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

How to adapt an intestinal microbiota transplantation programme to reduce the risk of invasive multidrug-resistant infection

BACKGROUND

Vulnerable patients with intestinal colonization of multidrug-resistant organisms (MDROs) are recognized to be at increased risk of invasive MDRO-driven infection. Intestinal microbiota transplantation (IMT, also called faecal microbiota transplant) is the transfer of healthy screened donor stool to an affected recipient, and recent interest has focused on its impact on the reduction of invasive MDRO infection.

OBJECTIVES

To describe how to establish a clinical IMT pathway for patients at risk of MDRO invasive infection, with special considerations for optimizing administration and assessment of endpoints.

SOURCES

Expert guidelines and peer-reviewed clinical studies are encompassed and discussed.

CONTENT

IMT is offered to patients with MDROs detected on rectal or stool screening and either at risk of MDRO invasive infection due to altered immune status or those with recurrent MDRO-mediated invasive disease and considered at risk of further disease. Donor screening should include pathogens with theoretical or demonstrated risk of transmission (including MDROs themselves and SARS-CoV-2) and take into consideration the relative immunosuppressed state of potential recipients. Delivery of IMT is timed for when the patient is free from active infection, but no additional antibiotics are indicated. If administered when future immunosuppression is to take place, IMT is aligned at least 2 weeks beforehand to ensure sufficient time for engraftment. Patients are followed up in terms of adverse effects from IMT and clinicians are advised to discuss with the IMT multidisciplinary team on choice of antibiotics if needed to take into consideration the impact upon the intestinal microbiome. Prevention of invasive disease is the primary measure of success, rather than using intestinal decolonization as a binary outcome. Repeat IMT is considered case by case.

IMPLICATIONS

Future research areas should include randomized studies that consider clinical outcomes and cost-effectiveness, and better understanding of mechanisms to identify markers of treatment success and functional microbiome components that could be used therapeutically.

Frontiers in antibiotic alternatives for Clostridioides difficile infection

Clostridioides difficile (C. difficile) is a gram-positive, anaerobic spore-forming bacterium and a major cause of antibiotic-associated diarrhea. Humans are naturally resistant to C. difficile infection (CDI) owing to the protection provided by healthy gut microbiota. When the gut microbiota is disturbed, C. difficile can colonize, produce toxins, and manifest clinical symptoms, ranging from asymptomatic diarrhea and colitis to death. Despite the steady-if not rising-prevalence of CDI, it will certainly become more problematic in a world of antibiotic overuse and the post-antibiotic era. C. difficile is naturally resistant to most of the currently used antibiotics as it uses multiple resistance mechanisms. Therefore, current CDI treatment regimens are extremely limited to only a few antibiotics, which include vancomycin, fidaxomicin, and metronidazole. Therefore, one of the main challenges experienced by the scientific community is the development of alternative approaches to control and treat CDI. In this Frontier article, we collectively summarize recent advances in alternative treatment approaches for CDI. Over the past few years, several studies have reported on natural product-derived compounds, drug repurposing, high-throughput library screening, phage therapy, and fecal microbiota transplantation. We also include an update on vaccine development, pre- and pro-biotics for CDI, and toxin antidote approaches. These measures tackle CDI at every stage of disease pathology via multiple mechanisms. We also discuss the gaps and concerns in these developments. The next epidemic of CDI is not a matter of if but a matter of when. Therefore, being well-equipped with a collection of alternative therapeutics is necessary and should be prioritized.

The Fecal Microbiota Transplantation: A Remarkable Clinical Therapy for Slow Transit Constipation in Future

Slow transit constipation is a common condition that would be difficult to treat in clinical practice with a widespread incidence in the population. Pharmacotherapy and surgery are common treatment modalities. However, the clinical effect is limited, and patients still suffer from it. As the researchers strived in this field for decades, the profound relationship between slow transit constipation and fecal microbiota transplantation has comprehensively been sustained. It is very pivotal to maintain intestinal homeostasis, the structure function and metabolic function of symbiotic bacteria, which can inhibit the engraftment of intestinal pathogens. This mini review explains the treatment effects and possible mechanisms of the fecal microbiota transplantation in treating slow transit constipation. Simultaneously, it is found that there is significant improvement in the disease by adjusting the intestinal microbes like fecal microbiota transplantation. Fecal microbiota transplantation has efficient therapeutic effects in slow transit constipation compared with traditional therapies.

Blockade of T helper 17 cell function ameliorates recurrent Clostridioides difficile infection in mice

Clostridioides difficile infection (CDI) is a common infection of the gastrointestinal tract. Typically, 20%-30% of CDI patients experience recurrent C.difficile infection (RCDI). Although the role of Th17 in infectious and inflammatory diseases including CDI has gained attention, reports on the correlation between Th17 and RCDI are scarce. In this study, CDI and RCDI mice models were challenged with C. difficile. Serum lactic acid dehydrogenase, inflammatory factor levels, reverse transcriptase-polymerase chain reaction, western blot analysis, hematoxylin and eosin staining, immunohistochemistry, flow cytometry analysis, and enzyme-linked immunosorbent assay were performed on the CDI, RCDI, and control group mice. The results showed more serious clinical manifestations in the RCDI group compared with those in the CDI group. More severe gut barrier disruption and higher degree of microbiota translocation were observed in the RCDI group compared with those in the CDI group. Moreover, extremely severe apoptosis was observed in HCT-116 cells incubated with the serum from RCDI mice model. In addition, higher levels of Th17 and IL-17 were detected in the blood or serum from the RCDI mouse model. Treatment with RORγt small molecule inhibitor SR1001 increased the expression of occludin, decreased the apoptotic rate of HCT-116 cells, and decreased the concentrations of Th17 and IL-17. Concisely, Th17 and IL-17 are potential indicators of RCDI and may serve as therapeutic targets for RCDI treatment. This study lays the foundation for future research on RCDI diagnosis and treatment.

High prevalence of extended-spectrum beta-lactamase organisms and the COVID-19 pandemic impact on donor recruitment for fecal microbiota transplantation in Hong Kong

Background

With increasing number of clinical trials relating to fecal microbiota transplantation (FMT), it is crucial to identify and recruit long‐term, healthy, and regular fecal donors.

Objective

We aimed to report the outcomes of screening and recruitment of fecal donors for FMT.

Methods

Potential donors were recruited via advertisement through internal mass emails at a university. They were required to undergo a pre‐screening telephone interview, a detailed questionnaire, followed by blood and stool investigations.

Results

From January 2017 to December 2020, 119 potential donors were assessed with 75 failed pre‐screening. Reasons for failure included: inability to come back for regular and long‐term donation (n = 19), high body mass index (n = 17), underlying chronic illness or on long‐term medications (n = 11), being healthcare professionals (n = 10), use of antibiotics within 3 months (n = 5) and others (n = 13). Forty‐four donors completed questionnaires and 11 did not fulfill the clinical criteria. Of the remaining 33 potential donors who had stool and blood tests, 21 failed stool investigations (19 extended‐spectrum beta‐lactamase [ESBL] organisms, one Clostridioides difficile, one C. difficile plus Methicillin Resistant Staphylococcus aureus), one failed blood tests (high serum alkaline phosphatase level), one required long‐term medication and nine withdrew consent and/or lost to follow‐up. In total, only one out of 119 (0.8%) potential donors was successfully recruited as a regular donor.

Conclusion

There was a high failure rate in donor screening for FMT. Main reasons for screening failure included high prevalence of positive ESBL organisms in stool and failed commitment to regular stool donation.

Fecal Microbiota Transplantation Modulates the Gut Flora Favoring Patients With Functional Constipation

Intestinal dysmotility is common in many diseases and is correlated with gut microbiota dysbiosis and systemic inflammation. Functional constipation (FC) is the most typical manifestation of intestinal hypomotility and reduces patients' quality of life. Some studies have reported that fecal micriobiota transplantation (FMT) may be an effective and safe therapy for FC as it corrects intestinal dysbiosis. This study was conducted to evaluate how FMT remodels the gut microbiome and to determine a possible correlation between certain microbes and clinical symptoms in constipated individuals. Data were retrospectively collected on 18 patients who underwent FMT between January 1, 2019 and June 30, 2020. The fecal bacterial genome was detected by sequencing the V3-V4 hypervariable regions of the 16S rDNA gene. Fecal short chain fatty acids (SCFAs) were detected by gas chromatography-mass spectrometry, and serum inflammatory factor concentrations were detected via enzyme-linked immunosorbent assay. Comparing the changes in fecal microbiome compositions before and after FMT revealed a significant augmentation in the alpha diversity and increased abundances of some flora such as Clostridiales, Fusicatenibacter, and Paraprevotella. This was consistent with the patients experiencing relief from their clinical symptoms. Abundances of other flora, including Lachnoanaerobaculum, were decreased, which might correlate with the severity of patients' constipation. Although no differences were found in SCFA production, the butyric acid concentration was correlated with both bacterial alterations and clinical symptoms. Serum IL-8 levels were significantly lower after FMT than at baseline, but IL-4, IL-6, IL-10, and IL-12p70 levels were not noticeably changed. This study showed how FMT regulates the intestinal microenvironment and affects systemic inflammation in constipated patients, providing direction for further research on the mechanisms of FMT. It also revealed potential microbial targets for precise intervention, which may bring new breakthroughs in treating constipation.

Enteral feeding and the microbiome in critically ill children: a narrative review

OBJECTIVE

This narrative review summarizes our current knowledge on the interplay between enteral nutrition (EN) and gut microbiota in critically ill children, using examples from two commonly encountered diagnoses in the pediatric intensive care unit (PICU): severe sepsis and acute respiratory distress syndrome (ARDS). This review will also highlight potential areas of therapeutic interventions that should be explored in future studies.

BACKGROUND

Critically ill children display extreme dysbiosis in their gut microbiome. Factors within the PICU that are often associated with dysbiosis include the use of broad-spectrum antibiotics, proton-pump inhibitors (PPIs), intravenous morphine, and fasting. Dysbiosis can potentially lead to adverse clinical outcomes (e.g., nosocomial infection, and prolonged hospitalization). EN may modulate dysbiosis. The gut microbiota is involved in the breaking down of macronutrients, mainly carbohydrates and proteins. Fermentation of undigestible carbohydrate (e.g., inulin and oligosaccharides), and amino acids by large intestine microbiota produces short chain fatty acids (SCFAs). SCFAs serve as the main fuel source for enterocytes and help to maintain healthy gut lining. Changes to selected components of macronutrients can result in alterations in gut microbiome and have potentially beneficial effects in patients in the PICU.

METHODS

A comprehensive search of the MEDLINE, Cochrane Library and Google Scholar databases was conducted using appropriate MESH terms and keywords. In this narrative review, we provide a summary of current knowledge on effect of EN on gut microbiota in pediatric studies, but also describes animal- and lab-based, as well as adult studies where relevant.

CONCLUSIONS

The gut microbiome can be altered by dietary modifications and common PICU practices and treatment. Although there are strong associations in restoring eubiosis and improvement in clinical outcomes, proving causality remains challenging. Further microbiome research is needed to provide mechanistic insights into the impact of the ever changing gut microbiome. In the future, new microbiota targeted therapies could potentially be the treatment of challenging PICU conditions and restore homeostasis in these children.

Fecal Microbiota Transplant Mitigates Adverse Outcomes Seen in Patients Colonized With Multidrug-Resistant Organisms Undergoing Allogeneic Hematopoietic Cell Transplantation

The gut microbiome can be adversely affected by chemotherapy and antibiotics prior to hematopoietic cell transplantation (HCT). This affects graft success and increases susceptibility to multidrug-resistant organism (MDRO) colonization and infection. We performed an initial retrospective analysis of our use of fecal microbiota transplantation (FMT) from healthy donors as therapy for MDRO-colonized patients with hematological malignancy. FMT was performed on eight MDRO-colonized patients pre-HCT (FMT-MDRO group), and outcomes compared with 11 MDRO colonized HCT patients from the same period. At 12 months, survival was significantly higher in the FMT-MDRO group (70% versus 36% p = 0.044). Post-HCT, fewer FMT-MDRO patients required intensive care (0% versus 46%, P = 0.045) or experienced fever (0.29 versus 0.11 days, P = 0.027). Intestinal MDRO decolonization occurred in 25% of FMT-MDRO patients versus 11% non-FMT MDRO patients. Despite the significant differences and statistically comparable patient/transplant characteristics, as the sample size was small, a matched-pair analysis between both groups to non-MDRO colonized control cohorts (2:1 matching) was performed. At 12 months, the MDRO group who did not have an FMT had significantly lower survival (36.4% versus 61.9% respectively, p=0.012), and higher non relapse mortality (NRM; 60.2% versus 16.7% respectively, p=0.009) than their paired non-MDRO-colonized cohort. Conversely, there was no difference in survival (70% versus 43.4%, p=0.14) or NRM (12.5% versus 31.2% respectively, p=0.24) between the FMT-MDRO group and their paired non-MDRO cohort. Collectively, these data suggest that negative clinical outcomes, including mortality associated with MDRO colonization, may be ameliorated by pre-HCT FMT, even in the absence of intestinal MDRO decolonization. Further work is needed to explore this observed benefit.

The Risk of Clostridioides difficile Infection in Cirrhotic Patients Receiving Norfloxacin for Secondary Prophylaxis of Spontaneous Bacterial Peritonitis-A Real Life Cohort

Background and Objectives: Spontaneous bacterial peritonitis (SBP) is a life-threatening complication of liver cirrhosis. Antibiotic prophylaxis is effective but can lead to an increased incidence of Clostridioides difficile infection (CDI). The aim of this study was to evaluate the incidence of CDI and the risk factors in cirrhotic patients with a previous episode of SBP receiving norfloxacin as secondary prophylaxis. Materials and Methods: We performed a prospective, cohort study including patients with liver cirrhosis and SBP, successfully treated over a 2-year period in a tertiary university hospital. All the patients received secondary prophylaxis for SBP with norfloxacin 400 mg/day. Results: There were 122 patients with liver cirrhosis and SBP included (mean age 57.5 ± 10.8 years, 65.5% males). Alcoholic cirrhosis was the major etiology accounting for 63.1% of cases. The mean MELD score was 19.7 ± 6.1. Twenty-three (18.8%) of all patients developed CDI during follow-up, corresponding to an incidence of 24.8 cases per 10,000 person-years. The multivariate Cox regression analysis demonstrated that alcoholic LC etiology (HR 1.40, 95% CI 1.104-2.441, p = 0.029) and Child-Pugh C class (HR 2.50, 95% CI 1.257-3.850, p = 0.034) were independent risk factors for CDI development during norfloxacin secondary prophylaxis. The development of CDI did not influence the mortality rates in cirrhotic patients with SBP receiving norfloxacin. Conclusions: Cirrhotic patients with SBP and Child-Pugh C class and alcoholic liver cirrhosis had a higher risk of developing Clostridioides difficile infection during norfloxacin secondary prophylaxis. In patients with alcoholic Child-Pugh C class liver cirrhosis, alternative prophylaxis should be evaluated as SBP secondary prophylaxis.

Novel approaches to intervene gut microbiota in the treatment of chronic liver diseases

Recent investigations of gut microbiota have contributed to understanding of the critical role of microbial community in pathophysiology. Dysbiosis not only causes disturbance directly to the gastrointestinal tract but also affects the liver through gut-liver axis. Various types of dysbiosis have been documented in alcoholic liver disease (ALD), nonalcoholic fatty liver disease, autoimmune hepatitis (AIH), primary sclerosing cholangitis, and may be crucial for the initiation, progression, or deterioration to end-stage liver disease. A few microbial species have been identified as the causal factors leading to these chronic illnesses that either do not have clear etiologies or lack effective treatment. Notably, cytolysin-producing Enterococcus faecalis, Klebsiella pneumoniae and Enterococcus gallinarum were defined for ALD, NASH, and AIH, respectively. These groundbreaking discoveries drive a rapid development in innovative therapeutics, such as fecal microbial transplantation and implementation of specific bacteriophages in addition to prebiotics, probiotics, or synbiotics for intervention of dysbiosis. Although most emerging interventions are in preclinical development or early clinical trials, a better delineation of specific dysbiosis in these disorders at metabolic, immunogenic, or molecular levels in establishing particular causal effects aids in modulating or correcting the microbial community which is the part of daily life for human being.

Danish national guideline for the treatment of Clostridioides difficile infection and use of faecal microbiota transplantation (FMT)

Aim: This Danish national guideline describes the treatment of adult patients with Clostridioides (formerly Clostridium) difficile (CD) infection and the use of faecal microbiota transplantation (FMT). It suggests minimum standard for implementing an FMT service.Method: Four scientific societies appointed members for a working group which conducted a systematic literature review and agreed on the text and recommendations. All clinical recommendations were evalluated for evidence level and grade of recommendation.Results: In CD infection, the use of marketed and experimental antibiotics as well as microbiota-based therapies including FMT are described. An algorithm for evaluating treatment effect is suggested. The organisation of FMT, donor recruitment and screening, laboratory preparation, clinical application and follow-up are described.Conclusion: Updated evidence for the treatment of CD infection and the use of FMT is provided.

Systematic review with meta-analysis: encapsulated faecal microbiota transplantation - evidence for clinical efficacy

BACKGROUND

Faecal microbiota transplantation (FMT) is an effective treatment of recurrent Clostridioides difficile infection (rCDI) and is being applied experimentally in other diseases. Encapsulated administration may be equivalent in efficacy to delivery through other routes.

METHODS

A systematic review was undertaken of studies using encapsulated FMT up to 26 October 2020. Data on indication, clinical outcomes, safety, treatment protocol and capsule preparation were collected and reported. Pooled rates of clinical efficacy in rCDI were calculated using random-effects meta-analysis. The impact of single variables on clinical efficacy was evaluated using univariate meta-regression.

RESULTS

A total of 35 studies reporting the treatment of 960 patients with encapsulated FMT for eight different indications met the inclusion criteria. Most studies (n = 18, 51%) and patients (n = 755, 79%) were from studies on rCDI. Cure rates after single and multiple courses of treatments with encapsulated FMT in rCDI were 85% (95% CI: 82%-88%) and 93% (95% CI: 88%-96%) respectively. The treatment outcome was not significantly affected by dose, number of delivered capsules, anaerobic/aerobic processing, single/multi-donor treatment, lyophilisation, or any other single factor in the production or delivery of encapsulated FMT. Promising but non-comparable results from the treatment of ulcerative colitis and multidrug-resistant organisms were reported.

CONCLUSIONS

Encapsulated FMT is an effective and safe treatment of rCDI, with cure rates comparable to FMT delivered through other routes. The treatment is effective despite variations in donor screening, preparation and treatment protocol. For other indications, the role of FMT capsules is still not sufficiently examined, although some studies show promising results.

PLAIN LANGUAGE SUMMARY

Transfer of faecal material through capsules in the treatment of various diseases. Evidence for clinical efficacy The bacteria and other microorganisms of the gut is different in patient with various diseases in comparison with healthy subjects.Therefore, ways to change the microorganisms of the gut in a beneficial direction has been the subject of various research projects within recent years.Faecal microbiota transplantation often referred as FMT is a method of transferring microorganisms from healthy donors to patients with various diseases and is seen as one way to change the microbial community of the gut in a beneficial direction.Faecal microbiota transplantation can be performed in different ways such as through endoscopy, enemas or capsules. The transfer through capsules is preferred by the patients and has advantages since it can be administered long-term and can be delivered to the patients in their home. In this paper, we evaluated all accessible research reporting treatment with encapsulated faecal microbiota transplantation in the treatment of various diseases. We report the following major findings:-Treatment with capsules is safe when guidelines for screening donors and testing faecal material is followed.-The treatment is highly effective in the treatment of recurrent C. difficile infection, a disease with high mortality often caused by repeated antibiotic treatments. The treatment was effective in 596 of 723 patients following one course of capsule treatment.-Faecal microbiota transplantation delivered through capsules is as effective as treatment delivered through other routes in the treatment of C. difficile infection.-The treatment is effective in the treatment of C. difficile infection across studies and countries, despite great differences in the ways the capsules were prepared and delivered.-Increasing the amount of faecal material used in the production did not affect the efficacy of the treatment.-There are promising results in the treatment of other diseases such as liver disease, inflammatory bowel disease and the treatment of multi-drug resistant bacteria.

Evaluating the knowledge, attitudes and practices of the UAE community on microbiota composition and the main factors affecting it: a cross-sectional study

OBJECTIVES

This study aims to explore the knowledge, attitudes and practices (KAP) of the population in the United Arab Emirates (UAE) regarding microbiota and the main factors affecting its composition.

DESIGN/SETTING

A cross-sectional study, using a self-administered questionnaire, was conducted from May 2018 to September 2018, recruiting participants in public venues via convenience sampling.

PARTICIPANTS

UAE residents (aged 18 years and above) who spoke either Arabic or English.

RESULTS

419 responses were completed and analysed using SPSS V.24. Only 29.3% (n=94) of the participants who defined microbiota correctly had good knowledge. There was a significant difference in knowledge among different age groups (p=0.004) and educational levels (p<0.001). Multiple linear regression (MLR) model indicated that being a university student and a healthcare professional (HCP) are the only significant predictors regarding microbiota knowledge (p=0.014 and p<0.001, respectively). Of the respondents who claimed to be aware of probiotics, only 9.1% (n=15) exhibited good knowledge. MLR model showed that being a postgraduate and an HCP are the only significant predictors for probiotics knowledge (p=0.016 and p<0.001, respectively). 42.4% (n=143) and 34.6% (n=28) of the non-medical and HCP participants, respectively, use antibiotics without a prescription. None of the respondents, with or without a medical background, demonstrated good attitudes and practices toward the use of antibiotics.

CONCLUSION

Despite the fact that the participants had a basic understanding of microbiota and probiotics, the overall knowledge was substandard. Additionally, the respondents engaged in improper practices that alter the microbiota composition, especially via antibiotics misuse. Campaigns should target the general population as well as HCPs to upheave their overall KAP.

Long-Term Follow-Up Results of Fecal Microbiota Transplantation for Irritable Bowel Syndrome: A Single-Center, Retrospective Study

Objective: This study aimed to investigate the long-term efficacy of fecal microbiota transplantation (FMT) in patients with irritable bowel syndrome (IBS).

Study Methods: In this single-center long-term follow-up study, FMT treatment was administered to patients with moderate to severe IBS (IBS severity scoring system (IBS-SSS) > 175). After 1 year of treatment, it was decided whether to repeat FMT based on IBS-SSS score (IBS-SSS > 175). Baseline characteristics before and after FMT and questionnaires were completed at 1, 3, 6, 12, 24, 36, 48, and 60 months after FMT. The study outcomes included treatment efficacy rates, change of IBS-SSS, IBS-specific quality of life and fatigue, effect on stool frequency, Bristol Stool Scale for IBS-C and IBS-D, and side effects.

Results: A total of 227 patients (47.58% IBS-C, 39.21% IBS-D, and 13.22% IBS-M) were recruited (142 females and 85 males with a mean age of 41.89 ± 13.57 years). The efficacy rates were 108 (51.92%), 147 (74.62%), 125 (74.41 %), 88 (71.54%), 78 (75.00%), 65 (73.03%), 45 (61.64%), and 37 (62.71%) at different follow-up time points. The total IBS-SSS score was 321.37 ± 73.89 before FMT, which significantly decreased after 1 month. The IBS-specific quality of life (IBS-QoL) score was 40.24 ± 11.34 before FMT, increased gradually, and was significantly higher at 3 months compared to before FMT. The total Fatigue Assessment Scale (FAS) score was 47 ± 8.64 before FMT and was significantly lower at 3 months. During follow-up, 89 (39.21%) side effects occurred that were alleviated by symptomatic treatment, and no serious adverse events were detected.

Conclusion: Based on 60 months of long-term follow-up, the safety and efficacy of FMT for IBS was established. However, as the treatment effect declines over time, periodic and repetitive FMT is required for a sustained effect.

[Efficacy and Safety of Fecal Microbiota Transplantation and Prospect of Microbe-based Therapies for Inflammatory Bowel Disease]

The use of 5-ASA, immunomodulators, biologics, and small molecule drugs are the main treatment for inflammatory bowel disease (IBD), however, fecal microbiota transplantation (FMT) is also drawing attention as a treatment to improve intestinal dysbiosis by transplantaing normal human stool into patients with IBD. FMT demonstrates relatively good effects in inducing clinical remission in IBD, but unlike Clostridium difficile infection, multiple FMT can enhance the clinical effect. There are no reports of the long-term effectiveness and safety of FMT conducted in IBD yet, therefore, well-designed, prospective studies will be needed. Gut microbiota can affect inflammatory response, intestinal barrier function, and host metabolism, so microbe-based therapies are likely to be a new treatment option for IBD. The deeper the understanding of microbe products or effectors, the more likely it is to provide personalized therapy in IBD.

A Guide to the Gut Microbiome and its Relevance to Critical Care

Although it is well-established that particular bacteria may cause gastroenteritis and other infections when present in the gut, it is only recently that scientists have made significant inroads into understanding the huge number of other bacteria and additional microbes that live within the gastrointestinal tract, referred to as the gut microbiome. In particular, it is now recognised that bacteria within the gut microbiome have a wide variety of roles in maintaining different aspects of human health, and that disturbances of these bacteria may potentially cause or contribute to a number of different medical conditions, including particular infections, certain cancers, and chronic conditions, including inflammatory bowel disease. Moreover, there is increasing awareness that these bacteria help determine how the body responds to medication, including antibiotics and chemotherapy. There has been growing interest in different approaches to alter the gut microbiome as a novel approach to medical therapy. This article provides an overview of the importance of the gut microbiome, with a particular focus on critical care.

Effects of Different Treatment of Fecal Microbiota Transplantation Techniques on Treatment of Ulcerative Colitis in Rats

Background: Ulcerative colitis (UC) is a chronic non-specific inflammatory bowel disease with abdominal pain, mucus, pus and blood in the stool as the main clinical manifestations. The pathogenesis of UC is still not completely clear, and multiple factors, such as genetic susceptibility, immune response, intestinal microecological changes and environmental factors, together lead to the onset of UC. In recent years, the role of intestinal microbiota disturbances on the pathogenesis of UC has received widespread attention. Therefore, fecal microbiota transplantation (FMT), which changes the intestinal microecological environment of UC patients by transplantation of normal fecal bacteria, has attracted increasing attention from researchers. However, there are no guidelines to recommend fresh FMT or frozen FMT in the treatment of UC, and there are few studies on this. Therefore, the purpose of this study was to explore the effects of fresh and frozen FMT methods on the treatment of experimental UC models in rats.

Results: Compared with the model control group, all FMT groups achieved better efficacy, mainly manifested as weight gain by the rats, improvements in fecal characteristics and blood stools, reduced inflammatory factors and normal bacterial microbiota. The efficacy of the frozen FMT group was better than that of the fresh FMT group in terms of behavior and colon length.

Conclusion: FMT method supplements the gut microbiota with beneficial bacteria, such as short-chain fatty acid-producing bacteria. These bacteria can regulate intestinal function, protect the mucosal barrier and reduce harmful bacteria, thus mitigating the damage to the intestinal barrier and the associated inflammatory response, resulting in UC remission. FMT is a feasible method for treating UC, with frozen FMT having a superior therapeutic effect than that of fresh FMT.

Recipient factors in faecal microbiota transplantation: one stool does not fit all

Faecal microbiota transplantation (FMT) is a promising therapy for chronic diseases associated with gut microbiota alterations. FMT cures 90% of recurrent Clostridioides difficile infections. However, in complex diseases, such as inflammatory bowel disease, irritable bowel syndrome and metabolic syndrome, its efficacy remains variable. It is accepted that donor selection and sample administration are key determinants of FMT success, yet little is known about the recipient factors that affect it. In this Perspective, we discuss the effects of recipient parameters, such as genetics, immunity, microbiota and lifestyle, on donor microbiota engraftment and clinical efficacy. Emerging evidence supports the possibility that controlling inflammation in the recipient intestine might facilitate engraftment by reducing host immune system pressure on the newly transferred microbiota. Deciphering FMT engraftment rules and developing novel therapeutic strategies are priorities to alleviate the burden of chronic diseases associated with an altered gut microbiota such as inflammatory bowel disease.

Standardized Nursing Procedures for Fecal Microbiota Transplantation via Upper Endoscopy

Fecal microbiota transplantation is an emerging treatment option that lacks a standardized nursing procedure. In our department, fecal microbiota transplantation has been undertaken to treat chronic hepatitis B and inflammatory bowel diseases since 2015. The fecal microbiota transplantation process involves various nursing measures that are critical for the successful completion of the procedures. In our center, a set of standardized nursing procedures has been established and has proved effective and operable. Standardized nursing procedures enhance the efficacy of fecal microbiota transplantation and alleviate the risk of treatment-related complications.

The role of the microbiome in gastrointestinal inflammation

The microbiome plays an important role in maintaining human health. Despite multiple factors being attributed to the shaping of the human microbiome, extrinsic factors such diet and use of medications including antibiotics appear to dominate. Mucosal surfaces, particularly in the gut, are highly adapted to be able to tolerate a large population of microorganisms whilst still being able to produce a rapid and effective immune response against infection. The intestinal microbiome is not functionally independent from the host mucosa and can, through presentation of microbe-associated molecular patterns (MAMPs) and generation of microbe-derived metabolites, fundamentally influence mucosal barrier integrity and modulate host immunity. In a healthy gut there is an abundance of beneficial bacteria that help to preserve intestinal homoeostasis, promote protective immune responses, and limit excessive inflammation. The importance of the microbiome is further highlighted during dysbiosis where a loss of this finely balanced microbial population can lead to mucosal barrier dysfunction, aberrant immune responses, and chronic inflammation that increases the risk of disease development. Improvements in our understanding of the microbiome are providing opportunities to harness members of a healthy microbiota to help reverse dysbiosis, reduce inflammation, and ultimately prevent disease progression.

How to Apply FMT More Effectively, Conveniently and Flexible - A Comparison of FMT Methods

Purpose

Metronidazol and vancomycin were long the two best options against Clostridioides (formerly Clostridium) difficile infections (CDI). Now, the cost of new drugs such as fidaxomicin directs us towards alternative treatment options, such as faecal microbiota transplant (FMT). Its effectiveness is similar to fidaxomicin. There are questions regarding its safety, but the biggest challenges are prejudice and inconvenience. Most protocols refer to FMT applied in the form of a solution. We investigated different modalities of FMT.

Methods

Instead of using nasoenteric tubes or colonoscopy, we place frozen or lyophilised stool in non-coated, size “00”, hard gelatine capsules or enterosolvent, size “0” capsules.

Results

We found that non-coated, size “00”, hard gelatine capsules are appropriate for conducting FMT. Capsules containing lyophilised supernatant with a low number of bacteria have been proven to be non-inferior to other FMT modalities. The primary cure rate in the supernatant group was 93.75%, and 66.67% in the sediment group. The overall cure rate was 82.14%. Depending on the protocol, 4–7 capsules are sufficient per patient. Capsules can be stored for up to one year at -20°C.

Conclusions

FMT is a feasible alternative to antibiotic treatments in CDI. Our method makes the process flexible and less inconvenient to patients. Long storage time allows a consistent supply of capsules, while small volume and formulation make the procedure tolerable.

Systems biology evaluation of refractory Clostridioides difficile infection including multiple failures of fecal microbiota transplantation

BACKGROUND

Fecal microbiota transplantation (FMT) aims to cure Clostridioides difficile infection (CDI) through reestablishing a healthy microbiome and restoring colonization resistance. Although often effective after one infusion, patients with continued microbiome disruptions may require multiple FMTs. In this N-of-1 study, we use a systems biology approach to evaluate CDI in a patient receiving chronic suppressive antibiotics with four failed FMTs over two years.

METHODS

Seven stool samples were obtained between 2016-18 while the patient underwent five FMTs. Stool samples were cultured for C. difficile and underwent microbial characterization and functional gene analysis using shotgun metagenomics. C. difficile isolates were characterized through ribotyping, whole genome sequencing, metabolic pathway analysis, and minimum inhibitory concentration (MIC) determinations.

RESULTS

Growing ten strains from each sample, the index and first four recurrent cultures were single strain ribotype F078-126, the fifth was a mixed culture of ribotypes F002 and F054, and the final culture was ribotype F002. One single nucleotide polymorphism (SNP) variant was identified in the RNA polymerase (RNAP) β-subunit RpoB in the final isolated F078-126 strain when compared to previous F078-126 isolates. This SNV was associated with metabolic shifts but phenotypic differences in fidaxomicin MIC were not observed. Microbiome differences were observed over time during vancomycin therapy and after failed FMTs.

CONCLUSION

This study highlights the importance of antimicrobial stewardship in patients receiving FMT. Continued antibiotics play a destructive role on a transplanted microbiome and applies selection pressure for resistance to the few antibiotics available to treat CDI.

Disease Prevention Not Decolonization: A Model for Fecal Microbiota Transplantation in Patients Colonized With Multidrug-resistant Organisms

Fecal microbiota transplantation (FMT) yields variable intestinal decolonization results for multidrug-resistant organisms (MDROs). This study showed significant reductions in antibiotic duration, bacteremia, and length of stay in 20 patients colonized/infected with MDRO receiving FMT (compared with pre-FMT history, and a matched group not receiving FMT), despite modest decolonization rates.

Dietary Strategies for Management of Metabolic Syndrome: Role of Gut Microbiota Metabolites

Metabolic syndrome (MetS) is a complex pathophysiological state with incidence similar to that of a global epidemic and represents a risk factor for the onset of chronic non-communicable degenerative diseases (NCDDs), including cardiovascular disease (CVD), type 2 diabetes mellitus, chronic kidney disease, and some types of cancer. A plethora of literature data suggest the potential role of gut microbiota in interfering with the host metabolism, thus influencing several MetS risk factors. Perturbation of the gut microbiota’s composition and activity, a condition known as dysbiosis, is involved in the etiopathogenesis of multiple chronic diseases. Recent studies have shown that some micro-organism-derived metabolites (including trimethylamine N-oxide (TMAO), lipopolysaccharide (LPS) of Gram-negative bacteria, indoxyl sulfate and p-cresol sulfate) induce subclinical inflammatory processes involved in MetS. Gut microbiota’s taxonomic species or abundance are modified by many factors, including diet, lifestyle and medications. The main purpose of this review is to highlight the correlation between different dietary strategies and changes in gut microbiota metabolites. We mainly focus on the validity/inadequacy of specific dietary patterns to reduce inflammatory processes, including leaky gut and subsequent endotoxemia. We also describe the chance of probiotic supplementation to interact with the immune system and limit negative consequences associated with MetS.

Gut bacteria formation and influencing factors

The gut microbiota plays an important role in human health. In modern life, with the improvement of living conditions, the intake of high-sugar and high-fat diets as well as the large-scale use of antibacterial drugs have an extensive impact on the gut microbiota, even leading to gut microbiota-orchestrating disorders. This review discusses the effects of various factors, including geographic location, age, diet, antibacterial drugs, psychological situation and exercise on gut bacteria, which helps us profoundly to understand the significance of gut bacteria to human health and to find effective solutions to prevent or treat related diseases.

Modern approaches to the correction of the gut microbiota

The article presents modern data on the formation, structure, functions and possibilities of correction of the gut microbiota. The gut microbiota is a collection of living organisms that inhabit the human intestine and form a complex microecological system that performs many functions. It is known that the composition and state of the gut microbiota is influenced by both environmental factors, such as diet and lifestyle, and the human body, including genetic predisposition. A violation in this system (dysbiosis) can provoke the development of a number of diseases and pathological conditions, in which the correction of the gut microbiota may be a promising therapeutic strategy. The most common methods of correcting dysbiosis are dieting, the use of pro-and prebiotics, and fecal microbiota transplantation. The diet affects the qualitative and quantitative composition and functions of the gut microbiota, the activity of its individual representatives. Probiotics are used to modulate, preserve the gut microbiota in dysbiosis, as well as to prevent its development. Fecal microbiota transplantation is performed by transferring the microbiota from a healthy donor. This method is one of the most effective ways to treat Clostridium difficile infection. This review article also presents the results of fecal microbiota transplantation in patients with inflammatory bowel disease and hepatic encephalopathy. It is shown that after transplantation, there is a rapid change in the composition of the gut microbiota, which becomes similar to the microbiota of a healthy donor. Each of these methods of correction demonstrates a different degree of influence on the gut microbiota, and their therapeutic effectiveness depends on the direct characteristics of the methods used, as well as the specific disease and requires further study.

Stool Banking for Fecal Microbiota Transplantation: Methods and Operations at a Large Stool Bank

Objectives

Fecal microbiota transplantation (FMT) is a recommended therapy for recurrent Clostridioides difficile infection and is being investigated as a potential therapy for dozens of microbiota-mediated indications. Stool banks centralize FMT donor screening and FMT material preparation with the goal of expanding access to FMT material while simultaneously improving its safety, quality, and convenience. Although there are published consensuses on donor screening guidelines, there are few reports about the implementation of those guidelines in functioning stool banks.

Methods

To help inform consensus standards with data gathered from real-world settings and, in turn, to improve patient care, here we describe the general methodology used in 2018 by OpenBiome, a large stool bank, and its outputs in that year.

Results

In 2018, the stool bank received 7,536 stool donations from 210 donors, a daily average of 20.6 donations, and processed 4,271 of those donations into FMT preparations. The median time a screened and enrolled stool donor actively donated stool was 5.8 months. The median time between the manufacture of an FMT preparation and its shipment to a hospital or physician was 8.9 months. Half of the stool bank's partner hospitals and physicians ordered an average of 0.75 or fewer FMT preparations per month.

Conclusions

Further knowledge sharing should help inform refinements of stool banking guidelines and best practices.

Microbiome-immune interactions in tuberculosis

Tuberculosis (TB) remains an infectious disease of global significance and a leading cause of death in low- and middle-income countries. Significant effort has been directed towards understanding Mycobacterium tuberculosis genomics, virulence, and pathophysiology within the framework of Koch postulates. More recently, the advent of “-omics” approaches has broadened our appreciation of how “commensal” microbes have coevolved with their host and have a central role in shaping health and susceptibility to disease. It is now clear that there is a diverse repertoire of interactions between the microbiota and host immune responses that can either sustain or disrupt homeostasis. In the context of the global efforts to combatting TB, such findings and knowledge have raised important questions: Does microbiome composition indicate or determine susceptibility or resistance to M. tuberculosis infection? Is the development of active disease or latent infection upon M. tuberculosis exposure influenced by the microbiome? Does microbiome composition influence TB therapy outcome and risk of reinfection with M. tuberculosis? Can the microbiome be actively managed to reduce risk of M. tuberculosis infection or recurrence of TB? Here, we explore these questions with a particular focus on microbiome-immune interactions that may affect TB susceptibility, manifestation and progression, the long-term implications of anti-TB therapy, as well as the potential of the host microbiome as target for clinical manipulation.

Usefulness of Fecal Calprotectin in the Management of Patients with Toxigenic Clostridioides difficile

The availability of highly sensitive molecular tests for the detection of Clostridioides difficile in feces leads to overtreatment of patients who are probably only colonized. In this prospective study, the usefulness of fecal calprotectin (fCP) is evaluated in a cohort of patients with detection of toxigenic C. difficile in feces. Patients were classified by an infectious diseases consultant blinded to fCP results into three groups-group I, presumed Clostridioides difficile infection (CDI); group II, doubtful but treated CDI; and group III, presumed C. difficile colonization or self-limited CDI not needing treatment. One hundred and thirty-four patients were included. The median fCP concentrations were 410 (138-815) μg/g in group I, 188 (57-524) μg/g in group II, and 51 (26-97) μg/g in group III (26 cases); p < 0.05 for all comparisons. In forty-five out of 134 cases (33.5%), the fCP concentrations were below 100 µg/g. In conclusion, fCP is low in most patients who do not need treatment against C. difficile, and should be investigated as a potentially useful test in the management of patients with detected toxigenic C. difficile.

Fecal Microbiota Transplantation: The Evolving Risk Landscape

Fecal microbiota transplantation (FMT) has been recommended in clinical guidelines for the treatment of recurrent Clostridioides difficile infection (CDI). However, it is considered investigational by most regulatory agencies. As the adoption of FMT has increased from a small group of CDI experts alone to more widespread use, there has been a corresponding increase in concern regarding potential risk. FMT is largely considered a safe procedure although risks described range from mild gastrointestinal symptoms to serious infection. Currently, there is variability in how "FMT" is characterized specifically regarding testing approach, which, in turn, impacts the risk profile. This has been highlighted by the rare cases of multidrug-resistant organisms, Shiga toxin-producing Escherichia and enteropathogenic E. coli, recently reported, where these organisms were not screened. These cases have prompted additional screening mandates from the US Food and Drug Administration (FDA), which has maintained its policy of enforcement discretion for the use of FMT for CDI not responding to standard therapy. Here, we examine the evolving risk landscape of FMT.

Next Generation Fecal Microbiota Transplantation

Fecal microbiota transplantation (FMT) is considered as an effective treatment for Clostridioides difficile infection. However, the precise mechanism of FMT is yet to be determined. Human stool consists of the gut microbiota, bacterial debris, and metabolic products. Of these, the intestinal microbiota is the most important factor that exerts therapeutic efficacy in FMT. Fresh donor stool, blended with normal saline, has been employed for traditional FMT. Nevertheless, stool processing is a major impediment in FMT. Frozen stool and capsule formulations have similar efficacy to that of fresh stool. In addition, several novel stool products have been identified. A stool bank that provides stool products with pre-screened donor stool has been established to help physicians and thereby facilitate FMT. Recent next-generation sequencing techniques have been key in facilitating the detailed analysis of the microbiota and gut environment of individual donors and recipients.

Faecal microbiota transplantation and the patient experience: A systematic review

AIM

To review and synthesise the literature examining the patients' experience of faecal microbiota transplantation.

BACKGROUND

Faecal microbiota transplantation is a common treatment for many conditions, including Clostridium Difficile infections. Patients' experience of treatments is an important influence on clinical decision-making and treatment adherence.

DESIGN

The PRISMA guidelines guided this systematic review. The review was registered with PROSPERO [CRD42020140446].

METHOD

A search of Cumulative Index of Nursing and Allied Health Literature, Medline and Embase was conducted for studies published in English and French up to June 2020. Risk of bias was examined using Critical Appraisal Skills Program tools, and quality appraisal was performed independently by three reviewers. Primary outcome of interest was the patient experience of faecal microbiota transplantation. Data were synthesised using a narrative approach.

RESULTS

The search identified 3316 citations, and 12 studies were included. Methodological quality of studies was moderate to low quality. Few studies have accurately explored the patients' experience of faecal microbiota transplantation: most focus on clinical outcomes or hypothetical scenarios regarding the patients' perspectives of faecal microbiota transplantation. Only one study was identified where the sole focus was the patients' experience of faecal microbiota transplantation. Patient's experience of faecal microbiota transplantation was diverse and complex with physiological and psychological components dependent on the patient's medical condition, the administration method and the efficacy.

CONCLUSION

Patients did not find faecal microbiota transplantation unappealing; however, patients equally reported the procedural experience was unpleasant. Limited results and low quality evidence suggest that further evaluation of the patient experience of faecal microbiota transplantation would be beneficial.

RELEVANCE TO CLINICAL PRACTICE

Identifying the patients' experience of faecal microbiota transplantation may inform recommendations regarding alternate treatment therapies and enable opportunities to provide quality care for patients that require faecal microbiota transplantation.

A standardised model for stool banking for faecal microbiota transplantation: a consensus report from a multidisciplinary UEG working group

BACKGROUND

Faecal microbiota transplantation is an emerging therapeutic option, particularly for the treatment of recurrent Clostridioides difficile infection. Stool banks that organise recruitment and screening of faeces donors are being embedded within the regulatory frameworks described in the European Union Tissue and Cells Directive and the technical guide to the quality and safety of tissue and cells for human application, published by the European Council.

OBJECTIVE

Several European and international consensus statements concerning faecal microbiota transplantation have been issued. While these documents provide overall guidance, we aim to provide a detailed description of all processes that relate to the collection, handling and clinical application of human donor stool in this document.

METHODS

Collaborative subgroups of experts on stool banking drafted concepts for all domains pertaining to stool banking. During a working group meeting in the United European Gastroenterology Week 2019 in Barcelona, these concepts were discussed and finalised to be included in our overall guidance document about faecal microbiota transplantation.

RESULTS

A guidance document for all domains pertaining to stool banking was created. This document includes standard operating manuals for several processes involved with stool banking, such as handling of donor material, storage and donor screening.

CONCLUSION

The implementation of faecal microbiota transplantation by stool banks in concordance with our guidance document will enable quality assurance and guarantee the availability of donor faeces preparations for patients.

Fecal Microbiota Transplantation: Is It Safe?

Fecal microbiota transplantation (FMT) is an accepted procedure for the management of recurrent Clostridioides difficile infections. FMT is generally considered safe and well-tolerated - even in high-risk patients. Most short-term risks are mild and known to be associated with delivery methods. Long-term side effects have not been established, and no signs of harm have been found to date. However, causality for several microbiome-associated diseases has to be established. Even though FMT is generally considered safe with strict donor screening, serious adverse events have been recently associated with the FMT product from the stool bank, where screening for multi-drug resistant organisms is not included in protocols. Here, we discuss the adverse events associated with FMT and safety issues.

Fecal microbiota transplantation before hematopoietic stem cell transplantation in a pediatric case of chronic diarrhea with a FOXP3 mutation

BACKGROUND

Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome is a rare disorder caused by mutation of the forkhead box protein 3 (FOXP3) gene, often leading to intractable and life-threatening diarrhea. Fecal microbiota transplantation (FMT), has been regarded in recent years as an available approach to reconstruct disrupted gut microbiome and successfully used to attenuates diarrhea induced by different underlying diseases. Therefore, FMT may have curative potential on the symptoms of enteropathy in patients with IPEX syndrome.

METHODS

Physical and laboratory examinations were performed, and clinical data were collected. FMT was administered via frozen fecal microbial solution, and the fecal microbiota composition was analyzed using 16S rDNA sequencing before and after FMT.

RESULTS

The patient was diagnosed with IPEX syndrome with a mutation detected in the FOXP3 gene, which was identified as c.767T > C (p.M256T). He presented with recurrent watery diarrhea and respiratory infections after birth and developed a significant failure to thrive. Disturbances in the gut microbiota composition and marked decreased bacterial diversity were observed to be involved in the persistent and refractory diarrhea. After receiving FMT treatment, the patient responded with remission of the diarrhea without apparent side effects. His stool output significantly decreased, corresponding to increased microbial diversity and modification of his microbiota composition. The patient finally achieved full recovery after hematopoietic stem cell transplantation (HSCT).

CONCLUSION

Our data suggest an association between the gut microbiota and clinical symptoms of patient with IPEX syndrome and demonstrate FMT as an alternative therapy for severe diarrhea unresponsive to routine therapy in these patients.

Future Directions in Reducing Gastrointestinal Disorders in Children With ASD Using Fecal Microbiota Transplantation

Research on the use of fecal microbiota transplantation (FMT) in the treatment of disorders related to digestive system ailments in children with autism spectrum disorders (ASDs) is a new attempt in a therapeutic approach. There are very little scientific evidences available on this emerging alternative method. However, it appears to be interesting not only because of its primary outcome, relieving the gastrointestinal (GI) symptoms, but also secondary therapeutic effect of alleviating autistic behavioral symptoms. FMT seems to be also promising method in the treatment of another group of pediatric patients, children with inflammatory bowel disease (IBD). The aim of this study is to discuss the potential use of FMT and modified protocols (MTT, microbiota transfer therapy) in the treatment of GI disorders in ASD children supported by reports on another disease, IBD concerning pediatric patients. Due to the few reports of the use of FMT in the treatment of children, these two patients groups were selected, although suffering from distant health conditions: neurodevelopmental disorder and gastrointestinal tract diseases, because of the the fact that they seem related in aspects of the presence of GI symptoms, disturbed intestinal microbiota, unexplained etiology of the condition and age range of patients. Although the outcomes for all are promising, this type of therapy is still an under-researched topic, studies in the group of pediatric patients are sparse, also there is a high risk of transmission of infectious and noninfectious elements during the procedure and no long-term effects on global health are known. For those reasons all obtained results should be taken with a great caution. However, in the context of future therapeutic directions for GI observed in neurodevelopmental disorders and neurodegenerative diseases, the topic seems worthy of attention.

New Insights Into the Cancer-Microbiome-Immune Axis: Decrypting a Decade of Discoveries

The past decade has witnessed groundbreaking advances in the field of microbiome research. An area where immense implications of the microbiome have been demonstrated is tumor biology. The microbiome affects tumor initiation and progression through direct effects on the tumor cells and indirectly through manipulation of the immune system. It can also determine response to cancer therapies and predict disease progression and survival. Modulation of the microbiome can be harnessed to potentiate the efficacy of immunotherapies and decrease their toxicity. In this review, we comprehensively dissect recent evidence regarding the interaction of the microbiome and anti-tumor immune machinery and outline the critical questions which need to be addressed as we further explore this dynamic colloquy.

Novel Insights Into Pathogenesis and Therapeutic Strategies of Hepatic Encephalopathy, From the Gut Microbiota Perspective

Since the 1950s, gradual changes in the gut microbiota of patients with hepatic encephalopathy have been observed. Previous research has indicated potential associations between the gut and brain, and the gut microbiota is becoming a hot topic in research on diseases of the nervous system. However, for the past few decades, studies of hepatic encephalopathy have been restricted to controlling the gut microbiota during macroscopic manipulation, such as probiotic intervention, while its clinical use remains controversial, and the cellular mechanisms underlying this condition are still poorly understood. This thesis seeks to comprehensively understand and explain the role of gut microbiota in hepatic encephalopathy as well as analyze the effects of intervention by regulating the gut microbiota. Evidence is presented that shows that dysbiosis of the gut microbiota is the primary pathological driver of hepatic encephalopathy and impacts pathologic progression via complex regulatory networks. As a result, suggestions were identified for future mechanistic research and improvements in therapeutic strategies for hepatic encephalopathy.

Crosstalk between Gut and Brain in Alzheimer's Disease: The Role of Gut Microbiota Modulation Strategies

The gut microbiota (GM) represents a diverse and dynamic population of microorganisms and about 100 trillion symbiotic microbial cells that dwell in the gastrointestinal tract. Studies suggest that the GM can influence the health of the host, and several factors can modify the GM composition, such as diet, drug intake, lifestyle, and geographical locations. Gut dysbiosis can affect brain immune homeostasis through the microbiota-gut-brain axis and can play a key role in the pathogenesis of neurodegenerative diseases, including dementia and Alzheimer's disease (AD). The relationship between gut dysbiosis and AD is still elusive, but emerging evidence suggests that it can enhance the secretion of lipopolysaccharides and amyloids that may disturb intestinal permeability and the blood-brain barrier. In addition, it can promote the hallmarks of AD, such as oxidative stress, neuroinflammation, amyloid-beta formation, insulin resistance, and ultimately the causation of neural death. Poor dietary habits and aging, along with inflammatory responses due to dysbiosis, may contribute to the pathogenesis of AD. Thus, GM modulation through diet, probiotics, or fecal microbiota transplantation could represent potential therapeutics in AD. In this review, we discuss the role of GM dysbiosis in AD and potential therapeutic strategies to modulate GM in AD.

[Fecal microbiota transplantation: donor selection criteria, storage and preparation of biomaterials (review of current recommendations)]

Fecal microbiota transplantation is a treatment method based on the introduction of donated fecal material to the recipient in order to restore the damaged composition of the intestinal microbiota. This review summarizes existing data on indications for fecal microbiota transplantation, recommendations for donor selection, processing and storage of donor biomaterial.

Breakthroughs and Bottlenecks in Microbiome Research

Over the past 15 years, the research community has witnessed unprecedented progress in microbiome research. We review this increasing knowledge and first attempts of its clinical application, and also limitations and challenges faced by the research community, in mechanistically understanding host-microbiome interactions and integrating these insights into clinical practice.

Long-term efficacy and safety of monotherapy with a single fresh fecal microbiota transplant for recurrent active ulcerative colitis: a prospective randomized pilot study

BACKGROUND

To assess the long-term safety and efficacy of monotherapy with a single fresh fecal microbiota transplant (FMT) for recurrent ulcerative colitis (UC).

RESULTS

Twenty-six eligible patients were enrolled, and 6 patients were excluded. Ultimately, 20 patients were randomized to the FMT group (n = 10) and the control group (n = 10); 80% were females (F/M = 16/4), the mean age was 48 ± 14 years, and the mean duration was 6.4 ± 8.2 years. The mean length of post-FMT follow-up was 19.1 ± 10.1 months (6-38). No statistically significant differences in baseline demographic or clinical characteristics were found between the groups. Ninety percent of patients in the FMT group and 50% of patients in the control group met the primary endpoint at week 8. The Mayo score was significantly decreased compared with that of the control group (n = 10) when reassessed at week 4 (P = 0.001) and week 8 (P = 0.019) after FMT; there was no significant difference 6 months after treatment. The median remission time was 24 months (95% CI 68.26-131.7%) in both the FMT (range 6-38 months) and control groups (range 7-35 months), with no significant difference (P = 0.895). Participants tolerated FMT treatment, and no adverse events occurred during long-term follow-up, with one treatment-related significant adverse event (EBV infection) occurring within 2 weeks after FMT. Stool microbiota composition analysis indicated improved gut microbiota diversity after FMT, with expansion of stool-donor taxa. Bacteroidetes, Firmicutes and Proteobacteria were the dominant bacterial phyla of the gut microbiota in active UC patients. The relative abundance of Bacteroidetes decreased and that of Proteobacteria increased significantly in active UC patients compared with donors, while Firmicutes showed no significant changes. A single fresh FMT could effectively reconstruct the gut microbiota composition in patients with active UC and maintain stability, with increased Bacteroidetes and decreased Proteobacteria abundance. FMT significantly reduced the relative abundance of Escherichia and increased the relative abundance of Prevotella at the genus level. Pyruvate metabolism, glyoxylate and dicarboxylate metabolism, and pantothenate and CoA biosynthesis showed significant differences after transplantation.

CONCLUSIONS

Monotherapy with a single fresh FMT is an effective and safe strategy to induce long-term remission without drugs in patients with active UC and may be an alternative induction therapy for recurrent UC or even primary UC.

Factors Related to Outcomes of Fecal Microbiota Transplantation in Patients with Clostridioides difficile Infection

Background/Aims

The aim of this study was to evaluate factors related to outcomes of fecal microbiota transplantation (FMT) in patients with Clostridioides difficile infection (CDI) and viability of frozen stock for FMT.

Methods

Clinical data of patients who had received FMT for CDI were prospectively collected. Next-generation 16S rRNA gene sequencing of bacteria was performed from donors' and recipients' stool. Colony-forming units (CFUs) of cultures from frozen stock solutions for FMT were measured at 0, 4, 8, 12, 24, 48 weeks after preparation of the solutions.

Results

In total, 25 FMT procedures were performed in 20 cases (14 fresh and 11 frozen FMT). Forty-five percent of cases involved fulminant CDI. The overall success rate was 55% after the 1st FMT and 75% after the 2nd FMT. The success rate was significantly higher in partially treated CDI than in refractory CDI (100% vs 71.4%; p=0.001). In successful cases only, the decrease in alpha-diversity in the recipient stool microbiomes was recovered after FMT to a level similar to that in donor stools. There was a significant difference in the microbiome composition in pre-FMT recipients' stool between successful and failed cases (p=0.001). The CFUs of frozen solution for FMT did not decrease for 48 weeks in both aerobic and anaerobic cultures.

Conclusions

FMT is highly effective in partially treated CDI but not in refractory CDI. The microbiome differs between failed and successful cases. Frozen stock for FMT is viable up to 48 weeks.

Washed Microbiota Transplantation Lowers Blood Pressure in Patients With Hypertension

BACKGROUND

Although transplantation of the fecal microbiota from normotensive donors has been shown to have an antihypertensive effect in hypertensive animal models, its effect on blood pressure in patients with hypertension is unclear. This study aimed to assess the effect of washed microbiota transplantation (WMT) from normotensive donors on blood pressure regulation in hypertensive patients.

METHODS

The clinical data of consecutive patients treated with washed microbiota transplantation (WMT) were collected retrospectively. The blood pressures of hypertensive patients before and after WMT were compared. The factors influencing the antihypertensive effect of WMT in hypertensive patients and fecal microbial composition of donors and hypertensive patients were also analyzed.

RESULTS

WMT exhibited an antihypertensive effect on blood pressure: the blood pressure at hospital discharge was significantly lower than that at hospital admission (change in systolic blood pressure: -5.09 ± 15.51, P = 0.009; change in diastolic blood pressure: -7.74 ± 10.42, P < 0.001). Hypertensive patients who underwent WMT via the lower gastrointestinal tract (β = -8.308, standard error = 3.856, P = 0.036) and those not taking antihypertensive drugs (β = -8.969, standard error = 4.256, P = 0.040) had a greater decrease in systolic blood pressure, and hypertensive patients not taking antihypertensive drugs also had a greater decrease in diastolic blood pressure (β = -8.637, standard error = 2.861, P = 0.004). After WMT, the Shannon Diversity Index was higher in six of eight hypertensive patients and the microbial composition of post-WMT samples tended to be closer to that of donor samples.

CONCLUSION

WMT had a blood pressure-lowering effect in hypertensive patients, especially in those who underwent WMT via the lower gastrointestinal tract and in those not taking antihypertensive drugs. Therefore, modulation of the gut microbiota by WMT may offer a novel approach for hypertension treatment.

Effects of Diet-Modulated Autologous Fecal Microbiota Transplantation on Weight Regain

BACKGROUND & AIMS

We evaluated the efficacy and safety of diet-modulated autologous fecal microbiota transplantation (aFMT) for treatment of weight regain after the weight-loss phase.

METHODS

In the DIRECT PLUS (Dietary Intervention Randomized Controlled Trial Polyphenols-Unprocessed) weight-loss trial (May 2017 through July 2018), abdominally obese or dyslipidemic participants in Israel were randomly assigned to healthy dietary guidelines, Mediterranean diet, and green-Mediterranean diet weight-loss groups. All groups received free gym membership and physical activity guidelines. Both isocaloric Mediterranean groups consumed 28 g/d walnuts (+440 mg/d polyphenols provided). The green-Mediterranean dieters also consumed green tea (3-4 cups/d) and a Wolffia globosa (Mankai strain, 100 g/d) green shake (+800 mg/d polyphenols provided). After 6 months (weight-loss phase), 90 eligible participants (mean age, 52 years; mean weight loss, 8.3 kg) provided a fecal sample that was processed into aFMT by frozen, opaque, and odorless capsules. The participants were then randomly assigned to groups that received 100 capsules containing their own fecal microbiota or placebo until month 14. The primary outcome was regain of the lost weight over the expected weight-regain phase (months 6-14). Secondary outcomes were gastrointestinal symptoms, waist circumference, glycemic status, and changes in the gut microbiome, as measured by metagenomic sequencing and 16s ribosomal RNA. We validated the results in a parallel in vivo study of mice specifically fed with Mankai compared with control chow diet.

RESULTS

Of the 90 participants in the aFMT trial, 96% ingested at least 80 of 100 oral aFMT or placebo frozen capsules during the transplantation period. No aFMT-related adverse events or symptoms were observed. For the primary outcome, although no significant differences in weight regain were observed among the participants in the different lifestyle interventions during months 6-14 (aFMT, 30.4% vs placebo, 40.6%; P = .28), aFMT significantly attenuated weight regain in the green-Mediterranean group (aFMT, 17.1%, vs placebo, 50%; P = .02), but not in the dietary guidelines (P = .57) or Mediterranean diet (P = .64) groups (P for the interaction = .03). Accordingly, aFMT attenuated waist circumference gain (aFMT, 1.89 cm vs placebo, 5.05 cm; P = .01) and insulin rebound (aFMT, -1.46 ± 3.6 μIU/mL vs placebo, 1.64 ± 4.7 μIU/mL; P = .04) in the green-Mediterranean group but not in the dietary guidelines or Mediterranean diet (P for the interaction = .04 and .03, respectively). The green-Mediterranean diet was the only intervention to induce a significant change in microbiome composition during the weight-loss phase, and to prompt preservation of weight-loss-associated specific bacteria and microbial metabolic pathways (mainly microbial sugar transport) after the aFMT. In mice, Mankai-modulated aFMT in the weight-loss phase compared with control diet aFMT, significantly prevented weight regain and resulted in better glucose tolerance during a high-fat diet-induced regain phase (all, P < .05).

CONCLUSIONS

Autologous FMT, collected during the weight-loss phase and administrated in the regain phase, might preserve weight loss and glycemic control, and is associated with specific microbiome signatures. A high-polyphenols, green plant-based or Mankai diet better optimizes the microbiome for an aFMT procedure. ClinicalTrials.gov number, NCT03020186.

Fecal microbiota transplantation in hepatic encephalopathy : a review of the current evidence and future perspectives

Hepatic encephalopathy (HE) is a leading cause of hospitalization and morbimortality in advanced cirrhosis with limited therapeutic options available. Given the paramount role of gut microbiota in HE, and the efficacy of fecal microbiota transplantation (FMT) in other diseases, this review intends to summarize the evidence supporting the safety, efficacy and future perspectives of FMT in HE. Current evidence, despite being scarce, points towards FMT being a safe, effective and tolerable procedure in HE. Some unanswered questions remain about the optimal dose, the administration route, the long term effects and the selection of the optimal donor. Future trials, some of which are already underway, will provide us additional evidence and hopefully the necessary answers.

Fighting microbial pathogens by integrating host ecosystem interactions and evolution

Successful therapies to combat microbial diseases and cancers require incorporating ecological and evolutionary principles. Drawing upon the fields of ecology and evolutionary biology, we present a systems-based approach in which host and disease-causing factors are considered as part of a complex network of interactions, analogous to studies of "classical" ecosystems. Centering this approach around empirical examples of disease treatment, we present evidence that successful therapies invariably engage multiple interactions with other components of the host ecosystem. Many of these factors interact nonlinearly to yield synergistic benefits and curative outcomes. We argue that these synergies and nonlinear feedbacks must be leveraged to improve the study of pathogenesis in situ and to develop more effective therapies. An eco-evolutionary systems perspective has surprising and important consequences, and we use it to articulate areas of high research priority for improving treatment strategies.

In Vitro Evaluation of the Effect of Storage at -20°C and Proximal Gastrointestinal Conditions on Viability of Equine Fecal Microbiota Transplant

Fecal microbiota transplant (FMT), a technique used to restore normal intestinal microbial communities, has been successful in treating humans with Clostridioides difficile colitis. Subsequently, FMT is being used in veterinary patients with suspected intestinal dysbiosis. Unfortunately, little data are available regarding best practices for FMT in horses. The objective of this study was to evaluate the effects of storing manure prepared for equine FMT (MP-FMT) at -20°C for up to 4 weeks and passage through a simulated proximal gastrointestinal (GI) tract on the viability of MP-FMT. The results of this study indicate that storage at -20°C for greater than 1 week and exposure to conditions consistent with the proximal GI tract significantly decreased viability of the microbial population, with gram-negative enteric bacteria most significantly impacted. This preliminary evaluation indicates that further work is necessary to determine best practices to preserve the viability MP-FMT in horses.