Fecal microbiota transplant for Crohn disease: A study evaluating safety, efficacy, and microbiome profile

Exploring the Gut Microbiome's Role in Inflammatory Bowel Disease: Insights and Interventions

Inflammatory Bowel Disease (IBD), encompassing Crohn's disease (CD) and ulcerative colitis (UC), is a chronic and relapsing inflammatory condition of the intestine that significantly impairs quality of life and imposes a heavy burden on healthcare systems globally. While the exact etiology of IBD is unclear, it is influenced by genetic, environmental, immunological, and microbial factors. Recent advances highlight the gut microbiome's pivotal role in IBD pathogenesis. The microbial dysbiosis characteristic of IBD, marked by a decline in beneficial bacteria and an increase in pathogenic microbes, suggests a profound connection between microbial imbalance and disease mechanisms. This review explores diagnostic approaches to IBD that integrate clinical assessment with advanced microbiological analyses, highlighting the potential of microbiome profiling as a non-invasive diagnostic tool. In addition, it evaluates conventional and emerging treatments and discusses microbiome-targeted intervention prospects, such as probiotics, symbiotics, and faecal microbiota transplantation. The necessity for future research to establish their efficacy and safety is emphasised.

Gut microbiome, metabolome, host immunity associated with inflammatory bowel disease and intervention of fecal microbiota transplantation

Gut dysbiosis has been associated with inflammatory bowel disease (IBD), one of the most common gastrointestinal diseases. The microbial communities play essential roles in host physiology, with profound effects on immune homeostasis, directly or via their metabolites and/or components. There are increasing clinical trials applying fecal microbiota transplantation (FMT) with Crohn's disease (CD) and ulcerative colitis (UC). The restoration of dysbiotic gut microbiome is considered as one of the mechanisms of FMT therapy. In this work, latest advances in the alterations in gut microbiome and metabolome features in IBD patients and experimental mechanistic understanding on their contribution to the immune dysfunction were reviewed. Then, the therapeutic outcomes of FMT on IBD were summarized based on clinical remission, endoscopic remission and histological remission of 27 clinical trials retrieved from PubMed which have been registered on ClinicalTrials.gov with the results been published in the past 10 years. Although FMT is established as an effective therapy for both subtypes of IBD, the promising outcomes are not always achieved. Among the 27 studies, only 11 studies performed gut microbiome profiling, 5 reported immune response alterations and 3 carried out metabolome analysis. Generally, FMT partially restored typical changes in IBD, resulted in increased α-diversity and species richness in responders and similar but less pronounced shifts of patient microbial and metabolomics profiles toward donor profiles. Measurements of immune responses to FMT mainly focused on T cells and revealed divergent effects on pro-/anti-inflammatory functions. The very limited information and the extremely confounding factors in the designs of the FMT trials significantly hindered a reasonable conclusion on the mechanistic involvement of gut microbiota and metabolites in clinical outcomes and an analysis of the inconsistencies.

Long-Term Efficacy and Safety of Fecal Microbiota Transplantation for C. difficile Infections Across Academic and Private Clinical Settings

PURPOSE

Fecal microbiota transplant (FMT) is increasingly performed for Clostridioides difficile infection (CDI), although long-term efficacy and safety data are limited and are focused on results from academic medical centers rather than private settings where most patients receive care.

METHODS

Medical records of 165 patients who received FMTs for CDI were reviewed from an academic medical center and an adjacent, unaffiliated private practice. Of these patients, 68 also completed a survey regarding their long-term disease course and interval health.

RESULTS

CDI resolution occurred in 81.3% (100/123) at the academic center and 95.2% (40/42) in the private setting. Private practice patients were more likely to present with recurrent, rather than refractory, CDI (92.9% vs. 66.7% P <0.001). Those from the academic center were more likely to have comorbid IBD, recent hospitalization, recent proton pump inhibitor use, ongoing immunosuppression, and inpatient FMT (all P values <0.05).Among surveyed patients, 29.4% developed interval comorbidities or changes to pre-existing conditions after a median follow-up of 33.7 months (IQR 13.2 to 44.3 mo). Of 30 patients requiring subsequent antibiotics, 13.3% suffered CDI relapse. All subjects who had initially responded to FMT but had a subsequent CDI (17.9%, 10/56) responded to another FMT.

CONCLUSIONS

In a real-world setting, patients who underwent FMT at academic centers differed significantly in clinical characteristics from those treated at a private practice. In both settings, FMT is an effective treatment for CDI not responding to standard therapies, even after subsequent antibiotic use. New diagnoses following FMT, however, are common and merit further exploration.

Swiss expert opinion: current approaches in faecal microbiota transplantation in daily practice

INTRODUCTION

Faecal microbiota transplantation (FMT) is an established therapy for recurrent C. difficile infection, and recent studies have reported encouraging results of FMT in patients with ulcerative colitis. Few international consensus guidelines exist for this therapy, and thus FMT policies and practices differ among European countries. As of 2019, stool transplants are considered a non-standardised medicinal product in Switzerland, and a standardised production process requires authorisation by the Swiss Agency for Therapeutic Products. This authorisation leads to prolonged administrative procedures and increasing costs, which reduces treatment accessibility. In particular, patients with ulcerative colitis in Switzerland can only benefit from FMT off-label, even though it is a valid therapeutic option. Therefore, this study summarised the available data on FMT and established a framework for the standardised use of FMT.

METHODS

A panel of Swiss gastroenterologists with a special interest in inflammatory bowel disease was established to identify the current key issues of FMT. After a comprehensive review of the literature, statements were formulated about FMT indications, donor screening, stool transplant preparation and administration, and safety aspects. The panel then voted on the statements following the Delphi process; the statements were reformulated and revoted until a consensus was reached. The manuscript was then reviewed by an infectiologist (the head of Lausanne's FMT centre).

RESULTS

The established statements are summarised in the supplementary tables in the appendix to this paper. The working group hopes these will help standardise FMT practice in Switzerland and contribute to making faecal microbiota transplantation a safe and accessible treatment for patients with recurrent C. difficile infections and selected patients with ulcerative colitis, as well as other indications in the future.

Fecal microbiota transplantation for induction of remission in Crohn's disease: a systematic review and meta-analysis

PURPOSE

Fecal microbiota transplantation (FMT) has been found to be a potential treatment for Crohn's disease (CD). We sought to perform a systematic review and meta-analysis to evaluate the efficacy and safety of FMT in CD.

METHODS

Electronic databases were searched for studies until January 2023. Clinical remission was established as the primary outcome. The secondary outcome was clinical response, endoscopic remission, minor adverse events, serious adverse events, and changes in disease activity indices, biochemical indicators, and microbial diversities. Pooled effect sizes and 95% confidence intervals (CIs) were calculated under the random effects model.

RESULTS

Eleven cohort studies and one randomized controlled trial involving 228 patients were included. In a meta-analysis, the pooled proportion of adult patients with active CD that achieved clinical remission 2 to 4 weeks after FMT was 57% (95% CI = 49-64%) with a low risk of heterogeneity (I² = 37%). Furthermore, our results showed that FMT significantly (standardized mean difference = -0.66; 95% CI = -1.12 to -0.20; I² = 0) reduced Crohn's disease activity index scores 4 to 8 weeks after FMT. Subgroup analyses showed no difference between FMT methodologies, except for pre-FMT treatment with antibiotics (P = 0.02). Most adverse events were self-limiting and disappeared spontaneously within hours or days after FMT. Microbiota analysis showed an increased Shannon diversity and a shift toward donor-like microbiome after FMT.

CONCLUSION

FMT could be a promising therapy in the short-term treatment of active CD. More placebo-controlled randomized trials with a long-term follow-up treatment are necessary.

TRIAL REGISTRATION

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022322694 No. CRD42022322694.

Mild Crohn's Disease: Definition and Management

PURPOSE OF REVIEW

Crohn's Disease (CD) is a chronic inflammatory disease that can lead to progressive damage to the gastrointestinal tract and significant disability. Early, "top-down" biologic therapy is recommended in moderate-to-severe CD to induce remission and to prevent hospitalization and complications. However, an estimated 20-30% of patients with CD have a mild disease course and may not garner sufficient benefit from expensive, immunosuppressing agents to justify their risks. Herein, we review characteristics of patients with mild CD, the available options for disease treatment and monitoring, and future directions of research.

RECENT FINDINGS

For ambulatory outpatients with low-risk, mild, ileal or ileocolonic CD, induction of remission with budesonide is recommended. For colonic CD, sulfasalazine is a reasonable choice, although other aminosalicylates have no role in the treatment of CD. No large, randomized trial has supported the use of antibiotics or antimycobacterials in the treatment of CD. Partial Enteral Nutrition and Crohn's Disease Exclusion Diets may be appropriate for inducing remission in some adult patients, with trials ongoing. Select patients with mild-to-moderate CD may benefit from maintenance therapy with azathioprines or gut specific biologics, such as vedolizumab. The role of complementary and alternative medicine is not well defined. The identification, risk stratification, and monitoring of patients with mild CD can be a challenging clinical scenario. Some patients with low risk of disease progression may be appropriate for initial induction of remission with budesonide or sulfasalazine, followed by close clinical monitoring. Future research should focus on pre-clinical biomarkers to stratify disease, novel therapies with minimal systemic immune suppression, and validation of rigorous clinical monitoring algorithms.

Immunometabolism and microbial metabolites at the gut barrier: Lessons for therapeutic intervention in inflammatory bowel disease

The concept of immunometabolism has emerged recently whereby the repolarizing of inflammatory immune cells toward anti-inflammatory profiles by manipulating cellular metabolism represents a new potential therapeutic approach to controlling inflammation. Metabolic pathways in immune cells are tightly regulated to maintain immune homeostasis and appropriate functional specificity. Because effector and regulatory immune cell populations have different metabolic requirements, this allows for cellular selectivity when regulating immune responses based on metabolic pathways. Gut microbes have a major role in modulating immune cell metabolic profiles and functional responses through extensive interactions involving metabolic products and crosstalk between gut microbes, intestinal epithelial cells, and mucosal immune cells. Developing strategies to target metabolic pathways in mucosal immune cells through the modulation of gut microbial metabolism has the potential for new therapeutic approaches for human autoimmune and inflammatory diseases, such as inflammatory bowel disease. This review will give an overview of the relationship between metabolic reprogramming and immune responses, how microbial metabolites influence these interactions, and how these pathways could be harnessed in the treatment of inflammatory bowel disease.

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.

Metagenomic and bile acid metabolomic analysis of fecal microbiota transplantation for recurrent Clostridiodes difficile and/or inflammatory bowel diseases

BACKGROUND

Fecal microbiota transplantation (FMT) is an effective treatment of recurrent Clostridioides difficile infections (rCDI), but has more limited efficacy in treating either ulcerative colitis (UC) or Crohn's disease (CD), two major forms of inflammatory bowel diseases (IBD). We hypothesize that FMT recipients with rCDI and/or IBD have baseline fecal bile acid (BA) compositions that differ significantly from that of their healthy donors and that FMT will normalize the BA compositions.

AIM

To study the effect of single colonoscopic FMT on microbial composition and function in four recipient groups: 1.) rCDI patients without IBD (rCDI-IBD); 2.) rCDI with IBD (rCDI+IBD); 3.) UC patients without rCDI (UC-rCDI); 4.) CD patients without rCDI (CD-rCDI).

METHODS

We performed 16S rRNA gene sequence, shotgun DNA sequence and quantitative bile acid metabolomic analyses on stools collected from 55 pairs of subjects and donors enrolled in two prospective single arm FMT clinical trials (Clinical Trials.gov ID NCT03268213, 479696, UC no rCDI ≥ 2x IND 1564 and NCT03267238, IND 16795). Fitted linear mixed models were used to examine the effects of four recipient groups, FMT status (Donor, pre-FMT, 1-week post-FMT, 3-months post-FMT) and first order Group*FMT interactions on microbial diversity and composition, bile acid metabolites and bile acid metabolizing enzyme gene abundance.

RESULTS

The pre-FMT stools collected from rCDI ± IBD recipients had reduced α-diversity compared to the healthy donor stools and was restored post-FMT. The α-diversity in the pre-FMT stools collected from UC-rCDI or CD-rCDI recipients did not differ significantly from donor stools. FMT normalized some recipient/donor ratios of genus level taxa abundance in the four groups. Fecal secondary BA levels, including some of the secondary BA epimers that exhibit in vitro immunomodulatory activities, were lower in rCDI±IBD and CD-rCDI but not UC-rCDI recipients compared to donors. FMT restored secondary BA levels. Metagenomic baiE gene and some of the eight bile salt hydrolase (BSH) phylotype abundances were significantly correlated with fecal BA levels.

CONCLUSION

Restoration of multiple secondary BA levels, including BA epimers implicated in immunoregulation, are associated with restoration of fecal baiE gene counts, suggesting that the 7-α-dehydroxylation step is rate-limiting.

Fecal microbiota transplantation for diseases: Therapeutic potential, methodology, risk management in clinical practice

BACKGROUND

More than 95 % of human diseases may be related to the disturbance of gut microbes. As a treatment method that extensively regulates the gut microbes, fecal microbiota transplantation (FMT) has proven to be an effective therapy for some diseases, becoming a topic of interest among clinicians, patients and scientists.

AIM

To review the latest clinical research results of FMT in the treatment of various diseases and the methodology and risk management in clinical application.

METHODS

Search PubMed and Web of Science for reliable research results of clinical treatment of FMT within 5-10 years, as well as application guidelines and risk management policies in different regions.

RESULTS

As a measure of allogeneic/autologous microbiota transplantation, FMT has been used to treat a variety of diseases. By reviewing the clinical studies of FMT in gastrointestinal diseases, metabolic diseases, neurological diseases and malignant tumors, the various mechanisms in the treatment of diseases are summarized. Such as regulation of receptor microbiota composition, specific metabolites, phage function and immune response. In addition, potential risk factors, donor stool screening indicators, recipient self-specificity and possible prognostic marker molecules in the course of FMT treatment were generalized.

CONCLUSIONS

The potential regulatory mechanisms, risk factors and targets of FMT in gastrointestinal diseases, metabolic diseases, malignancies and neurological diseases were reviewed and proposed. It provides a theoretical basis for the establishment of a standardized treatment system for FMT and a breakthrough in treatment technology.

Gut Microbiome in Inflammatory Bowel Disease: Role in Pathogenesis, Dietary Modulation, and Colitis-Associated Colon Cancer

The gut microbiome has increasingly been recognized as a critical and central factor in inflammatory bowel disease (IBD). Here, we review specific microorganisms that have been suggested to play a role in the pathogenesis of IBD and the current state of fecal microbial transplants as a therapeutic strategy in IBD. We discuss specific nutritional and dietary interventions in IBD and their effects on gut microbiota composition. Finally, we examine the role and mechanisms of the gut microbiome in mediating colitis-associated colon cancer.

Features of Gut Microbiome Associated With Responses to Fecal Microbiota Transplantation for Inflammatory Bowel Disease: A Systematic Review

Fecal microbiota transplantation (FMT) has been seen as a novel treatment for inflammatory bowel disease (IBD). The results on microbial alterations and their relationship to treatment efficacy are varied among studies. We performed a systematic review to explore the association between microbial features and therapy outcomes. We searched PubMed, Web of Science, Embase, and Cochrane Library databases from inception to November 2020. Studies that investigated the efficacy of FMT and baseline microbial features or dynamic alteration of the microbiome during FMT were included. The methodological quality of the included cohort studies and randomized controlled trials (RCTs) was assessed using the Newcastle-Ottawa Scale (NOS) and the Cochrane risk of bias tool, respectively. A total of 30 studies were included in the analysis. Compared to non-responders, the microbial structure of patients who responded to FMT had a higher similarity to that of their donors after FMT. Donors of responders (R-d) and non-responders (NR-d) had different microbial taxa, but the results were inconsistent. After FMT, several beneficial short-chain fatty acids- (SCFA-) producing taxa, such as Faecalibacterium, Eubacterium, Roseburia, and species belonging to them, were enriched in responders, while pathogenic bacteria (Escherichia coli and Escherichia-Shigella) belonging to the phylum Proteobacteria were decreased. Alterations of microbial functional genes and metabolites were also observed. In conclusion, the response to FMT was associated with the gut microbiota and their metabolites. The pre-FMT microbial features of recipients, the comparison of pre- and post-FMT microbiota, and the relationship between recipients and donors at baseline should be further investigated using uniform and standardized methods.

Encapsulated Fecal Microbiota Transplantation: Development, Efficacy, and Clinical Application

Fecal microbiota transplantation (FMT) has been established as a highly restorative therapeutic approach for treating recurrent Clostridioides difficile infection (rCDI). Recently, the use of capsule-based fecal microbiota transplantation (cFMT) has been shown to be a clinically effective approach to restore intestinal microbiota composition. This convenient, oral delivery provides an easy route of administration and a newfound flexibility for clinicians and patients. In this review, we discuss the development of cFMT, paying particular attention to lyophilized cFMT products. We review the available published clinical studies comparing cFMT with lower endoscopic FMT (eFMT) or placebo. We further discuss the pharmacokinetics of FMT, which should be understood in a framework of microbial ecology that considers the complex and dynamic interactions of gut microbiota with host factors and other microorganisms. Promisingly, the results of multiple trials investigating cFMT vs. eFMT in rCDI show cFMT to be as effective as eFMT at preventing rCDI. However, its efficacy in non-rCDI conditions, including obesity and metabolic syndrome, inflammatory bowel disease, HIV, and neurologic conditions, is less clear and more research is needed in these areas. Standardization of formulation, dose, and timing of administration to ensure optimal microbiota engraftment and clinical response is also a challenge to be addressed. Overall, cFMT is a practical method for fecal microbiota transplantation, with similar efficacy to eFMT in the resolution of rCDI, that holds therapeutic potential in a variety of other diseases.

A review of the therapeutic management of Crohn's disease

Crohn's disease is a chronic inflammatory, relapsing-remitting, and progressive gastrointestinal disorder with an often-negative impact on the physical, emotional, and psychological well-being. Over the past two decades, the medical compendium for the treatment of Crohn's disease has increased significantly, enabling treatment beyond symptoms. Indeed, early and timely use of effective medical therapy has been reflected by improved outcomes with reduction in surgery and ability to achieve clinical and endoscopic remission, reduce corticosteroid dependance, and prevent long-term complications in more patients. In this review, we discuss the key milestones in the medical management of Crohn's disease.

Fecal microbiota transplantation therapy in Crohn's disease: Systematic review

BACKGROUND

The gastrointestinal microbiota is the key antigenic drive in the inflammatory bowel diseases. Randomized controlled trials (RCTs) in ulcerative colitis have established fecal microbiota transplantation (FMT) as an effective therapy. We have conducted a systematic review to evaluate the efficacy of FMT in Crohn's disease.

METHODS

A systematic literature search was performed through to August 2020 (MEDLINE; Embase). Studies were included if they reported FMT administration in patients with Crohn's disease, and reported on clinical outcomes.

RESULTS

Fifteen studies published between 2014 and 2020, comprising 13 cohort studies and two RCTs, were included in the analysis. The majority of trials evaluated FMT for induction of remission, with follow-up duration varying from 4 to 52 weeks. One RCT in 21 patients, of single-dose FMT versus placebo, following steroid-induced remission, showed a higher rate of steroid-free clinical remission in the FMT group compared to the control group: 87.5% vs 44.4% at week 10 (P = 0.23). Another RCT, two-dose FMT in 31 patients, showed an overall clinical remission rate of 36% at week 8, however, with no difference in clinical or endoscopic endpoints between FMT administered by gastroscopy and colonoscopy. Considering all studies, the clinical response rates in early follow up were higher following multiple FMT than with single FMT. FMT dose did not appear to influence clinical outcomes, nor did whether FMT was fresh or frozen. FMT delivered via upper gastrointestinal route demonstrated higher early efficacy rates of 75 to 100% compared with lower delivery route rates of 30% to 58%, but on follow up beyond 8 weeks, this difference was not maintained. Whether pre-FMT antibiotic administration was beneficial was not able to be determined due to the limited number of patients receiving antibiotics and varying antibiotic regimens. No serious adverse events were reported.

CONCLUSIONS

Preliminary studies suggest that FMT may be an effective therapy in Crohn's disease. However large controlled trials are needed. No serious safety concerns have been identified.

Potential roles of gut microbiota and microbial metabolites in Parkinson's disease

Parkinson's disease (PD) is a complicated neurodegenerative disease attributed to multifactorial changes. However, its pathological mechanism remains undetermined. Accumulating evidence has revealed the emerging functions of gut microbiota and microbial metabolites, which can affect both the enteric nervous system and the central nervous system via the microbiota-gut-brain axis. Accordingly, intestinal dysbiosis might be closely associated with PD. This review explores alterations to gut microbiota, correlations with clinical manifestations of PD, and briefly probes the underlying mechanisms. Next, the highly controversial roles of microbial metabolites including short-chain fatty acids (SCFAs), H₂ and H₂S are discussed. Finally, the pros and cons of the current treatments for PD, including those targeting microbiota, are assessed. Advancements in research techniques, further studies on levels of specific strains and longitudinal prospective clinical trials are urgently needed for the identification of early diagnostic markers and the development of novel therapeutic approaches for PD.

New targets in inflammatory bowel disease therapy: 2021

PURPOSE OF REVIEW

In the rapidly progressing world of inflammatory bowel disease, this review discusses and summarizes new drug targets and results from major clinical trials in order to provide an update to physicians treating patients with inflammatory bowel diseases (IBD).

RECENT FINDINGS

Multiple new mechanisms in the treatment of IBD are being developed and many are showing promising results in both ulcerative colitis and Crohn's disease patients. In addition to efficacy, some of these treatments may provide safety benefits over existing therapies.

SUMMARY

The IBD physicians' therapeutic armamentarium is rapidly expanding and keeping abreast of these developments is required in order to provide patients with optimized individualized care.

Intestinal Microbiota in Common Chronic Inflammatory Disorders Affecting Children

The incidence and prevalence rate of chronic inflammatory disorders is on the rise in the pediatric population. Recent research indicates the crucial role of interactions between the altered intestinal microbiome and the immune system in the pathogenesis of several chronic inflammatory disorders in children, such as inflammatory bowel disease (IBD) and autoimmune diseases, such as type 1 diabetes mellitus (T1DM) and celiac disease (CeD). Here, we review recent knowledge concerning the pathogenic mechanisms underlying these disorders, and summarize the facts suggesting that the initiation and progression of IBD, T1DM, and CeD can be partially attributed to disturbances in the patterns of composition and abundance of the gut microbiota. The standard available therapies for chronic inflammatory disorders in children largely aim to treat symptoms. Although constant efforts are being made to maximize the quality of life for children in the long-term, sustained improvements are still difficult to achieve. Additional challenges are the changing physiology associated with growth and development of children, a population that is particularly susceptible to medication-related adverse effects. In this review, we explore new promising therapeutic approaches aimed at modulation of either gut microbiota or the activity of the immune system to induce a long-lasting remission of chronic inflammatory disorders. Recent preclinical studies and clinical trials have evaluated new approaches, for instance the adoptive transfer of immune cells, with genetically engineered regulatory T cells expressing antigen-specific chimeric antigen receptors. These approaches have revolutionized cancer treatments and have the potential for the protection of high-risk children from developing autoimmune diseases and effective management of inflammatory disorders. The review also focuses on the findings of studies that indicate that the responses to a variety of immunotherapies can be enhanced by strategic manipulation of gut microbiota, thus emphasizing on the importance of proper interaction between the gut microbiota and immune system for sustained health benefits and improvement of the quality of life of pediatric patients.

Probiotics, Prebiotics and Synbiotics in Inflammatory Bowel Diseases

Inflammatory bowel diseases (IBD), which include Crohn's disease (CD) and ulcerative colitis (UC), are chronic inflammatory diseases of the digestive tract with periods of remission and relapses. The etiopathogenesis of IBD is multifactorial and has not been fully understood. Hence, only symptomatic treatment of these diseases is possible. The current pharmacological treatment has variable efficacy and is associated with the risk of significant side effects. Therefore, there is a constant need to search for new types of therapies with a high safety profile. Considering that the qualitative and quantitative profile of the gastrointestinal microbiome is often different in patients with IBD than in healthy individuals, there is a need for looking for therapies aimed at restoring intestinal microbiome homeostasis. Thus, the use of strictly defined probiotics, prebiotics and synbiotics may become an alternative form of IBD therapy. There is evidence that treatment with certain probiotic strains, e.g., VSL#3 and Escherischia coli Nissle 1917, is an effective form of therapy to induce remission in patients with mild to moderate UC. So far, the effectiveness of the use of probiotics, prebiotics and synbiotics in inducing or maintaining remission in patients with CD has not been confirmed. There are also reports of possible beneficial effects of fecal microbiota transplantation (FMT) on the course of IBD, especially UC. Further, well-planned studies on a large group of patients are needed to determine the role of specific probiotic strains, prebiotics, synbiotics and FMT in the treatment of IBD in adults and in children.

Disorders of the enteric nervous system - a holistic view

The enteric nervous system (ENS) is the largest division of the peripheral nervous system and closely resembles components and functions of the central nervous system. Although the central role of the ENS in congenital enteric neuropathic disorders, including Hirschsprung disease and inflammatory and functional bowel diseases, is well acknowledged, its role in systemic diseases is less understood. Evidence of a disordered ENS has accumulated in neurodegenerative diseases ranging from amyotrophic lateral sclerosis, Alzheimer disease and multiple sclerosis to Parkinson disease as well as neurodevelopmental disorders such as autism. The ENS is a key modulator of gut barrier function and a regulator of enteric homeostasis. A 'leaky gut' represents the gateway for bacterial and toxin translocation that might initiate downstream processes. Data indicate that changes in the gut microbiome acting in concert with the individual genetic background can modify the ENS, central nervous system and the immune system, impair barrier function, and contribute to various disorders such as irritable bowel syndrome, inflammatory bowel disease or neurodegeneration. Here, we summarize the current knowledge on the role of the ENS in gastrointestinal and systemic diseases, highlighting its interaction with various key players involved in shaping the phenotypes. Finally, current flaws and pitfalls related to ENS research in addition to future perspectives are also addressed.

Urinary Microbiome: Yin and Yang of the Urinary Tract

The application of next generation sequencing techniques has allowed the characterization of the urinary tract microbiome and has led to the rejection of the pre-established concept of sterility in the urinary bladder. Not only have microbial communities in the urinary tract been implicated in the maintenance of health but alterations in their composition have also been associated with different urinary pathologies, such as urinary tract infections (UTI). Therefore, the study of the urinary microbiome in healthy individuals, as well as its involvement in disease through the proliferation of opportunistic pathogens, could open a potential field of study, leading to new insights into prevention, diagnosis and treatment strategies for urinary pathologies. In this review we present an overview of the current state of knowledge about the urinary microbiome in health and disease, as well as its involvement in the development of new therapeutic strategies.

Faecal microbiota transplantation: what's beyond Clostridium difficile infection?

Over the last decade, major advancements have been made in our understanding of both the beneficial and detrimental role that microorganisms play in our innate functioning. Research into the intestinal microbiota has moved from the laboratory into our medical clinics and is being put forth as an effective therapy for a range of medical conditions, not only limited to the gastrointestinal system. The clearest example of this progression has been in the treatment of Clostridium difficile infection; however, faecal microbiota transplantation has also been shown to have a positive effect in the treatment of inflammatory disorders, such as ulcerative colitis. In this review article, we will appraise the existing literature examining the role the intestinal microbiota plays in the pathogenesis of disease and the therapeutic utility of faecal microbiota transplantation in restoring homeostasis. In many cases, these studies are in a preclinical setting, are small in scale and often are not placebo-controlled; however, the results from these studies report interesting associations between intestinal dysbiosis and disease development, as well as the beneficial effects of faecal microbiota transplantation in reversing this process.

Fecal microbiota transplantation for Crohn's disease: a systematic review and meta-analysis

BACKGROUND

Crohn's disease (CD) is a chronic idiopathic inflammatory intestinal disorder associated with fecal dysbiosis. Fecal microbiota transplantation (FMT) is an emerging treatment approach for CD. But its efficacy and safety remain controversial. We performed a systematic review and meta-analysis to evaluate the efficacy and safety of FMT in CD patients.

METHODS

Electronic databases were searched for studies that reported efficacy and/or safety of FMT for CD. Clinical remission was established as the primary outcome. Secondary outcome was clinical response. Odds ratios with 95% confidence intervals (CIs) were reported.

RESULTS

In all, 12 trials were included in our study. Pooled analysis showed that 0.62 (95% CI 0.48, 0.81) of CD patients achieved clinical remission and 0.79 (95% CI 0.71, 0.89) of CD patients achieved clinical response post-FMT. Sub-analyses suggested the rate of clinical remission with fresh stool FMT was higher than with frozen stool FMT (73% vs 43%; p < 0.05). Most adverse events were minor and self-resolving and no major FMT-related adverse event has been reported so far.

CONCLUSIONS

The evidence showed that FMT is an effective and safe therapy for CD. FMT may be successful because it increases the overall diversity of enteric microbiome. Additional randomized controlled studies are needed.

Advances in the understanding of the intestinal micro-environment and inflammatory bowel disease

The human gastrointestinal tract accommodates an entire micro-environment for divergent physiologic processes, the dysbiosis of this micro-ecology has a strong inter-action with the pathogenesis of inflammatory bowel disease (IBD). In the past few years, with the advances in the understanding of microbiome, its metabolites and further application of next generation sequencing, analysis of dynamic alteration of gut micro-environment was realized, which provides numerous information beyond simple microbiota structure or metabolites differences under chronic colitis status. The subsequent intervention strategies targeting the modulation of intestinal micro-environment have been explored as a potential therapy. In this review, we will summarize the recent knowledge about multi-dimensional dysbiosis, the inter-action between fungus and bacteria under inflamed mucosa, and the clinical application of probiotics and fecal microbiota transplantation as a promising therapeutic approach in IBD.

Clinical response and changes in the fecal microbiota and metabolite levels after fecal microbiota transplantation in patients with inflammatory bowel disease and recurrent Clostridioides difficile infection

OBJECTIVES

We determined the efficacy of fecal microbiota transplantation (FMT) and subsequent changes in fecal microbiota and short-chain fatty acid (SCFA) levels in patients with ulcerative colitis (UC), Crohn's disease (CD), and recurrent Clostridioides difficile infection (rCDI).

METHODS

A filtered solution of Japanese donor feces was endoscopically administered. The efficacy of FMT was evaluated after 8 weeks using the Mayo score, Crohn's Disease Activity Index (CDAI), and the absence of diarrhea with stool toxin negativity in patients with active UC, CD, and rCDI, respectively. For fecal microbiota analysis, the 16S ribosomal RNA gene was sequenced, and fecal SCFA levels were measured.

RESULTS

Clinical response was achieved in 5/20 (25%), 3/4 (75%), and 4/4 (100%) patients with UC, CD, and rCDI, respectively. Clinical remission was achieved in 4/20 (20%) and 1/4 (25%) patients with UC and CD, respectively. Linear discriminant analysis illustrated that UC responders had lower counts of Clostridium cluster XIVa before FMT and higher counts after FMT. Higher Fusicatenibacter saccharivorans counts in donors were significantly correlated with 8-week clinical remission. Patients with CD exhibited lower Blautia, Dorea, and Eubacterium counts before FMT and higher Collinsella, Dorea, and Eubacterium counts after FMT, accompanied by functional profiles predictive of SCFA fermentation and elevated fecal butyrate concentrations. Patients with rCDI displayed significantly lower abundances of Clostridium clusters IV and XIVa before FMT and higher abundances after FMT accompanied by elevated fecal propionate concentrations.

CONCLUSIONS

FMT exhibited various efficacy against UC, CD, and rCDI by altering the gut microbiota and SCFA production.

Microbiota Transplant in the Treatment of Obesity and Diabetes: Current and Future Perspectives

A wealth of evidence has revealed the critical role of the gut microbiota in health and disease. Many chronic diseases have been associated with gut microbiota imbalance in its composition, diversity and functional capacity. Several types of interventions have been shown to correct microbiota imbalance and restore the beneficial metabolic outcomes of a normal microbiota. Among them, fecal microbiota transplantation (FMT) is an emergent, promising technology employed to improve clinical outcomes of various pathological conditions through modifications in the gut microbiota composition. FMT has been used successfully as a treatment option in recurrent Clostridium difficile infection, a condition characterized by severe gut microbiota dysbiosis. However, the potential usage of FMT in other microbiota-associated conditions different from C. difficile such as metabolic syndrome or obesity that are also marked by gut dysbiosis is still under investigation. Furthermore, the contribution of the gut microbiota as a cause or consequence in metabolic disease is still largely debated. This review provides critical information on the methodological approaches of FMT and its technological innovation in clinical applications. This review sheds light on the current findings and gaps in our understanding of how FMT can be used as a future biotherapeutic to restore microbial homeostasis in amelioration of obesity and diabetes.

Fecal microbiota transplantation in inflammatory bowel disease patients: A systematic review and meta-analysis

Objectives

Current evidence on fecal microbiota transplantation for inflammatory bowel disease is inconclusive. We conducted a systematic review to gather evidence on the efficacy and safety of fecal microbiota transplantation for inflammatory bowel disease.

Methods

Systematic searches were conducted in PubMed, Scopus, and Web of Science. Clinical remission was considered as the primary endpoint. Pairwise meta-analyses were performed for the randomized controlled studies (Mantel Haenszel, random effects model). Proportion meta-analyses, accounting for weighted pooled rates reported in the interventional studies, were conducted using the mixed effects model. Subgroup analyses considering the type of stool, donor type, and disease subtype were also performed. Cumulative meta-analyses to assess further needs of evidence were conducted.

Results

Sixty studies were included, from which 36 could be synthesized in the quantitative analyses. Pairwise meta-analyses of six controlled trials showed significant differences in favor of fecal microbiota transplantation compared with placebo (clinical remission: RR 1.70 [95% CI 1.12, 2.56]; clinical response: RR 1.68 [95% CI 1.04, 2.72]). An overall clinical remission of 37%, overall clinical response of 54%, and a prevalence of 29% of adverse events were found for the interventional studies. Frozen fecal material and universal donors were related to better efficacy outcomes. In addition, Crohn’s disease patients seemed to benefit more from the procedure.

Conclusions

The comparative analyses demonstrated that frozen fecal material from universal donors may be related to a higher rate of clinical remission, especially for Crohn’s disease.

Fecal Microbiota Transplantation for the Treatment of Inflammatory Bowel Disease: An Update

Fecal microbiota transplantation (FMT) has successfully been applied for the treatment of recurrent Clostridioides difficile infection (CDI), which has led to studies on its application to other gastrointestinal diseases and extraintestinal diseases associated with gut microbiota dysbiosis. Recently, the results of FMT for patients with inflammatory bowel disease (IBD) have been encouraging. However, studies have not fully clarified the clinical application of this emerging therapy. Here, we aimed to review the current knowledge in this fast-growing field and characterize the effectiveness, safety and mechanisms of FMT for the treatment of IBD patients.

Fecal microbial transplant for inflammatory bowel disease

PURPOSE OF REVIEW

The purpose of this brief review is to investigate the current utility of fecal microbial transplantation (FMT) to ameliorate dysbiosis contributing to inflammatory bowel disease pathogenesis.

RECENT FINDINGS

Increasing data from randomized, controlled trials support a role for multiple FMT administrations in the induction of remission and even as a maintenance therapy in mild-to-moderate Ulcerative Colitis. Small series and one small randomized controlled trial among patients with Crohn's Disease and with pouchitis continue to produce conflicting clinical results and microbial profile data on the host and donor levels. It is not clear whether patients with Crohn's disease are more susceptible to disease flare after FMT. Novel FMT delivery systems, including oral, and early-intensity colonoscopic devices, are under investigation.

SUMMARY

The allure of minimizing the risks and cost of long-term immunosuppression via modulation of patient microbiota remains enticing, and the most recent randomized controlled data in ulcerative colitis reveals acceptable clinical remission rates. However, prior to wide adoption of FMT within the inflammatory bowel disease treatment armamentarium, large clinical trials identifying biomarkers of treatment success, ensuring safety across all indications, and cultivating optimized donor and host selection are needed.

Regulation of the intestinal microbiota: An emerging therapeutic strategy for inflammatory bowel disease

The rapid development of metagenomics, metabolomics, and metatranscriptomics provides novel insights into the intestinal microbiota factors linked to inflammatory bowel disease (IBD). Multiple microorganisms play a role in intestinal health; these include bacteria, fungi, and viruses that exist in a dynamic balance to maintain mucosal homeostasis. Perturbations in the intestinal microbiota disrupt mucosal homeostasis and are closely related to IBD in humans and colitis in mice. Therefore, preventing or correcting the imbalance of microbiota may serve as a novel prevention or treatment strategy for IBD. We review the most recent evidence for direct or indirect interventions targeting intestinal microbiota for treatment of IBD in order to overcome the current limitations of IBD therapies and shed light on personalized treatment options.

Efficacy of faecal microbiota transplantation in Crohn's disease: a new target treatment?

The efficacy of faecal microbiota transplantation (FMT) in Crohn's disease (CD) remains unclear due to lack of data. This study aimed to assess the value of FMT in treating CD-related clinical targets. The use of FMT for CD as a registered trial (NCT01793831) was performed between October 2012 and December 2017. Seven therapeutic targets included abdominal pain, diarrhoea, hematochezia, fever, steroid-dependence, enterocutaneous fistula and active perianal fistula. Each target was recorded as 1 (yes) or 0 (no) during the long-term follow-up for each patient. The primary outcome was the rate of improvement in each therapeutic target. Overall, 174 patients completed the follow-up. The median follow-up duration was 43 (interquartile range, 28-59) months. The median score of the total targets was 2 (range, 1-4) before FMT, and it decreased significantly at 1, 3, 6, 12, 24 and 36 months after FMT (P < 0.001 respectively). At 1 month after FMT, 72.7% (101/139), 61.6% (90/146), 76% (19/25) and 70.6% (12/17) of patients achieved improvement in abdominal pain, diarrhoea, hematochezia and fever respectively. Furthermore, 50% (10/20) of steroid-dependent patients achieved steroid-free remission after FMT. The present findings indicate that it is important to understand the efficacy of FMT in CD as a targeted therapy, especially for abdominal pain, hematochezia, fever and diarrhoea.

Characteristics of Fecal Microbiota Transplantation Use in Inflammatory Bowel Disease Cohort

BACKGROUND

There is a growing interest in the role of gut bacteria in a number of diseases and an emerging hypothesis that inflammatory bowel disease (IBD) is triggered by microbial dysbiosis in genetically susceptible individuals. Currently, fecal microbiota transplantation (FMT) is utilized for the treatment of Clostridium difficile colitis. Data on the efficacy of FMT for IBD are mixed, but patients are interested in its use for the treatment of IBD. We sought to describe the use of FMT (self or medical professional administered) in individuals with IBD using IBD Partners, an Internet-based cohort.

METHODS

Patients enrolled in the IBD Partners cohort were offered the opportunity to complete an optional survey on the use of FMT between January 2017 to September 2018 (n = 5430). A cross-sectional analysis was performed within patients who completed the survey and did not have a pouch or ostomy. Patients' demographic characteristics, disease activity and phenotype, mode of FMT delivery, and patient-reported efficacy were compared.

RESULTS

Among 3274 eligible patients, 51 (1.6%) responded that they had an FMT in the past. Of patients undergoing FMT, 22 patients had the FMT for C. difficile while 29 reported that the FMT was for another indication. Most patients receiving FMT for an indication other than C. difficile had ulcerative colitis/indeterminate colitis (25, 86.2%). Colonoscopy (68.2%) and nasogastric tube (18.2%) were the most common routes of administration for patients receiving FMT for C. difficile colitis. Self-administration (72.4%) and enemas (17.2%) were the most common routes of administration in patients receiving FMT for an alternate indication. Patients reporting FMT for an indication other than C. difficile were less likely to have a physician directing their FMT treatment (20.6%) as compared to patients receiving FMT for C. difficile (86.3%). Patient-reported efficacy was lower for FMT given for a non-C. difficile indication.

CONCLUSIONS

Patients undergoing FMT for an indication other than C. difficile infection were more likely to have ulcerative colitis, self-administer FMT, and were less likely to be receiving FMT under the guidance of a medical professional. FMT was not as effective for symptoms when given for a non-C. difficile indication. Patients should be counseled on potential harms and lack of proven benefit associated with FMT for IBD indications to try to discourage self-administered FMT without proper medical oversite.

Faecal microbiota transplantation: Application in treatment of some digestive diseases and safety concerns

Intestinal microbiota is an essential part of the body, and it closely relates to normal functioning of the host as well as the onset of a variety of diseases. Faecal microbiota transplantation (FMT) is the major method to modify the intestinal dysbiosis. Currently, it has been approved for treatment of refractory/recurrent Clostridium difficile infection by the US Food and Drug Administration. Clinical trials also suggested that FMT may have effects on a variety of systemic diseases. In this paper, we briefly reviewed the current status of FMT application in most studied digestive diseases such as inflammatory bowel diseases, hepatic encephalopathy, irritable bowel syndrome, and cancer. The adverse effects and complications disclosed in these studies are analyzed in the context of current administrative rules, and safety concerns are discussed.

Recent advances in modulating the microbiome

We are in the midst of “the microbiome revolution”—not a day goes by without some new revelation on the potential role of the gut microbiome in some disease or disorder. From an ever-increasing recognition of the many roles of the gut microbiome in health and disease comes the expectation that its modulation could treat or prevent these very same diseases. A variety of interventions could, at least in theory, be employed to alter the composition or functional capacity of the microbiome, ranging from diet to fecal microbiota transplantation (FMT). For some, such as antibiotics, prebiotics, and probiotics, an extensive, albeit far from consistent, literature already exists; for others, such as other dietary supplements and FMT, high-quality clinical studies are still relatively few in number. Not surprisingly, researchers have turned to the microbiome itself as a source for new entities that could be used therapeutically to manipulate the microbiome; for example, some probiotic strains currently in use were sourced from the gastrointestinal tract of healthy humans. From all of the extant studies of interventions targeted at the gut microbiome, a number of important themes have emerged. First, with relatively few exceptions, we are still a long way from a precise definition of the role of the gut microbiome in many of the diseases where a disturbed microbiome has been described—association does not prove causation. Second, while animal models can provide fascinating insights into microbiota–host interactions, they rarely recapitulate the complete human phenotype. Third, studies of several interventions have been difficult to interpret because of variations in study population, test product, and outcome measures, not to mention limitations in study design. The goal of microbiome modulation is a laudable one, but we need to define our targets, refine our interventions, and agree on outcomes.

Fecal microbiota transplantation results in bacterial strain displacement in patients with inflammatory bowel diseases

Fecal microbiota transplantation (FMT), which is thought to have the potential to correct dysbiosis of gut microbiota, has been used to treat inflammatory bowel disease (IBD) for almost a decade. Here, we report an interventional prospective cohort study performed to elucidate the extent of and processes underlying microbiota engraftment in IBD patients after FMT treatment. The cohort included two categories of patients: (a) patients with moderate to severe Crohn’s disease (CD) (Harvey–Bradshaw Index ≥ 7, n = 11) and (b) patients with ulcerative colitis (UC) (Montreal classification S2 and S3, n = 4). All patients were treated with a single FMT (via mid‐gut, from healthy donors), and follow‐up visits were performed at baseline, 3 days, 1 week, and 1 month after FMT (missing time points included). At each follow‐up time point, fecal samples and clinical metadata were collected. For comparative analysis, 10 fecal samples from 10 healthy donors were included to represent the diversity level of normal gut microbiota. Additionally, the metagenomic data of 25 fecal samples from five individuals with metabolic syndrome who underwent autologous FMT treatment were downloaded from a previous published paper to represent fluctuations in microbiota induced during FMT. All fecal samples underwent shotgun metagenomic sequencing. We found that 3 days after FMT, 11 out of 15 recipients were in remission (three out of four UC recipients; 8 out of 11 CD recipients). Generally, bacterial colonization was observed to be lower in CD recipients than in UC recipients at both species and strain levels. Furthermore, across species, different strains displayed disease‐specific displacement advantages under two‐disease status. Finally, most post‐FMT species (> 80%) could be properly predicted (area under the curve > 85%) using a random forest classification model, with the gut microbiota composition and clinical parameters of pre‐FMT recipients acting as factors that contribute to prediction accuracy.

Gut microbiota, dysbiosis and colon lavage

Gut microbial dysbiosis is considered an alteration of diversity and abundance of intestinal microbes, which contributes to the onset of many disorders. Several factors cause dysbiosis, depending on life-style (nutrition, stress, environment, smoking, physical activity) or particular diseases (inflammatory, autoimmune, chronic diseases). Drugs (i.e. antibiotics, anticancer drugs), as well as medical and surgical procedures, can often cause dysbiosis. Mechanical bowel preparations (MBP) and the so called "bowel cleansing" have an immediate impact on intestinal microbial composition. Whether these "acute" changes may lead to any clinical consequences is still unknown. It is tempting to speculate that such dysbiosis fostering events, at least in patients already presenting abdominal complaints, such as irritable bowel syndrome (IBS), or inflammatory bowel disease (IBD) patients, may drive additional or more severe symptoms. Recently, the possibility of using probiotic supplementation has been addressed in the literature, with the purpose to counteract intestinal dysfunctional changes observed in relation to a dysbiotic state. Whereas probiotics are recognized to be effective and safe in restoring gut microbiota dysbiosis, preliminary evidence suggest that this approach may prove helpful even in case of transient dysbiotic states related to colonoscopy bowel preparation.