Systematic review with meta-analysis: long-term outcomes of faecal microbiota transplantation for Clostridium difficile infection

Impact of Fecal Microbiota Transplantation on Obesity and Metabolic Syndrome-A Systematic Review

Fecal microbiota transplantation (FMT) is a gut microbial-modulation strategy that has been investigated for the treatment of a variety of human diseases, including obesity-associated metabolic disorders. This study appraises current literature and provides an overview of the effectiveness and limitations of FMT as a potential therapeutic strategy for obesity and metabolic syndrome (MS). Five electronic databases and two gray literature sources were searched up to 10 December 2018. All interventional and observational studies that contained information on the relevant population (adult patients with obesity and MS), intervention (receiving allogeneic FMT) and outcomes (metabolic parameters) were eligible. From 1096 unique citations, three randomized placebo-controlled studies (76 patients with obesity and MS, body mass index = 34.8 ± 4.1 kg/m², fasting plasma glucose = 5.8 ± 0.7 mmol/L) were included for review. Studies reported mixed results with regards to improvement in metabolic parameters. Two studies reported improved peripheral insulin sensitivity (rate of glucose disappearance, RD) at 6 weeks in patients receiving donor FMT versus patients receiving the placebo control. In addition, one study observed lower HbA1c levels in FMT patients at 6 weeks. No differences in fasting plasma glucose, hepatic insulin sensitivity, body mass index (BMI), or cholesterol markers were observed between two groups across all included studies. While promising, the influence of FMT on long-term clinical endpoints needs to be further explored. Future studies are also required to better understand the mechanisms through which changes in gut microbial ecology and engraftment of microbiota affect metabolic outcomes for patients with obesity and MS. In addition, further research is needed to better define the optimal fecal microbial preparation, dosing, and method of delivery.

Clostridioides difficile: diagnosis and treatments

Clostridioides difficile (formerly Clostridium) is a major cause of healthcare associated diarrhea, and is increasingly present in the community. Historically, C difficile infection was considered easy to diagnose and treat. Over the past two decades, however, diagnostic techniques have changed in line with a greater understanding of the physiopathology of C difficile infection and the use of new therapeutic molecules. The evolution of diagnosis showed there was an important under- and misdiagnosis of C difficile infection, emphasizing the importance of algorithms recommended by European and North American infectious diseases societies to obtain a reliable diagnosis. Previously, metronidazole was considered the reference drug to treat C difficile infection, but more recently vancomycin and other newer drugs are shown to have higher cure rates. Recurrence of infection represents a key parameter in the evaluation of new drugs, and the challenge is to target the right population with the adapted therapeutic molecule. In multiple recurrences, fecal microbiota transplantation is recommended. New approaches, including antibodies, vaccines, and new molecules are already available or in the pipeline, but more data are needed to support the inclusion of these in practice guidelines. This review aims to provide a baseline for clinicians to understand and stratify their choice in the diagnosis and treatment of C difficile infection based on the most recent data available.

The role of the microbiome for human health: from basic science to clinical applications

The 2017 annual symposium organized by the University Medical Center Groningen in The Netherlands focused on the role of the gut microbiome in human health and disease. Experts from academia and industry examined interactions of prebiotics, probiotics, or vitamins with the gut microbiome in health and disease, the development of the microbiome in early-life and the role of the microbiome on the gut–brain axis. The gut microbiota changes dramatically during pregnancy and intrinsic factors (such as stress), in addition to extrinsic factors (such as diet, and drugs) influence the composition and activity of the gut microbiome throughout life. Microbial metabolites, e.g. short-chain fatty acids affect gut–brain signaling and the immune response. The gut microbiota has a regulatory role on anxiety, mood, cognition and pain which is exerted via the gut–brain axis. Ingestion of prebiotics or probiotics has been used to treat a range of conditions including constipation, allergic reactions and infections in infancy, and IBS. Fecal microbiota transplantation (FMT) highly effective for treating recurrent Clostridium difficile infections. The gut microbiome affects virtually all aspects of human health, but the degree of scientific evidence, the models and technologies and the understanding of mechanisms of action vary considerably from one benefit area to the other. For a clinical practice to be broadly accepted, the mode of action, the therapeutic window, and potential side effects need to thoroughly be investigated. This calls for further coordinated state-of-the art research to better understand and document the human gut microbiome’s effects on human health.

Long-term durability and safety of fecal microbiota transplantation for recurrent or refractory Clostridioides difficile infection with or without antibiotic exposure

Fecal microbiota transplant (FMT) is a safe and effective treatment for recurrent or refractory Clostridioides (Clostridium) difficile infection (RCDI) in the short term. However, there are a paucity of data on long-term durability and safety of FMT. The aim of this study is to determine the long-term efficacy and safety of FMT for RCDI. Ninety-four patients underwent FMT via retention enema for RCDI between 2008 and 2012 and completed a follow-up questionnaire 4 to 8 years following the last FMT. Of these, 32 were unreachable and 37 were deceased; 23 of the remaining 25 participants completed the survey. No CDI recurrences were reported in patients treated with FMT; 12 of the 23 participants (52.2%) received at least one course of non-CDI antibiotic(s). Nine participants (40.9%) received probiotics and 4 (17.4%) received both non-CDI antibiotics and probiotics. All 23 participants rated their overall health compared with pre-FMT. Current health was considered "much better" in 17 patients (73.9%); "somewhat better" in 3 patients (13.0%); and "about the same" in 3 patients (13.0%). A total of 11 participants (47.8%) reported an increase in weight of more than 5 kg (kg) post-FMT and 9 participants (39.1%) reported no change in weight (± 5 kg). Four of the 23 participants (17.4%) reported improvement or resolution (undifferentiated colitis, n = 1; Crohn's disease, n = 2; ulcerative colitis, n = 1) of pre-existing gastrointestinal condition following FMT. Eight of 23 participants (34.8%) experienced new medical condition(s) post-FMT. The long-term efficacy (48-96 months) of FMT for RCDI appears to be durable even after non-CDI antibiotic use. Thirty percent had improvement of their pre-existing medical conditions following FMT; 73.9% reported "much better" overall health following FMT.

Fecal microbiota transplantation beyond Clostridioides difficile infections

The importance of the commensal microbiota to human health and well-being has become increasingly evident over the past decades. From a therapeutic perspective, the popularity of fecal microbiota transplantation (FMT) to restore a disrupted microbiota and amend imbalances has increased. To date, most clinical experience with FMT originates from the treatment of recurrent or refractory Clostridioides difficile infections (rCDI), with resolution rates up to 90%. In addition to CDI, a role for the intestinal microbiome has been implicated in several disorders. FMT has been tested in several randomized controlled trials for the treatment of inflammatory bowel disease, irritable bowel disease and constipation with mixed results. FMT has also been explored for extra-gastrointestinal disorders such as metabolic syndrome, hepatic encephalopathy and graft-versus-host disease. With the exception of recurrent CDI, FMT is currently used in experimental settings only and should not yet be offered as standard care. In addition, it is critical to further standardize and optimize procedures for FMT preparation. This includes determination of active components of FMT to develop (personalized) approaches to treat disease.

Status of vaccine research and development for Clostridium difficile

Clostridium difficile associated disease is fundamentally associated with dysbiosis of the gut microbiome as a consequence of antibiotic use. This is because this sporulating, obligate anaerobe germinates and proliferates rapidly in the dysbiotic gut, which is an indirect consequence of their use. During its growth, C. difficile produces two toxins, toxin A (TcdA) and toxin B (TcdB), which are responsible for the majority of clinical symptoms associated with the disease. Three parenterally delivered vaccines, based on detoxified or recombinant forms of these toxins, have undergone or are undergoing clinical trials. Each offers the opportunity to generate high titres of toxin neutralising antibodies. Whilst these data suggest these vaccines may reduce primary symptomatic disease, they do not in their current form reduce the capacity of the organism to persist and shed from the vaccinated host. The current progress of vaccine development is considered with advantages and limitations of each highlighted. In addition, several alternative approaches are described that seek to limit C. difficile germination, colonisation and persistence. It may yet prove that the most effective treatments to limit infection, disease and spread of the organism will require a combination of therapeutic approaches. The potential use and efficacy of these vaccines in low and middle income countries will be depend on the development of a cost effective vaccine and greater understanding of the distribution and extent of disease in these countries.

An insight into gut microbiota and its functionalities

Gut microbiota has evolved along with their hosts and is an integral part of the human body. Microbiota acquired at birth develops in parallel as the host develops and maintains its temporal stability and diversity through adulthood until death. Recent developments in genome sequencing technologies, bioinformatics and culturomics have enabled researchers to explore the microbiota and in particular their functions at more detailed level than before. The accumulated evidences suggest that though a part of the microbiota is conserved, the dynamic members vary along the gastrointestinal tract, from infants to elderly, primitive tribes to modern societies and in different health conditions. Though the gut microbiota is dynamic, it performs some basic functions in the immunological, metabolic, structural and neurological landscapes of the human body. Gut microbiota also exerts significant influence on both physical and mental health of an individual. An in-depth understanding of the functioning of gut microbiota has led to some very exciting developments in therapeutics, such as prebiotics, probiotics, drugs and faecal transplantation leading to improved health.

Fecal microbiota transplantation for treatment of recurrent C. difficile infection: An updated randomized controlled trial meta-analysis

OBJECTIVES

Although systematic evaluation has confirmed the efficacy of fresh fecal microbiota transplantation (FMT) for treatment of recurrent and/or refractory and/or relapse C. difficile infection (RCDI), it lacks the support of well-designed randomized controlled trials (RCTs), and the latest guidelines do not optimize the management of FMT. In this paper, we focus on an in-depth study of fresh FMT and fecal infusion times to guide clinical practice.

METHODS

We reviewed studies in PubMed, Medline, Embase, the Cochrane library and Cochrane Central written in English. The retrieval period was from the establishment of the databases to September 20th, 2018. The retrieval objects were published RCTs of RCDI treated by fresh FMT. The intervention group was fresh FMT group, while the control group included antibiotic therapy or placebo or frozen FMT or capsule. The primary and secondary outcomes were the clinical remission of diarrhea without relapse after 8-17 weeks and the occurrence of severe adverse events, respectively. Subgroup analysis analyzed the effect of single and multiple fecal infusions. Two authors independently completed the information extraction and assessed risk of bias and overall quality of the evidence.

RESULTS

8 randomized controlled trials met the inclusion criteria, involving 537 patients (273 in the fresh FMT group and 264 in the control group). The recurrence rate of clinical diarrhea in the fresh FMT group was 11.0% (30/273), which was significantly lower than the control group (24.6%, 65/264; P < 0.05); the pooled relative risk (RR) was 0.38 (95%CI:0.16-0.87; I2 = 67%; P = 0.02) in the fresh FMT group, and the clinical heterogeneity was significant and random effects model was used; However, there was no significant difference neither for the effect of antibiotic treatment/frozen feces transplanted by enema (RR = 1.07; 95%CI: 0.64-1.80; I2 = 0%; P = 0.79) or capsule/frozen feces transplanted by colonoscopy (RR = 0.42; 95%CI: 0.05-3.94; I2 = 43%; P = 0.45) compared with fresh FMT. The subgroup analysis showed that FMT by multiple infusions could effectively and significantly (RR = 0.24; 95%CI:0.10-0.58; I2 = 0%; P = 0.001) improve the clinical diarrhea remission rate. Most mild to moderate adverse events caused by FMT were self-limited and could be quickly alleviated; no severe adverse events happened because of FMT.

CONCLUSIONS

Overall, the use of fresh feces for bacterial transplantation was the best efficiency for RCDI compared to antibiotic therapy or placebo. The fecal transmission method by enema was not ideal, but capsules or frozen feces transported by colonoscopy could be an alternative treatment compared to fresh FMT. For patients with severe RCDI, multiple fecal transplants can effectively improve their diarrhea remission rate. The focus of future research should be on how to standardize the production of capsules or frozen feces to better guide the clinical management of RCDI patients by FMT.

Gastrointestinal Tract Disorders in Older Age

Considering an increase in the life expectancy leading to a rise in the elderly population, it is important to recognize the changes that occur along the process of aging. Gastrointestinal (GI) changes in the elderly are common, and despite some GI disorders being more prevalent in the elderly, there is no GI disease that is limited to this age group. While some changes associated with aging GI system are physiologic, others are pathological and particularly more prevalent among those above age 65 years. This article reviews the most important GI disorders in the elderly that clinicians encounter on a daily basis. We highlight age-related changes of the oral cavity, esophagus, stomach, small and large bowels, and the clinical implications of these changes. We review epidemiology and pathophysiology of common diseases, especially as they relate to clinical manifestation in elderly. Details regarding management of specific disease are discussed in detail if they significantly differ from the management for younger groups or if they are associated with significant challenges due to side effects or polypharmacy. Cancers of GI tract are not included in the scope of this article.

Effect of Fecal Microbiota Transplantation on 8-Week Remission in Patients With Ulcerative Colitis: A Randomized Clinical Trial

IMPORTANCE

High-intensity, aerobically prepared fecal microbiota transplantation (FMT) has demonstrated efficacy in treating active ulcerative colitis (UC). FMT protocols involving anaerobic stool processing methods may enhance microbial viability and allow efficacy with a lower treatment intensity.

OBJECTIVE

To assess the efficacy of a short duration of FMT therapy to induce remission in UC using anaerobically prepared stool.

DESIGN, SETTING, AND PARTICIPANTS

A total of 73 adults with mild to moderately active UC were enrolled in a multicenter, randomized, double-blind clinical trial in 3 Australian tertiary referral centers between June 2013 and June 2016, with 12-month follow-up until June 2017.

INTERVENTIONS

Patients were randomized to receive either anaerobically prepared pooled donor FMT (n = 38) or autologous FMT (n = 35) via colonoscopy followed by 2 enemas over 7 days. Open-label therapy was offered to autologous FMT participants at 8 weeks and they were followed up for 12 months.

MAIN OUTCOMES AND MEASURES

The primary outcome was steroid-free remission of UC, defined as a total Mayo score of ≤2 with an endoscopic Mayo score of 1 or less at week 8. Total Mayo score ranges from 0 to 12 (0 = no disease and 12 = most severe disease). Steroid-free remission of UC was reassessed at 12 months. Secondary clinical outcomes included adverse events.

RESULTS

Among 73 patients who were randomized (mean age, 39 years; women, 33 [45%]), 69 (95%) completed the trial. The primary outcome was achieved in 12 of the 38 participants (32%) receiving pooled donor FMT compared with 3 of the 35 (9%) receiving autologous FMT (difference, 23% [95% CI, 4%-42%]; odds ratio, 5.0 [95% CI, 1.2-20.1]; P = .03). Five of the 12 participants (42%) who achieved the primary end point at week 8 following donor FMT maintained remission at 12 months. There were 3 serious adverse events in the donor FMT group and 2 in the autologous FMT group.

CONCLUSIONS AND RELEVANCE

In this preliminary study of adults with mild to moderate UC, 1-week treatment with anaerobically prepared donor FMT compared with autologous FMT resulted in a higher likelihood of remission at 8 weeks. Further research is needed to assess longer-term maintenance of remission and safety.

TRIAL REGISTRATION

anzctr.org.au Identifier: ACTRN12613000236796.

Fecal microbiota transplantation: donor relation, fresh or frozen, delivery methods, cost-effectiveness

Fecal microbiota transplantation (FMT) has evolved into a robust and efficient means for treating recurrent Clostridium difficile infection (CDI). Our narrative review looks at the donor selection, preparation, delivery techniques and cost-effectiveness of FMT. We searched electronic databases, including PubMed, MEDLINE, Google Scholar, and Cochrane Databases, for studies that compared the biological effects of donor selection, fresh or frozen fecal preparation, and various delivery techniques. We also evaluated the cost-effectiveness and manually searched references to identify additional relevant studies. Overall, there is a paucity of studies that directly compare outcomes associated with related and non-related stool donors. However, inferences from prior studies indicate that the success of FMT does not depend on the donor-patient relationship. Over time, the use of unrelated donors has increased because of the formation of stool banks and the need to save processing time and capital. However, longitudinal studies are needed to clarify the optimal freezing time before microbial function declines. Several FMT techniques have been developed, such as colonoscopy, enema, nasogastric or nasojejunal tubes, and capsules. The comparable and high efficacy of FMT capsules, combined with their convenience, safety and aesthetically tolerable mode of delivery, makes it an attractive option for many patients. Cost-effective models comparing these various approaches support the use of FMT via colonoscopy as being the best strategy for the treatment of recurrent CDI.

Safety of fecal microbiota transplantation in Chinese children: A single-center retrospective study

BACKGROUND

Fecal microbiota transplantation (FMT) is the administration of fecal bacterial liquid from healthy donors to a recipient’s digestive tract, which is recommended as a therapeutic method for recurrent Clostridium difficile infection (CDI). Many clinical trials focusing on different diseases are in progress. To date, scarce research and long-term follow-up have been conducted on FMT in children or on the proper guidelines. Our center first performed FMT to treat a 13-month-old boy with severe CDI in 2013. Until February 2018, our center had performed 114 pediatric FMT procedures in 49 subjects.

AIM

To investigate the safety of FMT in children.

METHODS

A retrospective study was conducted on 49 patients who underwent 114 FMT treatments at our hospital. All FMT processes followed uniform standards. Adverse events (AEs) related to FMT were divided into short-term (48 h post-FMT) and long-term (3 mo). All potential influencing factors for AEs, such as gender, age, time of FMT infusion, route of administration, disease type, immune function state, and donor relative genetic background, were analyzed as independent factors. The significant independent factors and risk ratio with 95% confidence interval (CI) were assessed by multivariate logistic regression analysis.

RESULTS

Forty-nine patients (mean age 68.1 mo, range 4 to 193 mo) were recruited. Their average follow-up time after the first FMT was 23.1 mo. The incidence of short-term AEs was 26.32% (30/114). The most common short-term AEs were abdominal pain, diarrhea, fever, and vomiting, which were all self-limited and symptom-free within 48 h. Two severe AEs occurred, and one patient died in the fourth week after FMT. All-cause mortality was 2.04%. As independent factors, age (P = 0.006) and immune state (P = 0.002) had significant effects. Age greater than 72 mo seemed to be correlated with more AEs than age 13 to 36 mo (P = 0.04). In multivariate logistic regression analysis, immune state was an independent risk factor for AE occurrence (P = 0.035), and the risk ratio in immunodeficient patients was 3.105 (95%CI: 1.080-8.923).

CONCLUSION

Although FMT was proven to be tolerated in children, we need to be more cautious with immunodeficient patients. The effect on children’s long-term health is unpredictable.

Fecal microbiota transplantation in refractory or recurrent Clostridium difficile infection: a real-life experience in a non-academic center

AIM

this study aimed to describe the efficacy and safety of fecal microbiota transplantation (FMT) for the treatment of refractory and recurrent Clostridium difficile infection (CDI).

METHODS

this was an observational study of patients with refractory or recurrent CDI treated with FMT between June 2014 and January 2017. Primary and secondary outcomes were the resolution of diarrhea without CDI recurrence within two months after one or more FMT. A descriptive analysis was performed.

RESULTS

thirty-four FMT were performed in 28 patients, 88.2% (n = 30) using an upper route with a gastroscopy and 11.8% (n = 4) with colonoscopy; 50% (n = 17) of FMT were due to recurrent CDI and 50% (n = 17) were due to refractory CDI. The overall cure rate of upper FMT was 87.5% (21/24) and 100% (4/4) when colonoscopy was performed. A cure was achieved after one FMT in 88% (22/25) of cases and after two or more FMT in 8% (2/25) of cases, resulting in an overall cure rate of 96% (24/25). No severe adverse events were reported.

CONCLUSION

FMT constitutes an effective and safe approach for the management of refractory and recurrent CDI, with an overall cure rate of 96% and no reported severe adverse events.

Safety and preliminary efficacy of orally administered lyophilized fecal microbiota product compared with frozen product given by enema for recurrent Clostridium difficile infection: A randomized clinical trial

Background

Fecal microbiota transplantation (FMT) via colonoscopy or enema has become a commonly used treatment of recurrent C. difficile infection (CDI).

Aims

To compare the safety and preliminary efficacy of orally administered lyophilized microbiota product compared with frozen product by enema.

Methods

In a single center, adults with ≥ 3 episodes of recurrent CDI were randomized to receive encapsulated lyophilized fecal microbiota from 100–200 g of donor feces (n = 31) or frozen FMT from 100 g of donor feces (n = 34) by enema. Safety during the three months post FMT was the primary study objective. Prevention of CDI recurrence during the 60 days after FMT was a secondary objective. Fecal microbiome changes were examined in first 39 subjects studied.

Results

Adverse experiences were commonly seen in equal frequency in both groups and did not appear to relate to the route of delivery of FMT. CDI recurrence was prevented in 26 of 31 (84%) subjects randomized to capsules and in 30 of 34 (88%) receiving FMT by enema (p = 0.76). Both products normalized fecal microbiota diversity while the lyophilized orally administered product was less effective in repleting Bacteroidia and Verrucomicrobia classes compared to frozen product via enema.

Conclusions

The route of delivery, oral or rectal, did not influence adverse experiences in FMT. In preliminary evaluation, both routes appeared to show equivalent efficacy, although the dose may need to be higher for lyophilized product. Spore-forming bacteria appear to be the most important engrafting organisms in FMT by the oral route using lyophilized product.

Trial registration

ClinicalTrials.gov NCT02449174

Pre-colonization with the commensal fungus Candida albicans reduces murine susceptibility to Clostridium difficile infection

Clostridium difficile is a major nosocomial pathogen responsible for close to half a million infections and 27,000 deaths annually in the U.S. Preceding antibiotic treatment is a major risk factor for C. difficile infection (CDI) leading to recognition that commensal microbes play a key role in resistance to CDI. Current antibiotic treatment of CDI is only partially successful due to a high rate of relapse. As a result, there is interest in understanding the effects of microbes on CDI susceptibility to support treatment of patients with probiotic microbes or entire microbial communities (e.g., fecal microbiota transplantation). The results reported here demonstrate that colonization with the human commensal fungus Candida albicans protects against lethal CDI in a murine model. Colonization with C. albicans did not increase the colonization resistance of the host. Rather, our findings showed that one effect of C. albicans colonization was to enhance a protective immune response. Mice pre-colonized with C. albicans expressed higher levels of IL-17A in infected tissue following C. difficile challenge compared to mice that were not colonized with C. albicans. Administration of cytokine IL-17A was demonstrated to be protective against lethal murine CDI in mice not colonized with C. albicans. C. albicans colonization was associated with changes in the abundance of some bacterial components of the gut microbiota. Therefore, C. albicans colonization altered the gut ecosystem, enhancing survival after C. difficile challenge. These findings demonstrate a new, beneficial role for C. albicans gut colonization.

Comparing fecal microbiota transplantation to standard-of-care treatment for recurrent Clostridium difficile infection: a systematic review and meta-analysis

BACKGROUND

The use of fecal microbiota transplantation (FMT) as a treatment option for recurrent Clostridium difficile infection (rCDI) is well established. Various studies have used different forms and administration routes for FMT. We performed a systemic review and meta-analysis to update the clinical knowledge about different FMT modalities for curing rCDI compared with medical treatment (MT).

PATIENTS AND METHODS

We searched PubMed and Medline from inception through 10 May 2018 for randomized control trials (RCTs) comparing FMT (fresh or frozen) versus MT. We used Cochrane Collaboration's Risk of Bias tool to assess bias in the RCTs. We estimated odds ratio (OR) with 95% confidence interval (CI) for each outcome using a random effects model. P values of less than 0.05 were considered significant.

RESULTS

We included seven RCTs comprising a total of 543 patients with recurrent CDI. There was a nonsignificant trend toward resolution of diarrhea following a single fresh FMT infusion compared with frozen FMT and MT (OR=2.45, 95% CI=0.78-7.71, P=0.12, I=69%). Subgroup analysis of fresh FMT vs. frozen FMT showed no difference between the two groups (OR=2.13, 95% CI=0.22-20.41, P=0.51, I=61%). Frozen FMT infusion through upper route versus lower route showed no difference (OR=0.62, 95% CI=0.15-2.54, P=0.51, I=0%). There was a nonsignificant trend favoring multiple treatments with FMT versus multiple courses of MT (OR=3.68, 95% CI=0.74-18.22, P=0.11, I=0%).

CONCLUSION

FMT is a promising treatment modality for rCDI compared with MT alone. Different forms and routes of FMT administration seem to be equally efficacious. In future, more well-designed RCTs directed at homogenous FMT preparation and delivery methods are required to validate these findings.

The role of inflammation in temporal shifts in the inflammatory bowel disease mucosal microbiome

Studies of the human intestinal microbiome in patients with inflammatory bowel disease (IBD) consistently show that there are differences (an abnormal or unbalanced microbiome, "dysbiosis") when compared to healthy subjects. We sought to describe changes in the microbiome in individual patients over time, and determine the clinical factors that are associated with significant alteration. Forty-two mucosal biopsies were collected from 20 patients that were spaced an average of 2.4 years apart. These were analysed using bacterial 16S rRNA gene high-throughput sequencing methods. Presence of active inflammation was determined endoscopically and histologically. Inferred metagenomics analysis was conducted using the PICRUSt package. We found that the differences in the microbiome over time in individual patients were greatest in the presence of ongoing intestinal inflammation, as determined by the Yue and Clayton theta distance between sample pairs (adjusted p = 0.00031). Samples from patients with previous abdominal surgery had lower alpha (within sample) diversity compared with those with no prior operations (mean Shannon index 2.083, 2.510 respectively, p = 0.017). There were no changes in the inferred bacterial metagenomic profile. The microbiome in IBD undergoes considerable fluctuation over time. These changes are greatest when there is histologically confirmed inflammation at both time-points.

Rebuilding the Gut Microbiota Ecosystem

A microbial ecosystem in which bacteria no longer live in a mutualistic association is called dysbiotic. Gut microbiota dysbiosis is a condition related with the pathogenesis of intestinal illnesses (irritable bowel syndrome, celiac disease, and inflammatory bowel disease) and extra-intestinal illnesses (obesity, metabolic disorder, cardiovascular syndrome, allergy, and asthma). Dysbiosis status has been related to various important pathologies, and many therapeutic strategies aimed at restoring the balance of the intestinal ecosystem have been implemented. These strategies include the administration of probiotics, prebiotics, and synbiotics; phage therapy; fecal transplantation; bacterial consortium transplantation; and a still poorly investigated approach based on predatory bacteria. This review discusses the various aspects of these strategies to counteract intestinal dysbiosis.

Engineering microbes for targeted strikes against human pathogens

Lack of pathogen specificity in antimicrobial therapy causes non-discriminant microbial cell killing that disrupts the microflora present. As a result, potentially helpful microbial cells are killed along with the pathogen, altering the biodiversity and dynamic interactions within the population. Moreover, the unwarranted exposure of antibiotics to microbes increases the likelihood of developing resistance and perpetuates the emergence of multidrug resistance. Synthetic biology offers an alternative solution where specificity can be conferred to reduce the non-specific, non-targeted activity of currently available antibiotics, and instead provides targeted therapy against specific pathogens and minimising collateral damage to the host's inherent microbiota. With a greater understanding of the microbiome and the available genetic engineering tools for microbial cells, it is possible to devise antimicrobial strategies for novel antimicrobial therapy that are able to precisely and selectively remove infectious pathogens. Herein, we review the strategies developed by unlocking some of the natural mechanisms used by the microbes and how these may be utilised in targeted antimicrobial therapy, with the promise of reducing the current global bane of multidrug antimicrobial resistance.

Microbial taxonomic and metabolic alterations during faecal microbiota transplantation to treat Clostridium difficile infection

OBJECTIVES

This study aimed to examine changes to the microbiota composition and metabolic profiles of seven patients with recurrent Clostridium difficile infection (rCDI), following treatment with faecal microbiota transplant (FMT).

METHODS

16S rDNA sequencing and 1H NMR were performed on faecal samples from the patients (pre-, post-FMT, and follow-up) and the associated donor samples. Sparse partial-least-square analysis was used to identify correlations between the two datasets.

RESULTS

The patients' microbiota post-FMT tended to shift towards the donor microbiota, specifically through proportional increases of Bacteroides, Blautia, and Ruminococcus, and proportional decreases of Enterococcus, Escherichia, and Klebsiella. However, although cured of infection, one patient, who suffers from chronic alcohol abuse, retained the compositional characteristics of the pre-FMT microbiota. Following FMT, increased levels of short-chain fatty acids, particularly butyrate and acetate, were observed in all patients. Sparse partial-least-square analysis confirmed a positive correlation between butyrate and Bacteroides, Blautia, and Ruminococcus, with a negative correlation between butyrate and Klebsiella and Enterococcus.

CONCLUSIONS

Clear differences were observed in the microbiota composition and metabolic profiles between donors and rCDI patients, which were largely resolved in patients following FMT. Increased levels of butyrate appear to be a factor associated with resolution of rCDI.

Effect of Faecal Microbiota Transplantation for Treatment of Clostridium difficile Infection in Patients With Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis of Cohort Studies

BACKGROUND

Evidence concerning the effect of faecal microbiota transplantation [FMT] in Clostridium difficile infection [CDI] patients with inflammatory bowel disease [IBD] has not been firmly established. Therefore, we performed a systematic review and meta-analysis to evaluate FMT treatment outcomes in patients with IBD treated for CDI.

METHODS

An electronic search of four databases was conducted until November 1, 2017. Cohort studies of FMT efficacy and safety in CDI patients with IBD were included. Pooled effect sizes were calculated with 95% confidence intervals [CI] using a random-effects model.

RESULTS

Nine cohort studies comprising a total of 346 CDI patients with IBD were included. The initial cure rate was 81% [95% CI = 76%-85%] and the overall cure rate was up to 89% [95% CI = 83%-93%], both with no significant heterogeneity. The recurrence rate was 19% [95% CI = 13%-27%] with moderate heterogeneity [Cochran's Q, p = 0.19; I2 = 33%]. There was no significant difference in the CDI cure rate after FMT in patients with and without IBD (risk ratio [RR] = 0.92; 95% CI = 0.81-1.05; Cochran's Q, p = 0.06; I2 = 53%). Subgroup analysis revealed a similar CDI treatment effects after FMT in patients with Crohn's disease and in those with ulcerative colitis [p = 0.1804]. Four studies reported adverse events of IBD flares.

CONCLUSIONS

FMT is an effective therapy for CDI in patients with IBD. Well-designed randomised controlled trials and well-conducted microbiological studies are needed to validate its efficacy and safety.

Efficacy and safety of faecal microbiota transplantation in patients with psoriatic arthritis: protocol for a 6-month, double-blind, randomised, placebo-controlled trial

INTRODUCTION

An unbalanced intestinal microbiota may mediate activation of the inflammatory pathways seen in psoriatic arthritis (PsA). A randomised, placebo-controlled trial of faecal microbiota transplantation (FMT) infused into the small intestine of patients with PsA with active peripheral disease who are non-responsive to methotrexate (MTX) treatment will be conducted. The objective is to explore clinical aspects associated with FMT performed in patients with PsA.

METHODS AND ANALYSIS

This trial is a randomised, two-centre stratified, double-blind (patient, care provider and outcome assessor), placebo-controlled, parallel-group study. Eighty patients will be included and randomised (1:1) to either placebo (saline) or FMT provided from an anonymous healthy donor. Throughout the study, both groups will continue the weekly self-administered subcutaneous MTX treatment, remaining on the preinclusion dosage (15-25 mg/week). The clinical measures of psoriasis and PsA disease activity used include the Short (2-page) Health Assessment Questionnaire, the Dermatology Quality of Life Index, the Spondyloarthritis Research Consortium of Canada Enthesitis Index, the Psoriasis Area Severity Index, a dactylitis digit count, a swollen/tender joint count (66/68), plasma C reactive protein as well as visual analogue scales for pain, fatigue and patient and physician global assessments. The primary end point is the proportion of patients who experience treatment failure during the 6-month trial period. The number of adverse events will be registered throughout the study.

ETHICS AND DISSEMINATION

This is a proof-of-concept clinical trial and will be performed in agreement with Good Clinical Practice standards. Approvals have been obtained from the local Ethics Committee (DK-S-20150080) and the Danish Data Protection Agency (15/41684). The study has commenced in May 2017. Dissemination will be through presentations at national and international conferences and through publications in international peer-reviewed journal(s).

TRIAL REGISTRATION NUMBER

NCT03058900; Pre-results.

Cost-Effectiveness of Competing Treatment Strategies for Clostridium difficile Infection: A Systematic Review

BACKGROUND Clostridium difficile infection (CDI) presents a substantial economic burden and is associated with significant morbidity. While multiple treatment strategies have been evaluated, a cost-effective management strategy remains unclear. OBJECTIVE We conducted a systematic review to assess cost-effectiveness analyses of CDI treatment and to summarize key issues for clinicians and policy makers to consider. METHODS We searched PubMed and 5 other databases from inception to August 2016. These searches were not limited by study design or language of publication. Two reviewers independently screened the literature, abstracted data, and assessed methodological quality using the Drummond and Jefferson checklist. We extracted data on study characteristics, type of CDI, treatment characteristics, and model structure and inputs. RESULTS We included 14 studies, and 13 of these were from high-income countries. More than 90% of these studies were deemed moderate-to-high or high quality. Overall, 6 studies used a decision-tree model and 7 studies used a Markov model. Cost of therapy, time horizon, treatment cure rates, and recurrence rates were common influential factors in the study results. For initial CDI, fidaxomicin was a more cost-effective therapy than metronidazole or vancomycin in 2 of 3 studies. For severe initial CDI, 2 of 3 studies found fidaxomicin to be the most cost-effective therapy. For recurrent CDI, fidaxomicin was cost-effective in 3 of 5 studies, while fecal microbiota transplantation (FMT) by colonoscopy was consistently cost-effective in 4 of 4 studies. CONCLUSIONS The cost-effectiveness of fidaxomicin compared with other pharmacologic therapies was not definitive for either initial or recurrent CDI. Despite its high cost, FMT by colonoscopy may be a cost-effective therapy for recurrent CDI. A consensus on model design and assumptions are necessary for future comparison of CDI treatment. Infect Control Hosp Epidemiol 2018;39:412-424.

Scaling Safe Access to Fecal Microbiota Transplantation: Past, Present, and Future

PURPOSE OF REVIEW

Universal stool banks (USBs) have emerged as a potential model for scaling access to fecal microbiota transplantation (FMT) for Clostridium difficile infection (CDI). In this review, we outline the historical barriers constraining access to FMT, the evidence on methods and outcomes of USBs, and potential future directions for expanding access.

RECENT FINDINGS

Key historical barriers to FMT access include regulatory uncertainty, operational complexity of sourcing screened donor material, and logistical challenges of delivering fresh treatment preparations. USBs have demonstrated that FMT can be delivered safely at scale by centralizing donor selection, material processing, and safety monitoring. More evidence is needed to optimize USB methods, including for donor screening, material processing, and novel delivery modalities. USBs have catalyzed broad access to FMT in North America and Europe. Future directions include developing evidence regarding oral preparations, harmonizing guidelines, disseminating best practice protocols, establishing long-term safety profiles, and expanding access to geographic areas of unmet need.

Risk factors for Clostridium difficile infections - an overview of the evidence base and challenges in data synthesis

Background

Recognition of a broad spectrum of disease and development of Clostridium difficile infection (CDI) and recurrent CDI (rCDI) in populations previously considered to be at low risk has renewed attention on differences in the risk profile of patients. In the absence of primary prevention for CDI and limited treatment options, it is important to achieve a deep understanding of the multiple factors that influence the risk of developing CDI and rCDI.

Methods

We conducted a review of systematic reviews and meta–analyses on risk factors for CDI and rCDI published between 1990 and October 2016.

Results

22 systematic reviews assessing risk factors for CDI (n = 19) and rCDI (n = 6) were included. Meta–analyses were conducted in 17 of the systematic reviews. Over 40 risk factors have been associated with CDI and rCDI and can be classified into three categories: pharmacological risk factors, host–related risk factors, and clinical characteristics or interventions. Most systematic reviews and meta–analyses have focused on antibiotic use (n = 8 for CDI, 3 for rCDI), proton pump inhibitors (n = 8 for CDI, 4 for rCDI), and histamine 2 receptor antagonists (n = 4 for CDI) and chronic kidney disease (n = 4 for rCDI). However, other risk factors have been assessed. We discuss the state of the evidence, methods, and challenges for data synthesis.

Conclusion

Several studies, synthesized in different systematic review, provide valuable insights into the role of different risk factors for CDI. Meta–analytic evidence of association has been reported for factors such as antibiotics, gastric acid suppressants, non–selective NSAID, and some co–morbidities. However, despite statistical significance, issues of high heterogeneity, bias and confounding remain to be addressed effectively to improve overall risk estimates. Large, prospective primary studies on risk factors for CDI with standardised case definitions and stratified analyses are required to develop more accurate and robust estimates of risk effects that can inform targeted–CDI clinical management procedures, prevention, and research.

Comparison of Different Strategies for Providing Fecal Microbiota Transplantation to Treat Patients with Recurrent Clostridium difficile Infection in Two English Hospitals: A Review

Fecal microbiota transplant (FMT) has emerged as a highly efficacious treatment for difficult cases of refractory and/or recurrent Clostridium difficile infection (CDI). There have been many well-conducted randomized controlled trials and thousands of patients reported in case series that describe success rates of approximately 90% following one or more FMT. Although the exact mechanisms of FMT have yet to be fully elucidated, replacement or restoration of a 'normal' microbiota (or at least a microbiota resembling those who have never had CDI) appears to have a positive effect on the gut dysbiosis that is thought to exist in these patients. Furthermore, despite being aesthetically unappealing, this 'ultimate probiotic' is a particularly attractive solution to a difficult problem that avoids repeated courses of antibiotics. The lack of clarity about the exact mechanism of action and the 'active ingredient' of FMT (e.g., individual or communities of bacteria, bacteriophage, or bioactive molecules such as bile acids) has hindered the ability to produce a standardized and well-characterized FMT product. There is no standard method to produce material for FMT, and there are a multitude of factors that can vary between institutions that offer this therapy. Only a few studies have directly compared clinical efficacy in groups of patients who have been treated with FMT prepared differently (e.g., fresh vs. frozen) or administered by different route (e.g., by nasojejunal tube, colonoscopy or by oral administration of encapsulated product). More of these studies should be undertaken to clarify the superiority or otherwise of these variables. This review describes the methods and protocols that two English NHS hospitals independently adopted over the same time period to provide FMT for patients with recurrent CDI. There are several fundamental differences in the methods used, including selection and testing of donors, procedures for preparation and storage of material, and route of administration. These methods are described in detail in this review highlighting differing practice. Despite these significant methodological variations, clinical outcomes in terms of cure rate appear to be remarkably similar for both FMT providers. Although both hospitals have treated only modest numbers of patients, these findings suggest that many of the described differences may not be critical factors in influencing the success of the procedure. As FMT is increasingly being proposed for a number of conditions other than CDI, harmonization of methods and techniques may be more critical to the success of FMT, and thus it will be important to standardize these as far as practically possible.

Recent insights into the tick microbiome gained through next-generation sequencing

The tick microbiome comprises communities of microorganisms, including viruses, bacteria and eukaryotes, and is being elucidated through modern molecular techniques. The advent of next-generation sequencing (NGS) technologies has enabled the genes and genomes within these microbial communities to be explored in a rapid and cost-effective manner. The advantages of using NGS to investigate microbiomes surpass the traditional non-molecular methods that are limited in their sensitivity, and conventional molecular approaches that are limited in their scalability. In recent years the number of studies using NGS to investigate the microbial diversity and composition of ticks has expanded. Here, we provide a review of NGS strategies for tick microbiome studies and discuss the recent findings from tick NGS investigations, including the bacterial diversity and composition, influential factors, and implications of the tick microbiome.

Faecal Microbiota Transplantation as Emerging Treatment in European Countries

Clostridium difficile infection (CDI) is one of the most common healthcare-associated infections in the world and is a leading cause of morbidity and mortality in hospitalized patients.Although several antibiotics effectively treat CDI, some individuals do not respond to these drugs and may be cured by transplanting stool from healthy donors. This procedure, termed Faecal Microbiota Transplantation (FMT), has demonstrated remarkable efficacy as a treatment for recurrent CDI.FMT has also been investigated in other diseases and disorders where perturbations to the gut microbiota have been theorized to play a causative role in pathogenesis and severity, such as inflammatory bowel disease (IBD). Although FMT is currently not recommended to cure IBD patients in clinical practice, several studies have recently been carried out with promising results. The aim of future research is therefore to standardize protocols and develop FMT as a therapeutic option for these patients.This review summarizes data on the use of FMT as a treatment for CDI and IBD, with special attention given to studies conducted in European countries.

Early Results of Fecal Microbial Transplantation Protocol Implementation at a Community-based University Hospital

Introduction:

Clostridium difficile (CD) is a serious and increasingly prevalent healthcare-associated infection. The pathogenesis of CD infection (CDI) involves the acquisition of CD with a concurrent disruption of the native gut flora. Antibiotics are a major risk although other contributing factors have also been identified. Clinical management combines discontinuation of the offending antibiotic, initiation of CD-specific antibiotic therapy, probiotic agent use, fecal microbiota transplantation (FMT), and surgery as the “last resort” option. The aim of this study is to review short-term clinical results following the implementation of FMT protocol (FMTP) at our community-based university hospital.

Methods:

After obtaining Institutional Review Board and Infection Control Committee approvals, we implemented an institution-wide FMTP for patients diagnosed with CDI. Prospective tracking of all patients receiving FMT between July 1, 2015, and February 1, 2017, was conducted using REDCap™ electronic data capture system. According to the FMTP, indications for FMT included (a) three or more CDI recurrences, (b) two or more hospital admissions with severe CDI, or (c) first episode of complicated CDI (CCDI). Risk factors for initial infection and for treatment failure were assessed. Patients were followed for at least 3 months to monitor for cure/failure, relapse, and side effects. Frozen 250 mL FMT samples were acquired from OpenBiome (Somerville, MA, USA). After 4 h of thawing, the liquid suspension was applied using colonoscopy, beginning with terminal ileum and proceeding distally toward mid-transverse colon. Monitored clinical parameters included disease severity (Hines VA CDI Severity Score or HVCSS), concomitant medications, number of FMT treatments, non-FMT therapies, cure rates, and mortality. Descriptive statistics were utilized to outline the study results.

Results:

A total of 35 patients (mean age 58.5 years, 69% female) were analyzed, with FMT-attributable primary cure achieved in 30/35 (86%) cases. Within this subgroup, 2/30 (6.7%) patients recurred and were subsequently cured with long-term oral vancomycin. Among five primary FMT failures (14% total sample), 3 (60%) achieved medical cure with long-term oral vancomycin therapy and 2 (40%) required colectomy. For the seven patients who either failed FMT or recurred, long-term vancomycin therapy was curative in all but two cases. For patients with severe CDI (HVCSS ≥3), primary and overall cure rates were 6/10 (60%) and 8/10 (80%), respectively. Patients with CCDI (n = 4) had higher HVCSS (4 vs. 3) and a mortality of 25%. Characteristics of patients who failed initial FMT included older age (70 vs. 57 years), female sex (80% vs. 67%), severe CDI (80% vs. 13%), and active opioid use during the initial infection (60% vs. 37%) and at the time of FMT (60% vs. 27%). The most commonly reported side effect of FMT was loose stools.

Conclusions:

This pilot study supports the efficacy and safety of FMT administration for CDI in the setting of a community-based university hospital. Following FMTP implementation, primary (86%) and overall (94%) nonsurgical cure rates were similar to those reported in other studies. The potential role of opioids as a modulator of CDI warrants further clinical investigation.

Faecal transplantation for IBD management-pitfalls and promises

BACKGROUND

Faecal microbiota transplantation (FMT) as a potential treatment for inflammatory bowel disease (IBD) is an area of active current research, having been stimulated by the remarkable efficacy of FMT in treatment of Clostridium difficile-associated colitis.

SOURCES OF DATA

This review is based on data from numerous case series on FMT in IBD since 1989 and results of four RCTs in ulcerative colitis (UC); three fully published.

AREAS OF AGREEMENT

Early signals of short to medium-term efficacy of FMT for UC are promising.

AREAS OF CONTROVERSY

Methodology, underlying mechanisms and questions regarding safety of FMT remain controversial.

GROWING POINTS

Many trials of FMT in adults and children are currently recruiting.

AREAS TIMELY FOR DEVELOPING RESEARCH

Future trials of FMT will likely revisit Crohn's disease and patients undergoing pouch surgery. Advances in microbial culture complementing genetic sequencing and investigations into the virome and mycobiome in IBD will be of great future interest.

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.

Clostridium difficile infection in the elderly: an update on management

The burden of Clostridium difficile infection (CDI) is profound and growing. CDI now represents a common cause of health care–associated diarrhea, and is associated with significant morbidity, mortality, and health care costs. CDI disproportionally affects the elderly, possibly explained by the following risk factors: age-related impairment of the immune system, increasing antibiotic utilization, and frequent health care exposure. In the USA, recent epidemiological studies estimate that two out of every three health care–associated CDIs occur in patients 65 years or older. Additionally, the elderly are at higher risk for recurrent CDI. Existing therapeutic options include metronidazole, oral vancomycin, and fidaxomicin. Choice of agent depends on disease severity, history of recurrence, and, increasingly, the drug cost. Bezlotoxumab, a recently approved monoclonal antibody targeting C. difficile toxin B, offers an exciting advancement into immunologic therapies. Similarly, fecal microbiota transplantation is gaining popularity as an effective option mainly for recurrent CDI. The challenge of decreasing CDI burden in the elderly involves adopting preventative strategies, optimizing initial treatment, and decreasing the risk of recurrence. Expanded strategies are certainly needed to improve outcomes in this high-risk population. This review considers available data from prospective and retrospective studies as well as case reports to illustrate the merits and gaps in care related to the management of CDI in the elderly.

Modulation of the gut microbiota: a focus on treatments for irritable bowel syndrome

Irritable bowel syndrome (IBS), which is characterized by recurrent abdominal pain and disordered bowel habits, is one of the most common functional bowel disorders. IBS is a substantial burden on both patient health-related quality of life and healthcare costs. Several pathophysiologic mechanisms have been postulated for the occurrence of IBS, including altered gastrointestinal motility, visceral hypersensitivity, changes in gut permeability, immune activation, gut-brain dysregulation, central nervous system dysfunction, and changes in the gut microbiota. Of note, both qualitative and quantitative differences have been observed in the gut microbiota of a population with IBS versus a healthy population. Because of the substantial interest in the gut microbiota and its role as a therapeutic target in IBS, this article provides an overview of specific interventions with the potential to modulate the gut microbiota in IBS, including elimination diets, prebiotics, probiotics, synbiotics, and nonsystemic antibiotics. Although probiotics and synbiotics are generally well tolerated, differences in the composition and concentration of different bacterial species and inclusion or exclusion of prebiotic components varies widely across studies and has prevented strong recommendations on their use in IBS. For nonsystemic antibiotics, rifaximin is indicated in the United States for the treatment of IBS with diarrhea in adults and has been shown to be efficacious and well tolerated in well-designed clinical trials. Overall, more consistent evidence is needed regarding the efficacy and safety of elimination diets, prebiotics, probiotics, and synbiotics for the treatment of patients with IBS. Furthermore, additional well-designed studies are needed that examine alterations in the gut microbiota that occur with these interventions and their potential associations with clinical symptoms of IBS.

Fecal Microbiota Therapy With a Focus on Clostridium difficile Infection

There has been a paradigm shift in our view of bacteria away from their role as just pathogens. We now have a deepening appreciation of their critical influences in our health maintenance, including energy harvest, metabolism, intestinal development, cell proliferation, nervous system and immune function, as well as their role to protect against intestinal and other infections. A perturbed intestinal microbiome has been associated with an increasing number of gastrointestinal and nongastrointestinal diseases but particularly with Clostridium difficile infection (CDI). Although such association does not imply causation, it has been shown that fecal microbiota transplantation (FMT) can correct the dysbiosis that characterizes chronic and recurring CDI and that FMT can effect a seemingly safe and rapidly effective cure for most patients with CDI so treated. FMT has been used to treat a wide range of other diseases, although conclusions about efficacy in any disease other than CDI must await appropriate well-designed trials. More work needs to be conducted with FMT, especially to evaluate and ensure its long-term safety. Future studies are likely to narrow the spectrum of organisms that needs to be given to patients to cure CDI, and perhaps other diseases, and to elucidate the mechanisms whereby such therapeutic benefit occurs. FMT is but the first step in this journey.

Systematic review with meta-analysis: the efficacy of faecal microbiota transplantation for the treatment of recurrent and refractory Clostridium difficile infection

BACKGROUND

Clostridium difficile infection (CDI) is the commonest nosocomial cause of diarrhoea. Faecal microbiota transplantation (FMT) is an approved treatment for recurrent or refractory CDI but there is uncertainty about its use.

AIM

To evaluate the efficacy of FMT in treating recurrent and refractory CDI and investigate outcomes from modes of delivery and preparation.

METHODS

A systematic review and meta-analysis was performed. MEDLINE, EMBASE, CINAHL, Cochrane Library, trial registers and conference proceedings were searched. Studies on FMT in recurrent and refractory CDI were included. The primary outcome was clinical resolution with subgroup analyses of modes of delivery and preparation. Random effects meta-analyses were used to combine data.

RESULTS

Thirty seven studies were included; seven randomised controlled trials and 30 case series. FMT was more effective than vancomycin (RR: 0.23 95%CI 0.07-0.80) in resolving recurrent and refractory CDI. Clinical resolution across all studies was 92% (95%CI 89%-94%). A significant difference was observed between lower GI and upper GI delivery of FMT 95% (95%CI 92%-97%) vs 88% (95%CI 82%-94%) respectively (P=.02). There was no difference between fresh and frozen FMT 92% (95%CI 89%-95%) vs 93% (95%CI 87%-97%) respectively (P=.84). Administering consecutive courses of FMT following failure of first FMT resulted in an incremental effect. Donor screening was consistent but variability existed in recipient preparation and volume of FMT. Serious adverse events were uncommon.

CONCLUSION

Faecal microbiota transplantation is an effective treatment for recurrent and refractory Clostridium difficile infection, independent of preparation and route of delivery.

Beyond gut feelings: how the gut microbiota regulates blood pressure

Hypertension is the leading risk factor for heart disease and stroke, and is estimated to cause 9.4 million deaths globally every year. The pathogenesis of hypertension is complex, but lifestyle factors such as diet are important contributors to the disease. High dietary intake of fruit and vegetables is associated with reduced blood pressure and lower cardiovascular mortality. A critical relationship between dietary intake and the composition of the gut microbiota has been described in the literature, and a growing body of evidence supports the role of the gut microbiota in the regulation of blood pressure. In this Review, we describe the mechanisms by which the gut microbiota and its metabolites, including short-chain fatty acids, trimethylamine N-oxide, and lipopolysaccharides, act on downstream cellular targets to prevent or contribute to the pathogenesis of hypertension. These effects have a direct influence on tissues such as the kidney, the endothelium, and the heart. Finally, we consider the role of the gut microbiota in resistant hypertension, the possible intergenerational effect of the gut microbiota on blood pressure regulation, and the promising therapeutic potential of gut microbiota modification to improve health and prevent disease.

The microbiota-gut-brain axis in obesity

Changes in microbial diversity and composition are increasingly associated with several disease states including obesity and behavioural disorders. Obesity-associated microbiota alter host energy harvesting, insulin resistance, inflammation, and fat deposition. Additionally, intestinal microbiota can regulate metabolism, adiposity, homoeostasis, and energy balance as well as central appetite and food reward signalling, which together have crucial roles in obesity. Moreover, some strains of bacteria and their metabolites might target the brain directly via vagal stimulation or indirectly through immune-neuroendocrine mechanisms. Therefore, the gut microbiota is becoming a target for new anti-obesity therapies. Further investigations are needed to elucidate the intricate gut-microbiota-host relationship and the potential of gut-microbiota-targeted strategies, such as dietary interventions and faecal microbiota transplantation, as promising metabolic therapies that help patients to maintain a healthy weight throughout life.

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.

The Present Status of Fecal Microbiota Transplantation and Its Value in the Elderly

OPINION STATEMENT

PURPOSE OF REVIEW: This article will review current literature describing fecal microbiota transplantation (FMT) in the treatment of various diseases, and its potential role in elderly patients (age ≥ 65 years).

RECENT FINDINGS

Research on FMT has blossomed in the last decade and its pivotal role in the treatment of recurrent Clostridium difficile infection (CDI) has been recognized by the American College of Gastroenterology in the latest guidelines. There is also emerging evidence that FMT may be beneficial in the treatment of severe and/or complicated CDI refractory to medical therapy, resulting in decreased rates of colectomy and mortality. In the elderly, CDI is associated with markedly higher rates of mortality and colectomy; outcomes are even worse when patients have underlying inflammatory bowel disease (IBD). While the majority of patients who receive FMT for CDI are older, only a handful of studies focused specifically on FMT treatment outcomes and safety in this age group. Current data corroborate the efficacy and safety profile of FMT, while also supporting its use for recurrent, severe, and/or complicated CDI in the elderly population. FMT is recommended for the treatment of recurrent, severe, and/or complicated CDI in patients older than 65 years of age. It may be prudent to offer FMT earlier in the disease course, possibly after just the second recurrence and for the first episode of severe CDI to avert complications including colectomy and end-organ failure that elderly patients are more prone to developing.

The Human Microbiome and the Missing Heritability Problem

The "missing heritability" problem states that genetic variants in Genome-Wide Association Studies (GWAS) cannot completely explain the heritability of complex traits. Traditionally, the heritability of a phenotype is measured through familial studies using twins, siblings and other close relatives, making assumptions on the genetic similarities between them. When this heritability is compared to the one obtained through GWAS for the same traits, a substantial gap between both measurements arise with genome wide studies reporting significantly smaller values. Several mechanisms for this "missing heritability" have been proposed, such as epigenetics, epistasis, and sequencing depth. However, none of them are able to fully account for this gap in heritability. In this paper we provide evidence that suggests that in order for the phenotypic heritability of human traits to be broadly understood and accounted for, the compositional and functional diversity of the human microbiome must be taken into account. This hypothesis is based on several observations: (A) The composition of the human microbiome is associated with many important traits, including obesity, cancer, and neurological disorders. (B) Our microbiome encodes a second genome with nearly a 100 times more genes than the human genome, and this second genome may act as a rich source of genetic variation and phenotypic plasticity. (C) Human genotypes interact with the composition and structure of our microbiome, but cannot by themselves explain microbial variation. (D) Microbial genetic composition can be strongly influenced by the host's behavior, its environment or by vertical and horizontal transmissions from other hosts. Therefore, genetic similarities assumed in familial studies may cause overestimations of heritability values. We also propose a method that allows the compositional and functional diversity of our microbiome to be incorporated to genome wide association studies.

Gut microbiota: A player in aging and a target for anti-aging intervention

Aging-associated alterations in composition, diversity and functional features of intestinal microbiota are well-described in the modern literature. They are suggested to be caused by an age-related decline in immune system functioning (immunosenescence) and a low-grade chronic inflammation (inflammaging), which accompany many aging-associated pathologies. The microbiota-targeted dietary and probiotic interventions have been shown to favorably affect the host health and aging by an enhancement of antioxidant activity, improving immune homeostasis, suppression of chronic inflammation, regulation of fat deposition and metabolism and prevention of insulin resistance. Recently, a high effectiveness and safety of novel therapeutic application such as fecal microbiota transplantation in the prevention and treatment of age-related pathological conditions including atherosclerosis, type 2 diabetes and Parkinson's disease has been demonstrated. In this review, recent research findings are summarized on the role of gut micribiota in aging processes with emphasis on therapeutic potential of microbiome-targeted interventions in anti-aging medicine.

Changes in Composition of the Gut Bacterial Microbiome after Fecal Microbiota Transplantation for Recurrent Clostridium difficile Infection in a Pediatric Heart Transplant Patient

The microbiome is increasingly recognized as an important influence on human health and many of the comorbidities that affect patients after solid organ transplantation (SOT) have been shown to involve changes in gut bacterial populations. Thus, microbiome changes in an individual patient may have important health implications after SOT but this area remains understudied. We describe changes in the composition of the fecal microbiome from a pediatric heart transplant recipient before and >2.5 years after he underwent repeated fecal microbiota transplantation (FMT) for recurrent Clostridium difficile infection (CDI). With both documented episodes of CDI, there was marked loss of bacterial diversity with overgrowth of Proteobacteria (>98.9% of phyla identified) associated with symptomatic colitis that was corrected after FMT. We hypothesize that a second CDI occurring after FMT was related to incomplete restoration of normal bowel flora post-FMT with relative deficiencies of the phyla Firmicutes and Bacteroidetes and the families Lachnospiraceae and Ruminococcaceae. Following the second FMT, there was a gradual shift in gut bacterial composition coincident with the recipient developing lymphonodular hyperplasia of the colon and painless hematochezia that resolved with discontinuation of mycophenolate mofetil (MMF). This case documents dynamic changes in the bacterial microbiome after FMT and suggests that MMF may influence the gut microbiome with consequences for the patient.

Randomised clinical trial: faecal microbiota transplantation for recurrent Clostridum difficile infection - fresh, or frozen, or lyophilised microbiota from a small pool of healthy donors delivered by colonoscopy

BACKGROUND

Faecal microbiota transplantation (FMT) has become routine in managing recurrent C. difficile infection (CDI) refractory to antibiotics.

AIM

To compare clinical response and improvements in colonic microbiota diversity in subjects with recurrent CDI using different donor product.

METHODS

Seventy-two subjects with ≥3 bouts of CDI were randomised in a double-blind study to receive fresh, frozen or lyophilised FMT product via colonoscopy from 50 g of stool per treatment from eight healthy donors. Recipients provided stools pre- and 7, 14 and 30 days post-FMT for C. difficile toxin and, in a subset, microbiome composition by 16S rRNA gene profiling.

RESULTS

Overall resolution of CDI was 87% during 2 months of follow-up after FMT. Stool samples before FMT had significantly decreased bacterial diversity with a high proportion of Proteobacteria compared to donors. Cure rates were highest for the group receiving fresh product seen in 25/25 (100%), lowest for the lyophilised product 16/23 (78%; P = 0.022 vs. fresh and 0.255 vs. frozen) and intermediate for frozen product 20/24 (P = 0.233 vs. fresh). Microbial diversity was reconstituted by day 7 in the subjects receiving fresh or frozen product. Improvement in diversity was seen by day 7 in those randomised to lyophilised material with reconstitution by 30 days.

CONCLUSIONS

Comparative efficacy in faecal microbiota transplantation was observed in subjects receiving fresh or frozen faecal product from the same donors. The lyophilised product had a slightly lowered efficacy compared with fresh product, but it resembled other treatments in microbial restoration 1 month after faecal microbiota transplantation.