Can fecal microbiota transplantation cure irritable bowel syndrome?

Pharmacological effects of ginseng and ginsenosides on intestinal inflammation and the immune system

Intestinal inflammatory imbalance and immune dysfunction may lead to a spectrum of intestinal diseases, such as inflammatory bowel disease (IBD) and gastrointestinal tumors. As the king of herbs, ginseng has exerted a wide range of pharmacological effects in various diseases. Especially, it has been shown that ginseng and ginsenosides have strong immunomodulatory and anti-inflammatory abilities in intestinal system. In this review, we summarized how ginseng and various extracts influence intestinal inflammation and immune function, including regulating the immune balance, modulating the expression of inflammatory mediators and cytokines, promoting intestinal mucosal wound healing, preventing colitis-associated colorectal cancer, recovering gut microbiota and metabolism imbalance, alleviating antibiotic-induced diarrhea, and relieving the symptoms of irritable bowel syndrome. In addition, the specific experimental methods and key control mechanisms are also briefly described.

Moxibustion improved the effect of fecal microbiota transplantation donor to dextran sulfate sodium-induced colitis in mice

Fecal microbiota transplantation (FMT) is beneficial for several gastrointestinal diseases because it alters the intestinal microbiota of recipients. The efficacy of FMT is related to the microbial structure and composition of the donor. Mild moxibustion is a non-invasive and safe traditional Chinese therapy that can regulate the gut microbiota. In this study, we investigated whether moxibustion improved the efficacy of FMT in donors using a dextran sulfate sodium (DSS)-induced colitis mouse model. Normal mice were treated with mild moxibustion at acupoints ST25 and ST36 for 7 days. DSS (2%) was administered for 7 days to induce colitis. FMT was performed on Day 8 and lasted for 7 days. The effect of FMT on mice with DSS was observed on Day 21. Using hematoxylin and eosin staining and immunofluorescence, we analyzed the pathology and cell proliferation after FMT in DSS mice. In addition, using 16 S rDNA sequencing analysis, we investigated the gut microbiota of mice. The results indicated that moxibustion altered the colonic microbial community and increased the relative abundance of specific bacteria without changes in morphology and physiological function in normal mice. FMT using donors with moxibustion reduced body weight loss, inflammation, abnormal microbial community structure, and the relative abundance of some bacteria. These results provide potential strategies for the safe and targeted improvement of FMT donors.

Targeting gut microbiota: new therapeutic opportunities in multiple sclerosis

Multiple sclerosis (MS) causes long-lasting, multifocal damage to the central nervous system. The complex background of MS is associated with autoimmune inflammation and neurodegeneration processes, and is potentially affected by many contributing factors, including altered composition and function of the gut microbiota. In this review, current experimental and clinical evidence is presented for the characteristics of gut dysbiosis found in MS, as well as for its relevant links with the course of the disease and the dysregulated immune response and metabolic pathways involved in MS pathology. Furthermore, therapeutic implications of these investigations are discussed, with a range of pharmacological, dietary and other interventions targeted at the gut microbiome and thus intended to have beneficial effects on the course of MS.

Fecal microbiota transplantation for the treatment of irritable bowel syndrome: A systematic review and meta-analysis

BACKGROUND

Irritable bowel syndrome (IBS) is the most prevalent gastrointestinal disorder in developed countries and reduces patients’ quality of life, hinders their ability to work, and increases health care costs. A growing number of trials have demonstrated an aberrant gut microbiota composition in IBS, also known as ‘gut dysbiosis’. Fecal microbiota transplantation (FMT) has been suggested as a treatment for IBS.

AIM

To assess the efficacy and safety of FMT for the treatment of IBS.

METHODS

We searched Cochrane Central, MEDLINE, EMBASE and Web of Science up to 24 October 2022 for randomised controlled trials (RCTs) investigating the effectiveness of FMT compared to placebo (including autologous FMT) in treating IBS. The primary outcome was the number of patients with improvements of symptoms measured using a validated, global IBS symptoms score. Secondary outcomes were changes in quality-of-life scores, non-serious and serious adverse events. Risk ratios (RR) and corresponding 95%CI were calculated for dichotomous outcomes, as were the mean differences (MD) and 95%CI for continuous outcomes. The Cochrane risk of bias tool was used to assess the quality of the trials. GRADE criteria were used to assess the overall quality of the evidence.

RESULTS

Eight RCTs (484 participants) were included in the review. FMT resulted in no significant benefit in IBS symptoms three months after treatment compared to placebo (RR 1.19, 95%CI: 0.68-2.10). Adverse events were reported in 97 participants in the FMT group and in 45 participants in the placebo group (RR 1.17, 95%CI: 0.63-2.15). One serious adverse event occurred in the FMT group and two in the placebo group (RR 0.42, 95%CI: 0.07-2.60). Endoscopic FMT delivery resulted in a significant improvement in symptoms, while capsules did not. FMT did not improve the quality of life of IBS patients but, instead, appeared to reduce it, albeit non significantly (MD -6.30, 95%CI: -13.39-0.79). The overall quality of the evidence was low due to moderate-high inconsistency, the small number of patients in the studies, and imprecision.

CONCLUSION

We found insufficient evidence to support or refute the use of FMT for IBS. Larger trials are needed.

Fecal microbiota transplantation in patients with post-infectious irritable bowel syndrome: A randomized, clinical trial

Introduction

Research in recent years has shown the potential benefits of fecal microbiota transplantation (FMT) for irritable bowel syndrome (IBS). Acute infectious gastroenteritis is a well-established risk factor for developing such forms of IBS as post-infectious IBS (PI-IBS). However, the effective use of FMT in patients with IP-IBS has not yet been clarified.

Aim

The study aimed to conduct a single-center, randomized clinical trial (RCT) to assess FMT’s safety, clinical and microbiological efficacy in patients with PI-IBS.

Materials and methods

Patients with PI-IBS were randomized into two groups: I (standard-care, n = 29) were prescribed basic therapy, namely a low FODMAP diet, as well as Otilonium Bromide (1 tablet TID) and a multi-strain probiotic (1 capsule BID) for 1 month; II (FMT group, n = 30), each patient with PI-IBS underwent a single FMT procedure with fresh material by colonoscopy. All patients underwent bacteriological examination of feces for quantitative and qualitative microbiota composition changes. The clinical efficacy of treatment was evaluated according to the dynamics of abdominal symptoms, measured using the IBS-SSS scale, fatigue reduction (FAS scale), and a change in the quality of life (IBS-QoL scale).

Results

FMT was associated with rapid onset of the effect, manifested in a significant difference between IBS-SSS points after 2 weeks of intervention (p < 0.001). In other time points (after 4 and 12 weeks) IBS-SSS did not differ significantly across both groups. Only after 3 months of treatment did their QoL exceed its initial level, as well value for 2 and 4 weeks, to a significant extent. The change in the ratio of the main microbial phenotypes in the form of an increase in the relative abundance of Firmicutes and Bacteroidetes was recorded in all patients after 4 weeks. It should be noted that these changes were significant but eventually normalized only in the group of PI-IBS patients who underwent FMT. No serious adverse reactions were noted.

Conclusion

This comparative study of the results of FMT use in patients with PI-IBS demonstrated its effectiveness compared to traditional pharmacotherapy, as well as a high degree of safety and good tolerability.

Is the Gut Microbiota a Neglected Aspect of Gut and Brain Disorders?

The gut microbiota is a quickly developing bacterial ecosystem with biodiversity. It is an adaptive immunity that varies with food intake, environmental conditions, and human habits, among other factors. Various external stimuli, such as drugs, can influence the gut microbial environment and lead to gut dysbiosis. Recently, gut dysbiosis has been identified as an important factor that leads to several diseases either by the released metabolites or by the gut neuronal connection. In brain disorders, gut dysbiosis is involved in neuropsychiatric manifestations, including autism spectrum disorder, anxiety, and depression by interfering with neurotransmitter homeostasis, and neurodegenerative diseases, such as Alzheimer’s disease and Parkinson’s disease by releasing abnormal metabolites from the gut. Gut dysbiosis has been documented in gut disorders, including inflammatory bowel disease or irritable bowel syndrome. Immune cells in the gut are modulated by external factors such as stress, diet, and drugs to produce inflammatory cytokines, including interleukins (IL-4, IL-6, IL-17, IL-23, etc.). Inflammatory cytokines lead to a cascade of events, which lead to various ailments in the bowel. Beneficial bacteria in the form of probiotics ameliorate the condition and have healthful effects in disease conditions. This warrants further research to identify newer therapeutic strategies for diseases that cannot be cured or are difficult to treat.

Effects of red ginseng on gut, microbiota, and brain in a mouse model of post-infectious irritable bowel syndrome

Background

Irritable bowel syndrome (IBS), the most common functional gastrointestinal disorder, is characterized by chronic abdominal pain and bowel habit changes. Although diverse complicated etiologies are involved in its pathogenesis, a dysregulated gut–brain axis may be an important factor. Red ginseng (RG), a traditional herbal medicine, is proven to have anti-inflammatory effects and improve brain function; however, these effects have not been investigated in IBS.

Methods

Three-day intracolonic zymosan injections were used to induce post-infectious human IBS-like symptoms in mice. The animals were randomized to receive either phosphate-buffered saline (CG) or RG (30/100/300 mg/kg) for 10 days. Amitriptyline and sulfasalazine were used as positive controls. Macroscopic scoring was performed on day 4. Visceral pain and anxiety-like behaviors were assessed by colorectal distension and elevated plus maze and open field tests, respectively, on day 10. Next-generation sequencing of gut microbiota was performed, and biomarkers involved in gut–brain axis responses were analyzed.

Results

Compared to CG, RG significantly decreased the macroscopic score, frequency of visceral pain, and anxiety-like behavior in the IBS mice. These effects were comparable to those after sulfasalazine and amitriptyline treatments. Moreover, RG significantly increased the proliferation of beneficial microbes, including Lactobacillus johnsonii, Lactobacillus reuteri, and Parabacteroides goldsteinii. RG significantly suppressed expression of IL-1β and c-fos in the gut and prefrontal cortex, respectively. Further, it restored the plasma levels of corticosterone to within the normal range, accompanied by an increase in adrenocorticotropic hormone.

Conclusion

RG may be a potential therapeutic option for the management of human IBS.

Schizophrenia, the gut microbiota, and new opportunities from optogenetic manipulations of the gut-brain axis

Schizophrenia research arose in the twentieth century and is currently rapidly developing, focusing on many parallel research pathways and evaluating various concepts of disease etiology. Today, we have relatively good knowledge about the generation of positive and negative symptoms in patients with schizophrenia. However, the neural basis and pathophysiology of schizophrenia, especially cognitive symptoms, are still poorly understood. Finding new methods to uncover the physiological basis of the mental inabilities related to schizophrenia is an urgent task for modern neuroscience because of the lack of specific therapies for cognitive deficits in the disease. Researchers have begun investigating functional crosstalk between NMDARs and GABAergic neurons associated with schizophrenia at different resolutions. In another direction, the gut microbiota is getting increasing interest from neuroscientists. Recent findings have highlighted the role of a gut-brain axis, with the gut microbiota playing a crucial role in several psychopathologies, including schizophrenia and autism.

There have also been investigations into potential therapies aimed at normalizing altered microbiota signaling to the enteric nervous system (ENS) and the central nervous system (CNS). Probiotics diets and fecal microbiota transplantation (FMT) are currently the most common therapies. Interestingly, in rodent models of binge feeding, optogenetic applications have been shown to affect gut colony sensitivity, thus increasing colonic transit. Here, we review recent findings on the gut microbiota–schizophrenia relationship using in vivo optogenetics. Moreover, we evaluate if manipulating actors in either the brain or the gut might improve potential treatment research. Such research and techniques will increase our knowledge of how the gut microbiota can manipulate GABA production, and therefore accompany changes in CNS GABAergic activity.

Deposition of resistant bacteria and resistome through FMT in germ-free piglets

Faecal microbiota transplantation (FMT) has received considerable attention in recent years due to its remarkable efficacy in restoring a normal gut microbiome. Here, we established the groups of post-FMT recipient piglets using germ-free piglets during early life to characterize the colonization of gut microbiota composition and the enrichment of resistance gene acquisition. By metagenomic analysis, we identified 115 bacterial phyla and 2111 bacterial genera that were acquired by the FMT recipients. We found that early-life microbial colonization and the spread of resistomes in recipient piglets were age dependent. A total of 425, 425 and 358 AR genes primarily belonging to 114, 114 and 102 different types were detected in the donors, post-FMT recipients in the FMT-3D group and post-FMT recipients in the FMT-15D group respectively. Genes that encoded tetracycline, macrolide and chloramphenicol resistance proteins were the most dominant AR genes, and the results corresponded with the exposure of antibiotic consumption at farm. Bacteroides, Escherichia, Clostridium, Parabacteroides, Treponema, Lactobacillus and Enterococcus were significantly correlated with the distribution of AR genes. More importantly, the relative abundance of AR genes was positively correlated with the levels of mobile genetic elements. Our results indicate that early-life microbial colonization can persistently shape the gut microbiota and antibiotic resistome.

High and Mighty? Cannabinoids and the microbiome in pain

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In this review, we will focus on the potential role of the endogenous cannabinoids in modulating microbiota-driven changes in peripheral and central pain processing.

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We also focus on the overlap in mechanisms whereby commensal gut microbiota and endocannabinoid ligands can regulate inflammation and further aim to exploit our understanding of their role in microbiota-gut-brain axis communication in pain processing.

Within the human gut, we each harbour a unique ecosystem represented by trillions of microbes that contribute to our health and wellbeing. These gut microbiota form part of a complex network termed the microbiota-gut-brain axis along with the enteric nervous system, sympathetic and parasympathetic divisions of the autonomic nervous system, and neuroendocrine and neuroimmune components of the central nervous system. Through endocrine, immune and neuropeptide/neurotransmitter systems, the microbiota can relay information about health status of the gut. This in turn can profoundly impact neuronal signalling not only in the periphery, but also in the brain itself and thus impact on emotional systems and behavioural responses. This may be true for pain, as the top-down facilitation or inhibition of pain processing occurs at a central level, while ascending afferent nociceptive information from the viscera and systemic areas travel through the periphery and spinal cord to the brain. The endogenous cannabinoid receptors are ubiquitously expressed throughout the gut, periphery and in brain regions associated with pain responding, and represent targets for endogenous and exogenous manipulation. In this review, we will focus on the potential role of the endogenous cannabinoids in modulating microbiota-driven changes in peripheral and central pain processing. We also focus on the overlap in mechanisms whereby commensal gut microbiota and endocannabinoid ligands can regulate inflammation and further aim to exploit our understanding of their role in microbiota-gut-brain axis communication in pain processing.

Gut Microbiota-Bile Acid Crosstalk in Diarrhea-Irritable Bowel Syndrome

The occurrence of diarrhea-predominant irritable bowel syndrome (IBS-D) is the result of multiple factors, and its pathogenesis has not yet been clarified. Emerging evidence indicates abnormal changes in gut microbiota and bile acid (BA) metabolism have a close relationship with IBS-D. Gut microbiota is involved in the secondary BA production via deconjugation, 7α-dehydroxylation, oxidation, epimerization, desulfation, and esterification reactions respectively. Changes in the composition and quantity of gut microbiota have an important impact on the metabolism of BAs, which can lead to the occurrence of gastrointestinal diseases. BAs, synthesized in the hepatocytes, play an important role in maintaining the homeostasis of gut microbiota and the balance of glucose and lipid metabolism. In consideration of the complex biological functional connections among gut microbiota, BAs, and IBS-D, it is urgent to review the latest research progress in this field. In this review, we summarized the alterations of gut microbiota in IBS-D and discussed the mechanistic connections between gut microbiota and BA metabolism in IBS-D, which may be involved in activating two important bile acid receptors, G-protein coupled bile acid receptor 1 (TGR5) and farnesoid X receptor (FXR). We also highlight the strategies of prevention and treatment of IBS-D via regulating gut microbiota-bile acid axis, including probiotics, fecal microbiota transplantation (FMT), cholestyramine, and the cutting-edge technology about bacteria genetic engineering.

Gut microbiota and therapeutic approaches for dysbiosis in irritable bowel syndrome: recent developments and future perspectives

Increased knowledge regarding the implications of gut microbiota in irritable bowel syndrome (IBS) suggests that a disturbed intestinal microenvironment (dysbiosis) might promote the development and maintenance of IBS symptoms and affects several pathways in the pathology of this multifactorial disease. Accordingly, manipulation of the gut microbiota in order to improve IBS symptoms has evolved as a novel treatment strategy in the last decade. Several different approaches have been investigated in order to improve the gut microbiota composition. Dietary modifications including supplementation with fibers, prebiotics, and probiotics are shown to improve symptoms and composition of gut microbiota in IBS; however, the exact probiotic mixture beneficial for each individual remains to be identified. The use of antibiotics still needs confirmation, although promising results have been reported with use of rifaximin. Fecal microbiota transplantation (FMT) has recently gained a lot of attention, and several placebo-controlled trials investigating FMT obtain promising results regarding symptom reduction and gut microbiota manipulation in IBS. However, more data regarding long-term effects are needed before FMT can be integrated as a customized treatment for IBS in the clinical routine.

An ecological framework to understand the efficacy of fecal microbiota transplantation

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

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

Australian consensus statements for the regulation, production and use of faecal microbiota transplantation in clinical practice

OBJECTIVE

Faecal microbiota transplantation (FMT) has proved to be an extremely effective treatment for recurrent Clostridioides difficile infection, and there is interest in its potential application in other gastrointestinal and systemic diseases. However, the recent death and episode of septicaemia following FMT highlights the need for further appraisal and guidelines on donor evaluation, production standards, treatment facilities and acceptable clinical indications.

DESIGN

For these consensus statements, a 24-member multidisciplinary working group voted online and then convened in-person, using a modified Delphi approach to formulate and refine a series of recommendations based on best evidence and expert opinion. Invitations to participate were directed to Australian experts, with an international delegate assisting the development. The following issues regarding the use of FMT in clinical practice were addressed: donor selection and screening, clinical indications, requirements of FMT centres and future directions. Evidence was rated using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system.

RESULTS

Consensus was reached on 27 statements to provide guidance on best practice in FMT. These include: (1) minimum standards for donor screening with recommended clinical selection criteria, blood and stool testing; (2) accepted routes of administration; (3) clinical indications; (4) minimum standards for FMT production and requirements for treatment facilities acknowledging distinction between single-site centres (eg, hospital-based) and stool banks; and (5) recommendations on future research and product development.

CONCLUSIONS

These FMT consensus statements provide comprehensive recommendations around the production and use of FMT in clinical practice with relevance to clinicians, researchers and policy makers.

Targeting the gut microbiota for the treatment of irritable bowel syndrome

Irritable bowel syndrome (IBS) is a chronic gastrointestinal disorder that affects an estimated 11% of people across the world. IBS patients are one of the largest subgroups seen in gastroenterology clinics, exhibit a lesser quality of life, and take greater use of the healthcare system. The exact etiology of IBS remains uncertain. Alterations in the gut microbiome may characterize apotential mechanism in the pathogenesis of IBS. This hypothesis is paralleled by rodent models in which manipulation of the gut microbiota leads to disturbed physiological functions along the brain-gut axis. Recent research in IBS treatments has redirected its focus towards gu microbiome based therapeutics. In this review, we discuss potential roles of enteric bacteria in the pathogenesis of IBS and its comorbidities. We then explore the manipulation of the enteric microbiota by prebiotics, probiotics, antibiotics, dietary changes, and fecal microbiota transfer. We also discuss the positive and negative effects of these therapeutics on IBS symptoms.

New insights into irritable bowel syndrome: from pathophysiology to treatment

Irritable bowel syndrome (IBS) is the most common reason to visit a gastroenterologist. IBS was believed to be a functional disease, but many possible pathophysiologic mechanisms can now explain the symptoms. IBS patients are classified into subtypes according to their predominant bowel habit, based on the Rome IV criteria. These include diarrhea-predominant and constipation-predominant IBS, as well as the mixed type, a combination of the two. Usually, IBS treatment is based on the predominant symptoms, with many options for each subtype. A new promising treatment option, fecal microbiota transplantation, seems to have beneficial effects on IBS. However, treating the pathophysiological causative agent responsible for the symptoms is an emerging approach. Therefore, before the appropriate therapeutic option is chosen for treating IBS, a clinical evaluation of its pathophysiology should be performed.

Fecal microbiota transplantation in irritable bowel syndrome: A systematic review and meta-analysis

Background

Modulating gut microbiota is a potential treatment for irritable bowel syndrome (IBS). This meta-analysis explored whether fecal microbiota transplantation (FMT) is successful in treating IBS.

Methods

A systematic review was performed to find trials on FMT in IBS. Ratios and relative ratios (RR) of improvement for single-arm trials (SATs) and randomized controlled trials (RCTs) were calculated, respectively. Changes in IBS Severity Scoring System (IBS-SSS) and IBS Quality of Life (IBS-QOL) instrument compared to baseline in FMT versus placebo groups were pooled.

Results

In SATs, 59.5% (95% confidence interval (CI) 49.1-69.3) of IBS patients showed significant improvement. In RCTs, there were no differences between FMT and control in improvement (RR=0.93 (95% CI 0.50-1.75)) or changes in the IBS-SSS and IBS-QOL.

Conclusions

FMT was not effective in IBS. Variations in FMT methods and patient factors may contribute to the heterogeneous results of the trials.

The comprehensive pathophysiological changes in a novel rat model of postinflammatory visceral hypersensitivity

So far, a comprehensive animal model that can mimic both the central and peripheral pathophysiological changes of irritable bowel syndrome (IBS) is lacking. Here, we developed a novel IBS rat model combining trinitro-benzene-sulfonic acid (TNBS) and chronic unpredictable mild stress (CUMS) (designated as TC-IBS) and compared it with the TNBS-induced and CUMS-induced models. TC-IBS showed a pronounced depression phenotype with increased corticotropin-releasing hormone receptor (CRHR)1 and CRHR2 expression at the frontal cortex and increased serum ACTH concentration. Visceral hypersensitivity (VH), as evidenced by colorectal distention (CRD) test, was highest in TC-IBS, accompanied by increased serum 5-hydroxytryptamine (5-HT) level and colonic 5-HT receptor 3A (5-HT_3AR)/5-HT receptor 2B expression, impaired tight junction protein expression including occludin, zonula occludens-1, and phosphorylated myosin light chain. Palonosetron, a second generation of 5-HT_3AR antagonist, alleviated VH significantly in TC-IBS. 16S rRNA sequencing showed that TNBS plus CUMS induced a significant disturbance of the gut microbiota. Cytokine profile analysis of TC-IBS model indicated an innate immune activation both in serum and colonic mucosa. Further, fecal microbiota transplantation improved VH and some pathophysiological changes in TC-IBS. In summary, we established a postinflammatory IBS model covering multifactorial pathophysiological changes, which may help to develop therapies that target specific IBS subtype.-Ma, J., Li, J., Qian, M., He, N., Cao, Y., Liu, Y., Wu, K., He, S. The comprehensive pathophysiological changes in a novel rat model of postinflammatory visceral hypersensitivity.

Efficacy of Fecal Microbiota Transplantation in Irritable Bowel Syndrome: A Systematic Review and Meta-Analysis

OBJECTIVES

Irritable bowel syndrome (IBS) is a common gastrointestinal condition with a heterogeneous pathophysiology. An altered gut microbiome has been identified in some IBS patients, and fecal microbiota transplantation (FMT) has been suggested to treat IBS. We performed meta-analyses and systematic review of available randomized controlled trials (RCTs) to evaluate the efficacy of FMT in IBS.

METHODS

We performed a systematic literature search of MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Web of Science. Selection criteria included RCTs of FMT vs placebo using FMT excipients or autologous FMT in IBS. Meta-analyses were conducted to evaluate the summary relative risk (RR) and 95% confidence intervals (CIs) of combined studies for primary outcome of improvement in global IBS symptoms as measured by accepted integrative symptom questionnaires or dichotomous responses to questions of overall symptom improvement.

RESULTS

Among 742 citations identified, 7 were deemed to be potentially relevant, of which 4 studies involving 254 participants met eligibility. No significant difference in global improvement of IBS symptoms was observed at 12 weeks in FMT vs placebo (RR = 0.93; 95% CI 0.48-1.79). Heterogeneity among studies was significant (I = 79%). Subgroup analyses revealed benefits of single-dose FMT using colonoscopy and nasojejunal tubes in comparison with autologous FMT for placebo treatment (number needed to treat = 5, RR = 1.59; 95% CI 1.06-2.39; I = 0%) and a reduction in likelihood of improvement of multiple-dose capsule FMT RCTs (number needed to harm = 3, RR = 0.54; 95% CI 0.34-0.85; I = 13%). Placebo response was 33.7% in nonoral FMT RCTs and 67.8% in capsule FMT RCTs. The Grading of Recommendations Assessment, Development and Evaluation quality of the body of evidence was very low.

DISCUSSION

Current evidence from RCTs does not suggest a benefit of FMT for global IBS symptoms. There remain questions regarding the efficacy of FMT in IBS as well as the lack of a clean explanation on the discrepant results among RCTs in subgroup analyses.

The Microbiome and Irritable Bowel Syndrome - A Review on the Pathophysiology, Current Research and Future Therapy

Irritable bowel syndrome (IBS) is a functional disorder which affects a large proportion of the population globally. The precise etiology of IBS is still unknown, although consensus understanding proposes IBS to be of multifactorial origin with yet undefined subtypes. Genetic and epigenetic factors, stress-related nervous and endocrine systems, immune dysregulation and the brain-gut axis seem to be contributing factors that predispose individuals to IBS. In addition to food hypersensitivity, toxins and adverse life events, chronic infections and dysbiotic gut microbiota have been suggested to trigger IBS symptoms in tandem with the predisposing factors. This review will summarize the pathophysiology of IBS and the role of gut microbiota in relation to IBS. Current methodologies for microbiome studies in IBS such as genome sequencing, metagenomics, culturomics and animal models will be discussed. The myriad of therapy options such as immunoglobulins (immune-based therapy), probiotics and prebiotics, dietary modifications including FODMAP restriction diet and gluten-free diet, as well as fecal transplantation will be reviewed. Finally this review will highlight future directions in IBS therapy research, including identification of new molecular targets, application of 3-D gut model, gut-on-a-chip and personalized therapy.

Current applications of fecal microbiota transplantation in intestinal disorders

Fecal microbiota transplantation (FMT) had been an ancient remedy for severe illness several centuries ago. Under modern medical analysis and evidence-based research, it has been proved as an alternative treatment for recurrent Clostridium difficile infection and recent randomized control study also showed that FMT could be an adjuvant treatment for inflammatory bowel disease. As we get a better understanding of the relationship between gut microbiota and systemic disease, FMT became a potential treatment to explore. This article summarized procedures such as donor selection, fecal material preparation, transplantation delivery methods, and adverse events. We also review the present evidence about FMT in clinical practice.

The efficacy of fecal microbiota transplantation for patients with chronic pouchitis: A case series

Pouchitis is one of the most common complications that develop after restorative proctocolectomy with ileal pouch-anal anastomosis for ulcerative colitis. Single fecal microbiota transplantation (FMT) by colonoscopy was performed safely on three patients with pouchitis. However, the efficacy of FMT on pouchitis was limited.

Differences in gut microbiota associated with age, sex, and stool consistency in healthy Japanese subjects

BACKGROUND

Human gut microbiota is involved in host health and disease development. Investigations of age-related and sex-related alterations in gut microbiota are limited, and the association between stool consistency and gut microbiota has not been fully investigated. We investigated gut microbiota differences related to age, sex, and stool consistency in healthy Japanese subjects.

METHODS

Two-hundred and seventy-seven healthy Japanese subjects aged 20-89 years were enrolled. Fecal samples were obtained to analyze the gut microbiome. We evaluated the association between stool consistency [Bristol stool scale (BSS)] and gut microbiota.

RESULTS

Although there were significant differences in the microbial structure between males and females, the α-diversity of gut microbiota showed no difference between males and females or among age groups. There were significant increases in genera Prevotella, Megamonas, Fusobacterium, and Megasphaera and Bifidobacterium, Ruminococcus, and Akkermansia in males and females, respectively. The ratio of hard stools (BSS types 1 and 2) was higher in females; the ratio of loose stools (BSS type 6) was higher in males. No younger male had BSS type 1 or type 2. Fusobacterium in males was significantly higher in the loose consistency group, and Oscillospira was significantly higher in the hard consistency group in males; Campylobacter, SMB53, and Turicibacter were significantly higher in the hard consistency group in females.

CONCLUSIONS

Several changes in gut microbiota were associated with age and sex. Stool consistency and gut microbiota associations emphasized the importance of stool consistency assessments to understand intestinal function.

Comprehensive review of neuromyelitis optica and clinical characteristics of neuromyelitis optica patients in Puerto Rico

Neuromyelitis optica (NMO) is an immune-mediated inflammatory disorder of the central nervous system. It is characterized by concurrent inflammation and demyelination of the optic nerve (optic neuritis [ON]) and the spinal cord (myelitis). Multiple studies show variations in prevalence, clinical, and demographic features of NMO among different populations. In addition, ethnicity and race are known as important factors on disease phenotype and clinical outcomes. There are little data on information about NMO patients in underserved groups, including Puerto Rico (PR). In this research, we will provide a comprehensive overview of all aspects of NMO, including epidemiology, environmental risk factors, genetic factors, molecular mechanism, symptoms, comorbidities and clinical differentiation, diagnosis, treatment, its management, and prognosis. We will also evaluate the demographic features and clinical phenotype of NMO patients in PR. This will provide a better understanding of NMO and establish a basis of knowledge that can be used to improve care. Furthermore, this type of population-based study can distinguish the clinical features variation among NMO patients and will provide insight into the potential mechanisms that cause these variations.

Faecal microbiota transplantation alters gut microbiota in patients with irritable bowel syndrome: results from a randomised, double-blind placebo-controlled study

OBJECTIVE

IBS is associated with an intestinal dysbiosis and faecal microbiota transplantation (FMT) has been hypothesised to have a positive effect in patients with IBS. We performed a randomised, double-blind placebo-controlled trial to investigate if FMT resulted in an altered gut microbiota and improvement in clinical outcome in patients with IBS.

DESIGN

We performed this study in 52 adult patients with moderate-to-severe IBS. At the screening visit, clinical history and symptoms were assessed and faecal samples were collected. Patients were randomised to FMT or placebo capsules for 12 days and followed for 6 months. Study visits were performed at baseline, 1, 3 and 6 months, where patients were asked to register their symptoms using the IBS-severity scoring system (IBS-SSS) and IBS-specific quality of life (IBS-QoL). Prior to each visit, faecal samples were collected.

RESULTS

A significant difference in improvement in IBS-SSS score was observed 3 months after treatment (p=0.012) favouring placebo. This was similar for IBS-QoL data after 3 months (p=0.003) favouring placebo. Patients receiving FMT capsules had an increase in faecal microbial biodiversity while placebos did not.

CONCLUSION

In this randomised double-blinded placebo-controlled study, we found that FMT changed gut microbiota in patients with IBS. But patients in the placebo group experienced greater symptom relief compared with the FMT group after 3 months. Altering the gut microbiota is not enough to obtain clinical improvement in IBS. However, different study designs and larger studies are required to examine the role of FMT in IBS.

TRIAL REGISTRATION NUMBER

NCT02788071.

Clinical Application and Potential of Fecal Microbiota Transplantation

Fecal microbiota transplantation (FMT) is a well-established treatment for recurrent Clostridioides difficile infection. FMT has become a more readily available and useful new treatment option as a result of stool banks. The current state of knowledge indicates that dysbiosis of the gut microbiota is implicated in several disorders in addition to C. difficile infection. Randomized controlled studies have shown FMT to be somewhat effective in treating ulcerative colitis, irritable bowel syndrome, and hepatic encephalopathy. In addition, FMT has been beneficial in treating several other conditions, such as the eradication of multidrug-resistant organisms and graft-versus-host disease. We expect that FMT will soon be implemented as a treatment strategy for several new indications, although further studies are needed.

Non-alcoholic fatty liver disease and obesity: the role of the gut bacteria

Non-alcoholic fatty-liver disease (NAFLD) is now considered one of the leading causes of liver disease worldwide and is associated with metabolic syndrome and obesity. There are several factors contributing to the disease state. Recent research suggests that the intestinal microbiota (IM) and bacterial products may play a role through several mechanisms which include increased energy uptake, intestinal permeability and chronic inflammation. In addition to diet and exercise, treatment options targeting the IM are being investigated and include the use of pre-, pro- and synbiotics as well as the possibility of fecal microbial transfers. This literature review explores the relationship between NAFLD and the IM as well as highlight new IM treatment options that may become available in the near future.

New treatments and therapeutic targets for IBS and other functional bowel disorders

Functional bowel disorders (FBDs) are a spectrum of disorders characterized by combinations of symptoms attributable to the lower gastrointestinal tract. Most current first-line therapies for IBS and other FBDs target the predominant symptom and mainly affect one symptom in the symptom complex. Additional broadly effective treatment alternatives targeting the entire symptom complex are needed. New drugs for FBDs (such as lubiprostone, linaclotide, plecanatide, prucalopride, eluxadoline and rifaximin) target key mechanisms in the pathophysiology of these disorders and improve both the abnormal bowel habit and other key symptoms, such as abdominal pain and bloating. The current development of new treatment alternatives is focusing on different aspects of the complex pathophysiology of IBS and other FBDs: gut microenvironment (via diet and modulation of gut microbiota), enterohepatic circulation of bile acids, gastrointestinal secretion, motility and sensation, gut-brain interactions, gut barrier function and the immune system within the gastrointestinal tract. Studies also suggest that personalized treatment of IBS and other FBDs is possible using various diagnostic markers.

Fecal microbiota transfer for bowel disorders: efficacy or hype?

PURPOSE OF REVIEW

Dysbiosis has been related to the pathophysiology of disorders of - gut-brain interaction (DGBI) including irritable bowel syndrome (IBS) and functional constipation (FC). Accordingly, modulation of gut microbiota has been proposed as a potential treatment for these disorders. Gut microbiota modulation can be effected by probiotics, prebiotics, symbiotics, postbiotics, antibiotics and fecal transplantation (FMT) or bacteriotherapy. The latter is currently used for recurrent or severe Clostridium difficile colitis and has been the focus of recent research in IBS and FC.

RECENT FINDINGS

Several case series reported promising results for FMT in patients with IBS and FC, which prompted the conduction of randomized controlled trials (RCT) in these DGBI.

SUMMARY

Both case series and RCTs are herein discussed. To the best of our knowledge, as of yet, 5 RCTs have been published on IBS and one in FC with slow colonic transit. In IBS, the majority of studies have used the IBS severity scoring system (IBS-SSS) as an outcome measure; however, the selection criteria were different among the trials as well as the route and form of administration of the FMT. Therefore, the results are inconsistent and no conclusion can be drawn. Some studies suggest that the presence of post-infection (PI)-IBS and the baseline microbiota status in the donors could be predictor factors of successful FMT in IBS. In constipation with slow colonic transit, the FMT seems to be more effective, although the data is based on only one RCT. We believe that larger RCTs, controlled with true placebos and considering baseline intestinal microbiota of the study subjects as well as donors' microbiota are still needed before recommending FMT in IBS and/or FC. History of previous GI infection (e.g. PI-IBS) and IBS subtypes should also be taken into account.

Healthy hosts rule within: ecological forces shaping the gut microbiota

A balanced gut microbiota is important for human health, but the mechanisms that maintain homeostasis are incompletely understood. Recent insights suggest the host plays a key role in shaping its gut microbiota to be beneficial. While host control in the small intestine curbs bacterial numbers to avoid competition for simple sugars and amino acids, the host limits oxygen availability in the large intestine to obtain microbial fermentation products from fiber. Epithelial cells are major players in imposing ecological control mechanisms, which involves the release of antimicrobial peptides by small-intestinal Paneth cells and maintenance of luminal anaerobiosis by epithelial hypoxia in the colon. Harnessing these epithelial control mechanisms for therapeutic means could provide a novel lynchpin for strategies to remediate dysbiosis.

The effect of fecal microbiota transplantation on psychiatric symptoms among patients with irritable bowel syndrome, functional diarrhea and functional constipation: An open-label observational study

BACKGROUNDS

The intestinal microbiota is considered as a potential common underpinning pathophysiology of Functional Gastrointestinal Disorders (FGIDs) and psychiatric disorders such as depression and anxiety. Fecal Microbiota Transplantation (FMT) has been reported to have therapeutic effects on diseases related to dysbiosis, but few studies have evaluated its effect on psychiatric symptoms.

METHODS

We followed 17 patients with either Irritable Bowel Syndrome (IBS), Functional Diarrhea (FDr) or Functional Constipation (FC) who underwent FMT for the treatment of gastrointestinal symptoms and observation of psychiatric symptoms. Changes in Hamilton Rating Scale for Depression (HAM-D) and subscale of sleep-related items, Hamilton Rating Scale for Anxiety (HAM-A) and Quick Inventory for Depressive Symptoms (QIDS) between baseline and 4 weeks after FMT, and relationship with the intestinal microbiota were measured.

RESULTS

At baseline, 12 out of 17 patients were rated with HAM-D ≥ 8. Significant improvement in HAM-D total and sleep subscale score, HAM-A and QIDS were observed (p = 0.007, p = 0.007, p = 0.01, p = 0.007, respectively). Baseline Shannon index indicated that microbiota showed lower diversity in patients with HAM-D ≥ 8 compared to those of healthy donors and patients with HAM-D < 8. There was a significant correlation between baseline Shannon index and HAM-D score, and a correlation between Shannon index change and HAM-D improvement after FMT.

LIMITATIONS

The small sample size with no control group.

CONCLUSIONS

Our results suggest that depression and anxiety symptoms may be improved by FMT regardless of gastrointestinal symptom change in patients with IBS, FDr and FC, and the increase of microbiota diversity may help to improve patient's mood.

Microbiota Replacement Therapies: Innovation in Gastrointestinal Care

There has been an increasing interest in the association between human disease and altered gut microbiota, and therapeutics to modulate microbiota to treat disease. Healthy human gastrointestinal microbiota is highly diverse and rich, and harbors between 500 and 2,000 species. Diseases associated with dysbiotic microbiota include antibiotic-associated diarrhea, Clostridium difficile infection, multidrug-resistant organisms, inflammatory bowel disease, obesity, metabolic syndrome, diabetes mellitus, neuropsychiatric diseases, and systemic autoimmune diseases. Microbiota replacement therapies have shown immense promise in treatment of recurrent C. difficile infection and are being studied for other indications. Microbiota replacement therapies for indications other than C. difficile infection should be performed only in research settings. There is an immense need for standardized microbiota replacement therapies for C. difficile infection. Studies are needed to elucidate long-term safety and adverse events from these therapies.

Fecal microbiota transplantation against irritable bowel syndrome? Rigorous randomized clinical trials are required

Halkjær et al searched systematically nine articles including 48 patients, and concluded that fecal microbiota transplantation (FMT) can be an ideal treatment option for irritable bowel syndrome (IBS) subjects. Regardless of the few successes in current traditional therapies (change in diet, herbal medicine and antibiotics) in IBS, a sharp increase in interests in the FMT option has been reported in the current century. However, there is a long list of unclear issues concerning the application of FMT for the treatment of IBS. Route of delivery and optimum dosage are the major concerns to consider before using in clinical practice.

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.

Host-Microbiota Mutualism in Metabolic Diseases

The intestinal microbiota is a plastic ecosystem that is shaped by environmental and genetic factors, interacting with virtually all tissues of the host. Many signals result from the interplay between the microbiota with its mammalian symbiont that can lead to altered metabolism. Disruptions in the microbial composition are associated with a number of comorbidities linked to the metabolic syndrome. Promoting the niche expansion of beneficial bacteria through diet and supplements can improve metabolic disorders. Reintroducing bacteria through probiotic treatment or fecal transplant is a strategy under active investigation for multiple pathological conditions. Here, we review the recent knowledge of microbiota's contribution to host pathology, the modulation of the microbiota by dietary habits, and the potential therapeutic benefits of reshaping the gut bacterial landscape in context of metabolic disorders such as obesity.