Harvard University was the most influential institution, and Digestive Diseases and Sciences was the most productive journal. Kassam Zain published the most papers, and the high-frequency keywords were mainly related to diseases and techniques. Healthy donors were the most widely used donors, and frozen stool had the highest frequency of use. The predominant delivery route was endoscopy followed by oral capsules and enema. FMT was most frequently performed for the treatment of recurrent Clostridium Difficile Infection. The overall efficacy of FMT was 76.88%, and the incidence of minor and severe adverse events were 11.63% and 1.59%, respectively.

CONCLUSIONS

This study delineated a comprehensive landscape of the advancement in FMT field. Although in its infancy, FMT is a burgeoning option for the treatment of a variety of diseases associated with gut dysbiosis. To improve the efficacy and reduce adverse events, future studies are warranted to optimize the methodology of FMT.

Ileal Pouch-Anal Anastomosis and Pouchitis: The Role of the Microbiota in the Pathogenesis and Therapy

Inflammatory bowel diseases, Crohn's disease and ulcerative colitis, are life-long disorders characterized by the chronic relapsing inflammation of the gastrointestinal tract with the intermittent need for escalation treatment and, eventually, even surgery. The total proctocolectomy with ileal pouch-anal anastomosis (IPAA) is the surgical intervention of choice in subjects affected by ulcerative colitis (UC). Although IPAA provides satisfactory functional outcomes, it can be susceptible to some complications, including pouchitis as the most common. Furthermore, 10-20% of the pouchitis may develop into chronic pouchitis. The etiology of pouchitis is mostly unclear. However, the efficacy of antibiotics in pouchitis suggests that the dysbiosis of the IPAA microbiota plays an important role in its pathogenesis. We aimed to review the role of the microbiota in the pathogenesis and as a target therapy in subjects who develop pouchitis after undergoing the surgical intervention of total proctocolectomy with IPAA reconstruction.

Network meta-analysis: efficacy of treatment for acute, chronic, and prevention of pouchitis in ulcerative colitis

INTRODUCTION

Pouchitis is a clinically significant complication of ileal pouch-anal anastomosis. There is a paucity of head-to-head comparisons between treatments and no data were available about how each treatment rank against each other. A network meta-analysis of the different treatments used for acute, chronic and prevention of pouchitis was conducted.

METHODS

Biomedical databases and the Cochrane Central registry were searched between 1978 and 2021 for randomised controlled trials examining treatment for acute, chronic and prevention of pouchitis. A network meta-analysis was performed using the frequentist model with pooled relative risks and P scores used to rank treatments.

RESULTS

18 studies were included from a screen of 4291 abstracts. When compared to placebo, rifaximin was found to be the best antibiotic for acute pouchitis whereas ciprofloxacin ranked highest against metronidazole. For chronic pouchitis, metronidazole followed by probiotics was statistically significant and effective treatments in inducing remission although metronidazole had the highest adverse events. Adalimumab and bismuth were also found to be superior to placebo; however, they did not reach statistical significance. Probiotics proved superior to placebo in the prevention of pouchitis development.

CONCLUSIONS

This is the first network meta-analysis which compares the efficacy and tolerability of treatments in the management and prevention of acute and chronic pouchitis. It confirms that antimicrobial therapy remains the mainstay of treatment and adds weight to current guideline recommendations. Our results demonstrate that rifaximin and probiotics may deserve a more prominent role. While biologics are starting to show promise, large-scale head-to-head comparisons are warranted to validate the efficacy of these treatments.

Medical management of chronic pouch inflammation

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Treatment of pouchitis, Crohn's disease, cuffitis, and other inflammatory disorders of the pouch: consensus guidelines from the International Ileal Pouch Consortium

Pouchitis, Crohn's disease of the pouch, cuffitis, polyps, and extraintestinal manifestations of inflammatory bowel disease are common inflammatory disorders of the ileal pouch. Acute pouchitis is treated with oral antibiotics and chronic pouchitis often requires anti-inflammatory therapy, including the use of biologics. Aetiological factors for secondary pouchitis should be evaluated and managed accordingly. Crohn's disease of the pouch is usually treated with biologics and its stricturing and fistulising complications can be treated with endoscopy or surgery. The underlying cause of cuffitis determines treatment strategies. Endoscopic polypectomy is recommended for large, symptomatic inflammatory polyps and polyps in the cuff. The management principles of extraintestinal manifestations of inflammatory bowel disease in patients with pouches are similar to those in patients without pouches.