Returning to Nature for the Next Generation of Antimicrobial Therapeutics

Antibiotics found in and inspired by nature are life-saving cures for bacterial infections and have enabled modern medicine. However, the rise in resistance necessitates the discovery and development of novel antibiotics and alternative treatment strategies to prevent the return to a pre-antibiotic era. Once again, nature can serve as a source for new therapies in the form of natural product antibiotics and microbiota-based therapies. Screening of soil bacteria, particularly actinomycetes, identified most of the antibiotics used in the clinic today, but the rediscovery of existing molecules prompted a shift away from natural product discovery. Next-generation sequencing technologies and bioinformatics advances have revealed the untapped metabolic potential harbored within the genomes of environmental microbes. In this review, we first highlight current strategies for mining this untapped chemical space, including approaches to activate silent biosynthetic gene clusters and in situ culturing methods. Next, we describe how using live microbes in microbiota-based therapies can simultaneously leverage many of the diverse antimicrobial mechanisms found in nature to treat disease and the impressive efficacy of fecal microbiome transplantation and bacterial consortia on infection. Nature-provided antibiotics are some of the most important drugs in human history, and new technologies and approaches show that nature will continue to offer valuable inspiration for the next generation of antibacterial therapeutics.

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.

Review article: the future of microbiome-based therapeutics

BACKGROUND

From consumption of fermented foods and probiotics to emerging applications of faecal microbiota transplantation, the health benefit of manipulating the human microbiota has been exploited for millennia. Despite this history, recent technological advances are unlocking the capacity for targeted microbial manipulation as a novel therapeutic.

AIM

This review summarises the current developments in microbiome-based medicines and provides insight into the next steps required for therapeutic development.

METHODS

Here we review current and emerging approaches and assess the capabilities and weaknesses of these technologies to provide safe and effective clinical interventions. Key literature was identified through Pubmed searches with the following key words, 'microbiome', 'microbiome biomarkers', 'probiotics', 'prebiotics', 'synbiotics', 'faecal microbiota transplant', 'live biotherapeutics', 'microbiome mimetics' and 'postbiotics'.

RESULTS

Improved understanding of the human microbiome and recent technological advances provide an opportunity to develop a new generation of therapies. These therapies will range from dietary interventions, prebiotic supplementations, single probiotic bacterial strains, human donor-derived faecal microbiota transplants, rationally selected combinations of bacterial strains as live biotherapeutics, and the beneficial products or effects produced by bacterial strains, termed microbiome mimetics.

CONCLUSIONS

Although methods to identify and refine these therapeutics are continually advancing, the rapid emergence of these new approaches necessitates accepted technological and ethical frameworks for measurement, testing, laboratory practices and clinical translation.

Donor-dependent fecal microbiota transplantation efficacy against necrotizing enterocolitis in preterm pigs

The development of necrotizing enterocolitis (NEC), a life-threatening inflammatory bowel disease affecting preterm infants, is connected with gut microbiota dysbiosis. Using preterm piglets as a model for preterm infants we recently showed that fecal microbiota transplantation (FMT) from healthy suckling piglet donors to newborn preterm piglets decreased the NEC risk. However, in a follow-up study using donor stool from piglets recruited from another farm, this finding could not be replicated. This allowed us to study donor-recipient microbiota dynamics in a controlled model system with a clear difference in NEC phenotype. Preterm piglets (n = 38) were randomly allocated to receive control saline (CON), or rectal FMT using either the ineffective (FMT1) or the effective donor stool (FMT2). All animals were followed for four days before necropsy and gut pathological evaluation. Donor and recipient colonic gut microbiota (GM) were analyzed by 16 S rRNA gene amplicon sequencing and shotgun metagenomics. As expected, only FMT2 recipients were protected against NEC. Both FMT groups had shifted GM composition relative to CON, but FMT2 recipients had a higher lactobacilli relative abundance compared to FMT1. Limosilactobacillus reuteri and Lactobacillus crispatus strains of FMT recipients showed high phylogenetic similarity with their respective donors, indicating engraftment. Moreover, the FMT2 group had a higher lactobacilli replication rate and harbored specific glycosaminoglycan-degrading Bacteroides. In conclusion, subtle species-level donor differences translate to major changes in engraftment dynamics and the ability to prevent NEC. This could have implications for proper donor selection in future FMT trials for NEC prevention.

The Role of Fecal Microbiota Transplantation in the Treatment of Inflammatory Bowel Disease

The exact pathogenesis of inflammatory bowel disease (IBD) is still not completely understood. It is hypothesized that a genetic predisposition leads to an exaggerated immune response to an environmental trigger, leading to uncontrolled inflammation. As there is no known causative treatment, current management strategies for inflammatory bowel disease focus on correcting the excessive immune response to environmental (including microbial) triggers. In recent years, there has been growing interest in new avenues of treatment, including targeting the microbial environment itself. Fecal microbiota transplantation (FMT) is a novel treatment modality showing promising results in early studies. The article discusses the rationale for the use of FMT in inflammatory bowel disease and the yet-unresolved questions surrounding its optimal use in practice.

Fecal microbiota transplantation for recurrent Clostridioides difficile infection in patients with concurrent ulcerative colitis

Treatment of recurrent Clostridioides difficile infection (rCDI) has emerged as an important management dilemma particularly in patients with underlying inflammatory bowel disease (IBD). Fecal microbiota transplantation (FMT) has been used as a safe and highly effective treatment option for rCDI refractory to standard antibiotic therapies. The aim of this study was to report the efficacy of FMT in Iranian rCDI patients with concurrent IBD. A total of seven consecutive patients with ulcerative colitis (UC) who had experienced 3 episodes of rCDI were enrolled in this study. All patients received at least a single FMT administered during colonoscopy by direct infusion of minimally processed donor stool. Patients were followed for a minimum of 6 months for assessment of treatment efficacy and adverse events (AEs) attributable to FMT. All 7 UC patients (100%) experienced a durable clinical response to a single FMT following 2 months after the procedure. One patient received a second FMT in which a successful resolution of rCDI was ultimately achieved. No serious AEs from FMT were noted. FMT through colonoscopy was a safe, simple and effective alternative treatment approach for rCDI in patients with underlying IBD. However, its use and efficacy should be pursued in long-term prospective controlled trials.

What Makes a Successful Donor? Fecal Transplant from Anxious-Like Rats Does Not Prevent Spinal Cord Injury-Induced Dysbiosis

Spinal cord injury (SCI) causes gut dysbiosis and an increased prevalence of depression and anxiety. Previous research showed a link between these two consequences of SCI by using a fecal transplant from healthy rats which prevented both SCI-induced microbiota changes and the subsequent development of anxiety-like behaviour. However, whether the physical and mental state of the donor are important factors in the efficacy of FMT therapy after SCI remains unknown. In the present study, rats received a fecal transplant following SCI from uninjured donors with increased baseline levels of anxiety-like behaviour and reduced proportion of Lactobacillus in their stool. This fecal transplant increased intestinal permeability, induced anxiety-like behaviour, and resulted in minor but long-term alterations in the inflammatory state of the recipients compared to vehicle controls. There was no significant effect of the fecal transplant on motor recovery in rehabilitative training, suggesting that anxiety-like behaviour did not affect the motivation to participate in rehabilitative therapy. The results of this study emphasize the importance of considering both the microbiota composition and the mental state of the donor for fecal transplants following spinal cord injury.

An ecological framework to understand the efficacy of fecal microbiota transplantation

Human gut microbiota plays critical roles in physiology and disease. Our understanding of ecological principles that govern the dynamics and resilience of this highly complex ecosystem remains rudimentary. This knowledge gap becomes more problematic as new approaches to modifying this ecosystem, such as fecal microbiota transplantation (FMT), are being developed as therapeutic interventions. Here we present an ecological framework to understand the efficacy of FMT in treating conditions associated with a disrupted gut microbiota, using the recurrent Clostridioides difficile infection as a prototype disease. This framework predicts several key factors that determine the efficacy of FMT. Moreover, it offers an efficient algorithm for the rational design of personalized probiotic cocktails to decolonize pathogens. We analyze data from both preclinical mouse experiments and a clinical trial of FMT to validate our theoretical framework. The presented results significantly improve our understanding of the ecological principles of FMT and have a positive translational impact on the rational design of general microbiota-based therapeutics.

Here, the authors present a theoretical framework based on community ecology and network science to investigate the efficacy of fecal microbiota transplantation in conditions associated with a disrupted gut microbiota, using the recurrent Clostridioides difficile infection as a prototype disease.

Matching between Donors and Ulcerative Colitis Patients Is Important for Long-Term Maintenance after Fecal Microbiota Transplantation

We previously demonstrated that fresh fecal microbiota transplantation (FMT) following triple antibiotic therapy (amoxicillin, fosfomycin, metronidazole (AFM); A-FMT) resulted in effective colonization of Bacteroidetes species, leading to short-term clinical response in ulcerative colitis (UC). Its long-term efficacy and criteria for donor selection are unknown. Here, we analyzed the long-term efficacy of A-FMT compared to AFM monotherapy (mono-AFM). AFM was administered to patients with mild to severe UC for 2 weeks until 2 days before fresh FMT. Clinical response and efficacy maintenance were defined by the decrease and no exacerbation in clinical activity index. The population for intention-to-treat analysis comprised 92 patients (A-FMT, n = 55; mono-AFM, n = 37). Clinical response was observed at 4 weeks post-treatment (A-FMT, 56.3%; mono-AFM, 48.6%). Maintenance rate of responders at 24 months post-treatment was significantly higher with A-FMT than mono-AFM (p = 0.034). Significant differences in maintenance rate according to the age difference between donors and patients were observed. Additionally, sibling FMT had a significantly higher maintenance rate than parent–child FMT. Microbial analysis of patients who achieved long-term maintenance showed that some exhibited similarity to their donors, particularly Bacteroidetes species. Thus, A-FMT exhibited long-term efficacy. Therefore, matching between donors and UC patients may be helpful in effectively planning the FMT regimen.

Improving Risk-Benefit in Faecal Transplantation through Microbiome Screening

Faecal microbiota transplantation (FMT) has been shown to be effective in the treatment of a growing number of conditions, and its clinical use continues to rise. However, recent cases of antibiotic-resistant pathogen transmission through FMT, resulting in at least one case of fatal sepsis, highlight the need to reevaluate current donor screening practices. Commensal gut microbes profoundly influence infection risk but are not routinely assessed in donor stool. Extending the assessment of donor material beyond pathogen populations to include the composition and structure of the wider faecal microbiota has the potential to reduce infectious complications in FMT recipients.

Framework for rational donor selection in fecal microbiota transplant clinical trials

Early clinical successes are driving enthusiasm for fecal microbiota transplantation (FMT), the transfer of healthy gut bacteria through whole stool, as emerging research is linking the microbiome to many different diseases. However, preliminary trials have yielded mixed results and suggest that heterogeneity in donor stool may play a role in patient response. Thus, clinical trials may fail because an ineffective donor was chosen rather than because FMT is not appropriate for the indication. Here, we describe a conceptual framework to guide rational donor selection to increase the likelihood that FMT clinical trials will succeed. We argue that the mechanism by which the microbiome is hypothesized to be associated with a given indication should inform how healthy donors are selected for FMT trials, categorizing these mechanisms into four disease models and presenting associated donor selection strategies. We next walk through examples based on previously published FMT trials and ongoing investigations to illustrate how donor selection might occur in practice. Finally, we show that typical FMT trials are not powered to discover individual taxa mediating patient responses, suggesting that clinicians should develop targeted hypotheses for retrospective analyses and design their clinical trials accordingly. Moving forward, developing and applying novel clinical trial design methodologies like rational donor selection will be necessary to ensure that FMT successfully translates into clinical impact.

The Super-Donor Phenomenon in Fecal Microbiota Transplantation

Fecal microbiota transplantation (FMT) has become a highly effective bacteriotherapy for recurrent Clostridium difficile infection. Meanwhile the efficacy of FMT for treating chronic diseases associated with microbial dysbiosis has so far been modest with a much higher variability in patient response. Notably, a number of studies suggest that FMT success is dependent on the microbial diversity and composition of the stool donor, leading to the proposition of the existence of FMT super-donors. The identification and subsequent characterization of super-donor gut microbiomes will inevitably advance our understanding of the microbial component of chronic diseases and allow for more targeted bacteriotherapy approaches in the future. Here, we review the evidence for super-donors in FMT and explore the concept of keystone species as predictors of FMT success. Possible effects of host-genetics and diet on FMT engraftment and maintenance are also considered. Finally, we discuss the potential long-term applicability of FMT for chronic disease and highlight how super-donors could provide the basis for dysbiosis-matched FMTs.

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.

Protocol for Fecal Microbiota Transplantation in Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis. Biomed Res Int. 2018;2018:8941340. [PMID: 30302341 PMCID: PMC6158944 DOI: 10.1155/2018/8941340]

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.

Competitively Selected Donor Fecal Microbiota Transplantation: Butyrate Concentration and Diversity as Measures of Donor Quality

In this prospective cohort study, we examine the feasibility of a protocol to optimize microbiota for fecal microbiota transplantation (FMT). Donor stool metrics generally accepted as markers of gut health were used to select a stool donor based on superior microbial diversity, balanced constitution of Bacteroidetes versus Firmicutes and high concentration of fecal butyrate. Selected donor microbiota was then administered via FMT. A total of 10 patients with median age of 12 years with recurrent Clostridium difficile infection received the intervention. The rate of recurrence-free resolution with 1-2 FMTs was 100% at Week 10. With a single FMT, 80% of patients cleared Clostridium difficile infection without recurrence, whereas 20% of patients required a single re-treatment. No serious adverse events occurred. Microbiota sequencing revealed that recipients' gut microbiota phylogenic diversity increased by 72-hours post-transplantation, with sustainment over 10-week follow-up. This study highlights the feasibility of purposefully selecting the most ideal microbiota for transplantation.

Applying fecal microbiota transplantation (FMT) to treat recurrent Clostridium difficile infections (rCDI) in children

BACKGROUND

Fecal Microbiota Transplantation (FMT) is an innovative means of treating recurrent Clostridium difficile infection (rCDI), through restoration of gut floral balance. However, there is a lack of data concerning the efficacy of FMT and its impact on the gut microbiome among pediatric patients. This study analyzes clinical outcomes and microbial community composition among 15 pediatric patients treated for rCDI via FMT.

METHODS

This is a prospective, observational, pilot study of 15 children ≤18 years, who presented for rCDI and who met inclusion criteria for FMT at a pediatric hospital and pediatric gastroenterology clinic. Past medical history and demographics were recorded at enrollment and subsequent follow-up. Specimens of the donors' and the patients' pre-FMT and post-FMT fecal specimen were collected and used to assess microbiome composition via 16S rRNA gene sequencing.

RESULTS

FMT successfully prevented rCDI episodes for minimum of 3 months post-FMT in all patients, with no major adverse effects. Three patients reported continued GI bleeding; however, all three also had underlying Inflammatory Bowel Disease (IBD). Our analyses confirm a significant difference between pre-and post-FMT gut microbiome profiles (Shannon diversity index), whereas no significant difference was observed between post-FMT and donor microbiome profiles. At the phyla level, post-FMT profiles showed significantly increased levels of Bacteroidetes and significantly decreased levels of Proteobacteria. Subjects with underlying IBD showed no difference in their pre-and post-FMT profiles.

CONCLUSION

The low rate of recurrence or re-infection by C. difficile, coupled with minimal adverse effects post-FMT, suggests that FMT is a viable therapeutic means to treat pediatric rCDI. Post-FMT microbiomes are different from pre-FMT microbiomes, and similar to those of healthy donors, suggesting successful establishment of a healthier microbiome.

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.