Fecal Microbiota Transplantation as a Novel Therapy for Ulcerative Colitis: A Systematic Review and Meta-Analysis

Microbiota Therapy in Inflammatory Bowel Disease

Background

In both Crohn's disease (CD) and ulcerative colitis (UC), the two major forms of inflammatory bowel disease (IBD) the immune reaction is - at least partially - directed against components of the luminal microbiota of the gut. These immune responses as well as other factors contribute to a phenomenon frequently described as "dysbiosis" meaning an alteration of the composition of the colonic microbiota. To improve the dysbiosis and to restore the normal composition of the colonic microbiota, fecal microbiota transplantation (FMT) has been tested as a therapeutic option to induce and maintain remission in IBD patients.

Summary

This review will first discuss changes in the composition of the intestinal microbiota found in IBD patients and second the therapeutic potential of microbiological interventions for the treatment of these patients. FMT has been studied in several clinical trials in both, CD and UC. Reported results and subsequent meta-analyses indicate that FMT may be effective to induce remission in UC. However, the optimal route of FMT, the necessary number of administrations and the question whether life bacteria of freshly prepared stool is more effective than frozen are still unclear. Concepts associated with an optimization of FMT such as the "super donor concept" or the "consortia-approach" will be discussed to illustrate open questions and difficulties associated with microbiota therapy in IBD.

Key Messages

The microbiota composition in IBD patients shows significant alterations compared to healthy individuals termed as "dysbiosis". FMT and other therapeutic approaches to modify the microbiota composition have been studied in clinical trials in recent years. Efficacy has been shown in UC; however, many questions with respect to the optimization of microbiota therapy remain to be answered.

Role of Fecal Microbiota Transplantation in Managing Clostridium Difficile Infection and Inflammatory Bowel Disease: A Narrative Review

Fecal microbiota transplantation (FMT) has been emerging as an alternate treatment modality in the management of patients with dysbiosis by restoring abnormal gut microbiota composition through the transplantation of normal fecal microbiota from healthy donors. This technique has lately gained a lot of attention in the treatment of recurrent or refractory Clostridium difficile infection (CDI) owing to its high success rates combined with its favorable safety profile. FMT has also been attracting the interest of clinicians as a new treatment option for inflammatory bowel diseases (IBD). Here, we reviewed most of the recent advancements in the use of FMT for CDI as well as its use in the treatment of IBD.

Fecal transplantation for treatment of inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) is a chronic, relapsing disease of the gastrointestinal (GI) tract that is thought to be associated with a complex interplay between the immune system, the GI tract lining, the environment, and the gut microbiome, leading to an abnormal inflammatory response in genetically susceptible individuals. An altered composition of the gut's native microbiota, known as dysbiosis, may have a major role in the pathogenesis of ulcerative colitis (UC) and Crohn disease (CD), two subtypes of IBD. There is growing interest in the correction of this underlying dysbiosis using fecal microbiota transplantation (FMT).

OBJECTIVES

To evaluate the benefits and safety profile of FMT for treatment of IBD in adults and children versus autologous FMT, placebo, standard medication, or no intervention.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, two clinical trial registries, and the reference sections of published trials through 22 December 2022.

SELECTION CRITERIA

We included randomized controlled trials that studied adults and children with UC or CD. Eligible intervention arms used FMT, defined as the delivery of healthy donor stool containing gut microbiota to a recipient's GI tract, to treat UC or CD.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened studies for inclusion. Our primary outcomes were: 1. induction of clinical remission, 2. maintenance of clinical remission, and 3. serious adverse events. Our secondary outcomes were: 4. any adverse events, 5. endoscopic remission, 6. quality of life, 7. clinical response, 8. endoscopic response, 9. withdrawals, 10. inflammatory markers, and 11. microbiome outcomes. We used the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

We included 12 studies with 550 participants. Three studies were conducted in Australia; two in Canada; and one in each of the following: China, the Czech Republic, France, India, the Netherlands, and the USA. One study was conducted in both Israel and Italy. FMT was administered in the form of capsules or suspensions and delivered by mouth, nasoduodenal tube, enema, or colonoscopy. One study delivered FMT by both oral capsules and colonoscopy. Six studies were at overall low risk of bias, while the others had either unclear or high risk of bias. Ten studies with 468 participants, of which nine studies focused on adults and one focused on children, reported induction of clinical remission in people with UC at longest follow-up (range 6 to 12 weeks) and showed that FMT may increase rates of induction of clinical remission in UC compared to control (risk ratio (RR) 1.79, 95% confidence interval (CI) 1.13 to 2.84; low-certainty evidence). Five studies showed that FMT may increase rates of induction of endoscopic remission in UC at longest follow-up (range 8 to 12 weeks); however, the CIs around the summary estimate were wide and included a possible null effect (RR 1.45, 95% CI 0.64 to 3.29; low-certainty evidence). Nine studies with 417 participants showed that FMT may result in little to no difference in rates of any adverse events (RR 0.99, 95% CI 0.85 to 1.16; low-certainty evidence). The evidence was very uncertain about the risk of serious adverse events (RR 1.77, 95% CI 0.88 to 3.55; very low-certainty evidence) and improvement in quality of life (mean difference (MD) 15.34, 95% CI -3.84 to 34.52; very low-certainty evidence) when FMT was used to induce remission in UC. Two studies, of which one also contributed data for induction of remission in active UC, assessed maintenance of remission in people with controlled UC at longest follow-up (range 48 to 56 weeks). The evidence was very uncertain about the use of FMT for maintenance of clinical remission (RR 2.97, 95% CI 0.26 to 34.42; very low-certainty evidence) and endoscopic remission (RR 3.28, 95% CI 0.73 to 14.74; very low-certainty evidence). The evidence was also very uncertain about the risk of serious adverse events, risk of any adverse events, and improvement in quality of life when FMT was used to maintain remission in UC. None of the included studies assessed use of FMT for induction of remission in people with CD. One study with 21 participants reported data on FMT for maintenance of remission in people with CD. The evidence was very uncertain about the use of FMT for maintenance of clinical remission in CD at 24 weeks (RR 1.21, 95% CI 0.36 to 4.14; very low-certainty evidence). The evidence was also very uncertain about the risk of serious or any adverse events when FMT was used to maintain remission in CD. None of the studies reported data on use of FMT for maintenance of endoscopic remission or improvement in quality of life in people with CD.

AUTHORS' CONCLUSIONS

FMT may increase the proportion of people with active UC who achieve clinical and endoscopic remission. The evidence was very uncertain about whether use of FMT in people with active UC impacted the risk of serious adverse events or improvement in quality of life. The evidence was also very uncertain about the use of FMT for maintenance of remission in people with UC, as well as induction and maintenance of remission in people with CD, and no conclusive statements could be made in this regard. Further studies are needed to address the beneficial effects and safety profile of FMT in adults and children with active UC and CD, as well as its potential to promote longer-term maintenance of remission in UC and CD.

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.

Targeted suppression of human IBD-associated gut microbiota commensals by phage consortia for treatment of intestinal inflammation

Human gut commensals are increasingly suggested to impact non-communicable diseases, such as inflammatory bowel diseases (IBD), yet their targeted suppression remains a daunting unmet challenge. In four geographically distinct IBD cohorts (n = 537), we identify a clade of Klebsiella pneumoniae (Kp) strains, featuring a unique antibiotics resistance and mobilome signature, to be strongly associated with disease exacerbation and severity. Transfer of clinical IBD-associated Kp strains into colitis-prone, germ-free, and colonized mice enhances intestinal inflammation. Stepwise generation of a lytic five-phage combination, targeting sensitive and resistant IBD-associated Kp clade members through distinct mechanisms, enables effective Kp suppression in colitis-prone mice, driving an attenuated inflammation and disease severity. Proof-of-concept assessment of Kp-targeting phages in an artificial human gut and in healthy volunteers demonstrates gastric acid-dependent phage resilience, safety, and viability in the lower gut. Collectively, we demonstrate the feasibility of orally administered combination phage therapy in avoiding resistance, while effectively inhibiting non-communicable disease-contributing pathobionts.

Donor fecal microbiota transplantation ameliorates intestinal graft-versus-host disease in allogeneic hematopoietic cell transplant recipients

Disruption of the intestinal microbiota occurs frequently in allogeneic hematopoietic cell transplantation (allo-HCT) recipients and predisposes them to development of graft-versus-host disease (GvHD). In a prospective, single-center, single-arm study, we investigated the effect of donor fecal microbiota transplantation (FMT) on symptoms of steroid-refractory or steroid-dependent, acute or late-onset acute intestinal GvHD in 15 individuals who had undergone allo-HCT. Study participants received a fecal suspension from an unrelated healthy donor via nasoduodenal infusion. Donor FMT was well tolerated, and infection-related adverse events did not seem to be related to the FMT procedure. In 10 of 15 study participants, a complete clinical response was observed within 1 month after FMT, without additional interventions to alleviate GvHD symptoms. This response was accompanied by an increase in gut microbial α-diversity, a partial engraftment of donor bacterial species, and increased abundance of butyrate-producing bacteria, including Clostridiales and Blautia species. In 6 of the 10 responding donor FMT recipients, immunosuppressant drug therapy was successfully tapered. Durable remission of steroid-refractory or steroid-dependent GvHD after donor FMT was associated with improved survival at 24 weeks after donor FMT. This study highlights the potential of donor FMT as a treatment for steroid-refractory or steroid-dependent GvHD, but larger clinical trials are needed to confirm the safety and efficacy of this procedure.

The role of the gut microbiota in the treatment of inflammatory bowel diseases

The human intestinal microbiota coevolves with its host through a symbiotic relationship and exerts great influence on substantial functions including aspects of physiology, metabolism, nutrition and regulation of immune responses leading to physiological homeostasis. Over the last years, several studies have been conducted toward the assessment of the host-gut microbiota interaction, aiming to elucidate the mechanisms underlying the pathogenesis of several diseases. A defect on the microbiota-host crosstalk and the concomitant dysregulation of immune responses combined with genetic and environmental factors have been implicated in the pathogenesis of inflammatory bowel diseases (IBD). To this end, novel therapeutic options based on the gut microbiota modulation have been an area of extensive research interest. In this review we present the recent findings on the association of dysbiosis with IBD pathogenesis, we focus on the role of gut microbiota on the treatment of IBD and discuss the novel and currently available therapeutic strategies in manipulating the composition and function of gut microbiota in IBD patients. Applicable and emerging microbiota treatment modalities, such as the use of antibiotics, prebiotics, probiotics, postbiotics, synbiotics and fecal microbiota transplantation (FMT) constitute promising therapeutic options. However, the therapeutic potential of the aforementioned approaches is a topic of investigation and further studies are needed to elucidate their position in the present treatment algorithms of IBD.

Limonin ameliorates ulcerative colitis by regulating STAT3/miR-214 signaling pathway

Ulcerative colitis (UC) is a major inflammatory bowel disease (IBD) which has become a global public health problem. Limonin is a triterpenoid extracted from citrus which possesses the capacities to against inflammations and cell apoptosis. However, the efficacy and the underlying mechanisms of limonin in the treatment of UC remain unclear. In this study, we first investigated the therapeutic effects of limonin on dextran sodiumsulfate (DSS)-induced UC in vivo by examining the changes of disease activity index (DAI), the colon length, the colon histology, and cyto/chemokine levels. We found that limonin markedly reduced DAI, intestinal damages, and the levels of pro-inflammatory cytokines, such as TNF-α and IL-6. In vitro, limonin significantly repressed the productions of pro-inflammatory cytokines in cultured normal colonic epithelial cells. Mechanistically, we demonstrated that limonin improved the prognosis of UC mainly through downregulating p-STAT3/miR-214 levels. Collectively, our results suggested that limonin was a novel therapeutic agent and it was expected to be translated into the clinic to improve the prognosis of UC.

Fecal transplantation for treatment of inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) is a chronic, relapsing disease of the gastrointestinal tract that is thought to be associated with a complex interplay between microbes and the immune system, leading to an abnormal inflammatory response in genetically susceptible individuals. Dysbiosis, characterized by the alteration of the composition of the resident commensal bacteria in a host compared to healthy individuals, is thought to play a major role in the pathogenesis of ulcerative colitis (UC) and Crohn's disease (CD), two subtypes of IBD. There is growing interest to correct the underlying dysbiosis through the use of fecal microbiota transplantation (FMT) for the treatment of IBD.

OBJECTIVES

The objective of this systematic review was to assess the efficacy and safety of FMT for the treatment of IBD.

SEARCH METHODS

We searched the MEDLINE, Embase, Cochrane Library, and Cochrane IBD Group Specialized Register databases from inception to 19 March 2018. We also searched ClinicalTrials.gov, ISRCTN metaRegister of Controlled Trials, and the Conference Proceedings Citation Index.

SELECTION CRITERIA

Only randomized trials or non-randomized studies with a control arm were considered for inclusion. Adults or pediatric participants with UC or CD were eligible for inclusion. Eligible interventions were FMT defined as the administration of fecal material containing distal gut microbiota from a healthy donor to the gastrointestinal tract of a someone with UC or CD. The comparison group included participants who did not receive FMT and were given placebo, autologous FMT, or no intervention.

DATA COLLECTION AND ANALYSIS

Two authors independently screened the titles and extracted data from the included studies. We used the Cochrane risk of bias tool to assess study bias. The primary outcomes were induction of clinical remission, clinical relapse, and serious adverse events. Secondary outcomes included clinical response, endoscopic remission and endoscopic response, quality of life scores, laboratory measures of inflammation, withdrawals, and microbiome outcomes. We calculated the risk ratio (RR) and corresponding 95% confidence interval (95% CI) for dichotomous outcomes and the mean difference and 95% CI for continuous outcomes. Random-effects meta-analysis models were used to synthesize effect sizes across trials. The overall certainty of the evidence supporting the primary and selected secondary outcomes was rated using the GRADE criteria.

MAIN RESULTS

Four studies with a total of 277 participants were included. These studies assessed the efficacy of FMT for treatment of UC in adults; no eligible trials were found for the treatment of CD. Most participants had mild to moderate UC. Two studies were conducted in Australia, one study was conducted in Canada, and another in the Netherlands. Three of the included studies administered FMT via the rectal route and one study administered FMT via the nasoduodenal route. Three studies were rated as low risk of bias. One study (abstract publication) was rated as unclear risk of bias. Combined results from four studies (277 participants) suggest that FMT increases rates of clinical remission by two-fold in patients with UC compared to controls. At 8 weeks, 37% (52/140) of FMT participants achieved remission compared to 18% (24/137) of control participants (RR 2.03, 95 % CI, 1.07 to 3.86; I² = 50%; low certainty evidence). One study reported data on relapse at 12 weeks among participants who achieved remission. None of the FMT participants (0/7) relapsed at 12 weeks compared to 20% of control participants (RR 0.28, 95% CI 0.02 to 4.98, 17 participants, very low certainty evidence). It is unclear whether there is a difference in serious adverse event rates between the intervention and control groups. Seven per cent (10/140) of FMT participants had a serious adverse event compared to 5% (7/137) of control participants (RR 1.40, 95% CI 0.55 to 3.58; 4 studies; I² = 0%; low certainty evidence). Serious adverse events included worsening of UC necessitating intravenous steroids or surgery; infection such as Clostridium difficile and cytomegalovirus, small bowel perforation and pneumonia. Adverse events were reported by two studies and the pooled data did not show any difference between the study groups. Seventy-eight per cent (50/64) of FMT participants had an adverse event compared to 75% (49/65) of control participants (RR 1.03, 95% CI 0.81 to 1.31; I² = 31%; moderate certainty evidence). Common adverse events included abdominal pain, nausea, flatulence, bloating, upper respiratory tract infection, headaches, dizziness, and fever. Four studies reported on clinical response at 8 weeks. Forty-nine per cent (68/140) of FMT participants had a clinical response compared to 28% (38/137) of control participants (RR 1.70, 95% CI 0.98 to 2.95, I² = 50%, low certainty evidence). Endoscopic remission at 8 weeks was reported by three studies and the combined results favored FMT over the control group. Thirty per cent (35/117) of FMT participants achieved endoscopic remission compared to 10% (11/112) of control participants (RR 2.96, 95 % CI 1.60 to 5.48, I² = 0%; low certainty evidence).

AUTHORS' CONCLUSIONS

Fecal microbiota transplantation may increase the proportion of participants achieving clinical remission in UC. However, the number of identified studies was small and the quality of evidence was low. There is uncertainty about the rate of serious adverse events. As a result, no solid conclusions can be drawn at this time. Additional high-quality studies are needed to further define the optimal parameters of FMT in terms of route, frequency, volume, preparation, type of donor and the type and disease severity. No studies assessed efficacy of FMT for induction of remission in CD or in pediatric participants. In addition, no studies assessed long-term maintenance of remission in UC or CD. Future studies are needed to address the therapeutic benefit of FMT in CD and the long-term FMT-mediated maintenance of remission in UC or CD.

From the intestinal flora to the microbiome

In this article, the history of the microbiota is reviewed and the related concepts of the microbiota, microbiome, metagenome, pathobiont, dysbiosis, holobiont, phylotype and enterotype are defined. The most precise and current knowledge about the microbiota is presented and the metabolic, nutritional and immunomodulatory functions are reviewed. Some gastrointestinal diseases whose pathogenesis is associated with the intestinal microbiota, including inflammatory bowel disease, irritable bowel syndrome and celiac disease, among others, are briefly discussed. Finally, some prominent and promising data with regard to the fecal microbiota transplantation in certain digestive illness are discussed.

Protocol for Fecal Microbiota Transplantation in Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis

Background

Fecal microbiota transplantation (FMT) is an emerging treatment approach for inflammatory bowel disease (IBD). The donor selection, the separation of fecal bacteria, the frequency of FMT, the way of infusion, the long-term safety, and efficacy are still uncertain.

Aim

To further study the efficacy and safety and protocol of FMT for IBD.

Methods

A systematic review and meta-analysis were conducted until February, 2018. Clinical remission was established as the primary outcome.

Results

A total of 596 paediatric and adult IBD patients were enrolled, and 459 patients received FMT therapy. 28.8% (132/459) patients achieved clinical remission during follow-up. 53% (241/459) patients achieved clinical response. The pooled estimated clinical remission for ulcerative colitis (UC) was 21% (95% CI: 8%-37%) and 30% (95% CI: 11%-52%) for Crohn's disease (CD), both with a risk of heterogeneity; 10% (95% CI: 0%-43%) for paediatric UC; 26% (95% CI: 10%-48%) for adult UC; 45% for paediatric CD (95% CI: 24%-66%); 22% (95% CI: 3%-52%) for adult CD. Meta-analysis of cohort studies showed that moderate-severe IBD patients could achieve more significant remission from FMT than mild-moderate patients (P=0.037). Delivery route has no impact on the efficacy of FMT in UC and CD. Based on current available evidence, a trend was observed towards higher clinical remission rate of frozen stool FMT than that of fresh stool for UC, while there was no significant difference between fresh and frozen FMT for CD. The optimal donor stool for FMT is still uncertain. Meta-analysis of RCTs showed that FMT treatment achieved significantly higher clinical remission rate than placebo for UC (28% versus 9%, P=0.0003).

Conclusion

FMT is an effective and safe therapy for both paediatric and adult IBD; fresh or frozen donor stool, delivery route, and antibiotic pretreatment or not have no impact on the efficacy of FMT in IBD. FMT might be a potential rescue therapy and even an initial standardized therapy for IBD. However, few data exist on long-term safety and efficacy and further validation is needed.

The Value of Fecal Microbiota Transplantation in the Treatment of Ulcerative Colitis Patients: A Systematic Review and Meta-Analysis

Background and Aims

Fecal microbiota transplantation (FMT) has challenged the traditional management of ulcerative colitis (UC) in recent years, while it remained controversial. We aimed to provide a systematic protocol of FMT treatment on UC.

Methods

Studies reporting on FMT treatment in UC patients were performed. A fixed-effect model was used to assess the efficacy of FMT.

Results

Eighteen studies were enrolled (n = 446). A pooled proportion of patients who received FMT had a significant efficacy compared to the placebo group (odds ratio (OR): 2.73, P = 0.002) with a low risk of heterogeneity (P = 0.59, I² = 0%). The Mayo score decreased to 5 points in a state of mild–moderate activity after FMT treatment, and the optimal range of the Mayo score baseline was 6–9 for FMT administration. Then, the baseline of the Shannon diversity index (SDI) had a negative correlation with the clinical response rate (R = −0.992, P = 0.08) or remission rate (R = −0.998, P = 0.036), and the optimal diversity of bacteria was at 7 days to one month. Moreover, the colonoscopy delivery and unrelated fecal donor had slight superiorities of FMT treatment.

Conclusion

FMT treatment had a higher efficacy and shorter time-point of early assessment of effectiveness on UC patients compared to traditional therapies. And the optimal FMT delivery and donor were colonoscopy delivery and unrelated donor in clinical practice.

Safety, Clinical Response, and Microbiome Findings Following Fecal Microbiota Transplant in Children With Inflammatory Bowel Disease

BACKGROUND

The role of fecal microbiota transplant (FMT) in the treatment of pediatric inflammatory bowel disease (IBD) is unknown. The aims of this study were to assess safety, clinical response, and gut microbiome alterations in children with Crohn's disease (CD), ulcerative colitis (UC), or indeterminate colitis (IC).

METHODS

In this open-label, single-center prospective trial, patients with IBD refractory to medical therapy underwent a single FMT by upper and lower endoscopy. Adverse events, clinical response, gut microbiome, and biomarkers were assessed at baseline, 1 week, 1 month, and 6 months following FMT.

RESULTS

Twenty-one subjects were analyzed, with a median age of 12 years, of whom 57% and 28% demonstrated clinical response at 1 and 6 months post-FMT, respectively. Two CD patients were in remission at 6 months. Adverse events attributable to FMT were mild to moderate and self-limited. Patients prior to FMT showed decreased species diversity and significant microbiome compositional differences characterized by increased Enterobacteriaceae, Enterococcus, Haemophilus, and Fusobacterium compared with donors and demonstrated increased species diversity at 30 days post-FMT. At 6 months, these changes shifted toward baseline. Clinical responders had a higher relative abundance of Fusobacterium and a lower diversity at baseline, as well as a greater shift toward donor-like microbiome after FMT compared with nonresponders.

CONCLUSIONS

A single FMT is relatively safe and can result in a short-term response in young patients with active IBD. Responders possessed increased Fusobacterium prior to FMT and demonstrated more significant microbiome changes compared with nonresponders after FMT. Microbiome characteristics may help in predicting response.

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

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

Faecal microbiota transplantation: a regulatory hurdle?

During faecal microbiota transplantation, stool from a healthy donor is transplanted to treat a variety of dysbiosis-associated gut diseases. Competent authorities are faced with the challenge to provide adequate regulation. Currently, regulatory harmonization is completely lacking and authorities apply non-existing to most stringent requirements. A regulatory approach for faecal microbiota transplantation could be inserting faecal microbiota transplantation in the gene-, cell- and tissue regulations, including the hospital exemption system in the European Advanced Therapy Medicinal Products regulation, providing a pragmatic and efficacy-risk balanced approach and granting all patients as a matter of principle access to this therapy.

Systematic Review and Meta-analysis: Fecal Microbiota Transplantation for Treatment of Active Ulcerative Colitis

BACKGROUND

Changes in the colonic microbiota may play a role in the pathogenesis of ulcerative colitis (UC) and restoration of healthy gut microbiota may ameliorate disease. A systematic review and meta-analysis was conducted to assess fecal microbiota transplantation (FMT) as a treatment for active UC.

METHODS

A literature search was conducted to identify high-quality studies of FMT as a treatment for patients with UC. The primary outcome was combined clinical remission and endoscopic remission or response. Secondary outcomes included clinical remission, endoscopic remission, and serious adverse events. Odds ratios with 95% confidence intervals (CIs) are reported.

RESULTS

Overall, 4 studies with 277 participants were eligible for inclusion. Among 4 randomized controlled trials, FMT was associated with higher combined clinical and endoscopic remission compared with placebo (risk ratio UC not in remission was 0.80; 95% CI: 0.71-0.89) with a number needed to treat of 5 (95% CI: 4-10). There was no statistically significant increase in serious adverse events with FMT compared with controls (risk ratio adverse event was 1.4; 95% CI: 0.55-3.58).

CONCLUSIONS

Among randomized controlled trials, short-term use of FMT shows promise as a treatment to induce remission in active UC based on the efficacy and safety observed. However, there remain many unanswered questions that require further research before FMT can be considered for use in clinical practice.

Systematic review with meta-analysis: faecal microbiota transplantation for the induction of remission for active ulcerative colitis

BACKGROUND

Faecal microbiota transplantation (FMT) is emerging as a novel therapy for ulcerative colitis (UC). Interpretation of efficacy of FMT for UC is complicated by differences among studies in blinding, FMT administration procedures, intensity of therapy and donor stool processing methods.

AIM

To determine whether FMT is effective and safe for the induction of remission in active UC.

METHODS

Medline (Ovid), Embase and the Cochrane Library were searched from inception through February 2017. Original studies reporting remission rates following FMT for active UC were included. All study designs were included in the systematic review and a meta-analysis performed including only randomised controlled trials (RCTs).

RESULTS

There were 14 cohort studies and four RCTs that used markedly different protocols. In the meta-analysis of RCTs, clinical remission was achieved in 39 of 140 (28%) patients in the donor FMT groups compared with 13 of 137 (9%) patients in the placebo groups; odds ratio 3.67 (95% CI: 1.82-7.39, P<.01). Clinical response was achieved in 69 of 140 (49%) donor FMT patients compared to 38 of 137 (28%) placebo patients; odds ratio 2.48 (95% CI: 1.18-5.21, P=.02). In cohort studies, 39 of 168 (24%; 95% CI: 11%-40%) achieved clinical remission.

CONCLUSIONS

Despite variation in processes, FMT appears to be effective for induction of remission in UC, with no major short-term safety signals. Further studies are needed to better define dose frequency and preparation methods, and to explore its feasibility, efficacy and safety as a maintenance agent.

Management of inflammatory bowel disease with Clostridium difficile infection

AIM

To address the management of Clostridium difficile (C. difficile) infection (CDI) in the setting of suspected inflammatory bowel disease (IBD)-flare.

METHODS

A systematic search of the Ovid MEDLINE and EMBASE databases by independent reviewers identified 70 articles including a total of 932141 IBD patients or IBD-related hospitalizations.

RESULTS

In those with IBD, CDI is associated with increased morbidity, including subsequent escalation in IBD medical therapy, urgent colectomy and increased hospitalization, as well as excess mortality. Vancomycin-containing regimens are effective first-line therapies for CDI in IBD inpatients. No prospective data exists with regards to the safety or efficacy of initiating or maintaining corticosteroid, immunomodulator, or biologic therapy to treat IBD in the setting of CDI. Corticosteroid use is a risk factor for the development of CDI, while immunomodulators and biologics are not.

CONCLUSION

Strong recommendations regarding when to initiate IBD specific therapy in those with CDI are precluded by a lack of evidence. However, based on expert opinion and observational data, initiation or resumption of immunosuppressive therapy after 48-72 h of targeted antibiotic treatment for CDI may be considered.

Fecal microbiota transplantation is a rescue treatment modality for refractory ulcerative colitis

BACKGROUND

Fecal microbial transplantation (FMT) provides to replace beneficial bacteria with more favorable microbiomes in recipient with dysbiosis. The aim of the present study was to prospectively investigate the efficacy of FMT by assessing the clinical and endoscopic response in patients with ulcerative colitis (UC) who had failed anti-inflammatory and immunosuppressive therapy.

METHODS

In this prospective and uncontrolled study, 30 patients with UC were included. All medications except mesalazine were stopped 4 weeks before FMT. Colonoscopy was performed both before and after FMT. To assess the efficacy of FMT, Mayo scores were calculated at week 0 and week 12. A total of 500 mL extracted fresh fecal suspension was administered into the 30 to 40 cm proximal of terminal ileum of recipients.

RESULTS

After FMT, 21 of the (70%) 30 patients showed clinical response, and 13 of the 30 (43.3%) patients achieved clinical and endoscopic remission at the week 12. Nine patients (30%) were accepted as a nonresponder at the end of the week 12. There was no significant difference among donors concerning both the rate of clinical remission and clinical response. No adverse events were observed in the majority of patients during FMT and 12 weeks follow-up. Seven patients (23.3%) experienced mild adverse events such as nausea, vomiting, abdominal pain, diarrhea, and fewer after FMT.

CONCLUSION

FMT could be considered as a promising rescue treatment modality before surgery in patients with refractory UC. Besides, FMT also appears to be definitely safer and more tolerable than the immunosuppressive therapy in patients with UC (NCT02575040).

Fecal microbiota transplantation in ulcerative colitis

With the continuous improvement of the living standards of Chinese people, the incidence of ulcerative colitis in China has been increasing. Recent studies have demonstrated that the pathogenesis of ulcerative colitis is closely related with the aberrance of intestinal microbiota of the host. Intestinal microbiota is composed of 10¹³-10¹⁴ bacterial cells, whose number is ten times of the number of human cells in the body. These bacteria significantly affect the health of the body, and are regarded as a virtual organ of the body. The pathogenesis of ulcerative colitis is related to the malfunction of the host immunity. Intestinal microbiota regulates the immune activities and hence affects the onset of ulcerative colitis. Fecal microbiota transplantation is an ancient regimen which is able to repopulate the intestinal microbiota of the recipient, and thus to rectify the aberrant immune function and to restore the physiological function of the body. In the current paper, we review the relationship between intestinal microbiota and ulcerative colitis and the effects of fecal microbiota transplantation on ulcerative colitis.

Recent advances in understanding and managing Crohn's disease

There is consensus that inflammatory bowel diseases (IBDs) are the result of “dysregulated” immune reactivity towards commensal microorganisms in the intestine. This gut microbiome is clearly altered in IBD, but its primary or secondary role is still debated. The focus has shifted from adaptive to innate immunity, with its multitude of receptor molecules (Toll-like and NOD receptors) and antibacterial effector molecules (defensins, cathelicidin, and others). The latter appear to be at least partly deficient at different intestinal locations. Host genetics also support the notion that microbe–host interaction at the mucosa is the prime site of pathogenesis. In contrast, even the latest therapeutic antibodies are directed against secondary targets like cytokines and integrins identified decades ago. These so-called “biologicals” have disappointing long-term results, with the majority of patients not achieving remission in the long run. A promising approach is the development of novel drugs like defensin-derived molecules that substitute for the missing endogenous antibacterials.