Gut Microbiota In Irritable Bowel Syndrome Research Articles

Effect of the combined intervention of low-FODMAPs diet and probiotics on IBS symptoms in Western China: A randomized controlled trial.

The effect of low-FODMAPs diet on irritable bowel syndrome (IBS) in Western China has not been reported. We aimed to investigate the effect of low-FODMAPs diet on IBS patients in the area and whether low-FODMAPs diet-induced alterations of microbiota could be improved through probiotics. IBS patients were randomized to the control group, low-FODMAPs diet group, probiotics group, or combined group. IBS Symptom Severity Score questionnaire (IBS-SSS) and IBS Quality of Life Score questionnaire (IBS-QOL) were completed at baseline, 2 and 4 weeks to evaluate the severity of symptoms. Fresh feces were collected for analyses of gut microbiota and short-chain fatty acids at baseline and 4 weeks after intervention. Seventy-three patients were included in the per protocol analysis. After intervention, there was significant improvement in IBS-SSS in the low-FODMAPs group (37.5%, 44.2%), probiotics group (51.4%, 62.0%), and combined group (34.1%, 40.4%) at both 2 weeks and 4 weeks, compared with the baseline (p < .05). In the low-FODMAPs group, the abundance of several microbiota (Lachnoclostridium, Enterococcus, etc.) was significantly decreased. Furthermore, after the supplementation of probiotics in the combined group, the abundance of Genus_Ruminococcus, Coprococcus, Acidaminococcus, Ruminiclostridium, Akkermansia, Eggerthella, and Oxalobacter was significantly increased, which was associated with the improvements of symptoms score in the Pearson correlation analysis. Our study confirmed the effectiveness and safety of short-term low-FODMAPs diet in IBS symptoms based on the Chinese diet in Western China. The combination of low-FODMAPs and probiotics plays a beneficial role in gut microbiota in IBS.

Gut microbiota and irritable bowel syndrome: status and prospect.

Irritable bowel syndrome (IBS) is a very common gastrointestinal disease that, although not as aggressive as tumors, affects patients' quality of life in different ways. The cause of IBS is still unclear, but more and more studies have shown that the characteristics of the gut microbiota, such as diversity, abundance, and composition, are altered in patients with IBS, compared to the healthy population, which confirms that the gut microbiota plays a crucial role in the development of IBS. This paper aims to identify the commonalities by reviewing a large body of literature. Changes in the characteristics of gut microbiota in patients with different types of IBS are discussed, relevant mechanisms are described, and the treatment modalities of gut microbiota in IBS are summarized. Although there are more clinical trials that have made good progress, more standardized, more generalized, larger-scale, multi-omics clinical studies are what is missing. Overall, gut microbiota plays a crucial role in the development of IBS, and there is even more potential for treating IBS by modulating gut microbiota.

Serine proteases and metalloproteases are highly increased in irritable bowel syndrome Tunisian patients

Serine proteases are involved in many biological processes and are associated with irritable bowel syndrome (IBS) pathology. An increase in serine protease activity has been widely reported in IBS patients. While most of the studies focused on host proteases, the contribution of microbial proteases are poorly studied. In the present study, we report the analysis of proteolytic activities in fecal samples from the first Tunisian cohort of IBS-M patients and healthy individuals. We demonstrated, for the first time, that metalloproteases activities were fourfold higher in fecal samples of IBS patients compared to controls. Of interest, the functional characterization of serine protease activities revealed a 50-fold increase in trypsin-like activities and a threefold in both elastase- and cathepsin G-like activities. Remarkably, we also showed a fourfold increase in proteinase 3-like activity in the case of IBS. This study also provides insight into the alteration of gut microbiota and its potential role in proteolytic modulation in IBS. Our results stressed the impact of the disequilibrium of serine proteases, metalloproteases and gut microbiota in IBS and the need of the further characterization of these targets to set out new therapeutic approaches.

Gut Dysbiosis in Irritable Bowel Syndrome: A Narrative Review on Correlation with Disease Subtypes and Novel Therapeutic Implications.

Irritable bowel syndrome (IBS) is a prevalent functional gastrointestinal disorder characterized by chronic abdominal pain and altered bowel habits. It can be subclassified in different subtypes according to the main clinical manifestation: constipation, diarrhea, mixed, and unclassified. Over the past decade, the role of gut microbiota in IBS has garnered significant attention in the scientific community. Emerging research spotlights the intricate involvement of microbiota dysbiosis in IBS pathogenesis. Studies have demonstrated reduced microbial diversity and stability and specific microbial alterations for each disease subgroup. Microbiota-targeted treatments, such as antibiotics, probiotics, prebiotics, synbiotics, fecal microbiota transplantation, and even diet, offer exciting prospects for managing IBS. However, definitive conclusions are hindered by the heterogeneity of these studies. Further research should focus on elucidating the mechanisms, developing microbiome-based diagnostics, and enabling personalized therapies tailored to an individual's microbiome profile. This review takes a deep dive into the microscopic world inhabiting our guts, and its implications for IBS. Our aim is to elucidate the complex interplay between gut microbiota and each IBS subtype, exploring novel microbiota-targeted treatments and providing a comprehensive overview of the current state of knowledge.

The Role of Acupuncture on the Gut-Brain-Microbiota Axis in Irritable Bowel Syndrome.

Irritable bowel syndrome (IBS) is a chronic dysfunction of the gastrointestinal tract, commonly characterized by abdominal pain or abdominal discomfort. These symptoms can substantially reduce the quality of life and work productivity of the patients. The exact pathogenesis of IBS remains unclear, as it has become apparent that multiple pathways are activated in the condition, including inflammation, immunology, neurology and psychology. Recent evidence has shown that symptoms in IBS are related to the dysfunction of the nervous system, particularly the viscerosomatic pathway, through immune-to-brain communication. The potential link between brain-gut relationships is gut microbiota. The management of IBS mostly focuses on symptomatically treating the patients. There are a wide range of standard treatments, including pharmacological to psychological interventions which are effective in some patients. Therefore, a combination of therapies including both standard and complimentary treatments, including Traditional Chinese Medicine (TCM) such as acupuncture, have been used in treating IBS patients. Several in vivo and clinical studies have demonstrated the efficacy of acupuncture in treating IBS. Increasing attention has been paid to research regarding the action mechanisms of acupuncture for IBS. This paper summarizes and discusses the possible mechanisms associated with acupuncture on the pathophysiology of IBS, including gastrointestinal (GI) motility, visceral hypersensitivity, the immune system, neurotransmitters, and the brain-gut axis. The results fromin vivo and clinical studies have been included. In addition, the effects of acupuncture on gut microbiota in IBS are included and any contradictory findings are deliberated.

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.

Effect of inulin in the treatment of irritable bowel syndrome with constipation (Review).

At present, irritable bowel syndrome (IBS) is a common medical problem all over the world that implies considerable social burden and high costs. Considering the different pathophysiological pathways, unitary management for IBS is not possible. Of the therapeutic approaches that have been proposed so far, only a few have been demonstrated to have beneficial effects in IBS patients. The implication of gut microbiota in IBS is obvious, similarly to the therapeutic effect of pro-/prebiotics, which is reflected by the latest publications. The intake of inulin seems to regulate the bowel peristalsis and colonic transit, the consistency and frequency of the stools, as it changes the composition of gut microbiota. The beneficial effect of inulin in patients with IBS-constipation form (IBS-C) is obvious, but still, more randomized controlled clinical trials involving large samples of patients are needed in order to provide more evidence.

A Review of Microbiota and Irritable Bowel Syndrome: Future in Therapies

Irritable bowel syndrome (IBS), one of the most frequent digestive disorders, is characterized by chronic and recurrent abdominal pain and altered bowel habit. The origin seems to be multifactorial and is still not well defined for the different subtypes. Genetic, epigenetic and sex-related modifications of the functioning of the nervous and immune-endocrine supersystems and regulation of brain-gut physiology and bile acid production and absorption are certainly involved. Acquired predisposition may act in conjunction with infectious, toxic, dietary and life event-related factors to enhance epithelial permeability and elicit mucosal microinflammation, immune activation and dysbiosis. Notably, strong evidence supports the role of bacterial, viral and parasitic infections in triggering IBS, and targeting microbiota seems promising in view of the positive response to microbiota-related therapies in some patients. However, the lack of highly predictive diagnostic biomarkers and the complexity and heterogeneity of IBS patients make management difficult and unsatisfactory in many cases, reducing patient health-related quality of life and increasing the sanitary burden. This article reviews specific alterations and interventions targeting the gut microbiota in IBS, including prebiotics, probiotics, synbiotics, non-absorbable antibiotics, diets, fecal transplantation and other potential future approaches useful for the diagnosis, prevention and treatment of IBS.

Irritable bowel syndrome: a gut microbiota-related disorder?

Irritable bowel syndrome (IBS) is one of the most common gastrointestinal (GI) disorders. Despite its prevalence, the pathophysiology of IBS is not well understood although multiple peripheral and central factors are implicated. Recent studies suggest a role for alterations in gut microbiota in IBS. Significant advances in next-generation sequencing technology and bioinformatics and the declining cost have now allowed us to better investigate the role of gut microbiota in IBS. In the following review, we propose gut microbiota as a unifying factor in the pathophysiology of IBS. We first describe how gut microbiota can be influenced by factors predisposing individuals to IBS such as host genetics, stress, diet, antibiotics, and early life experiences. We then highlight the known effects of gut microbiota on mechanisms implicated in the pathophysiology of IBS including disrupted gut brain axis (GBA), visceral hypersensitivity (VH), altered GI motility, epithelial barrier dysfunction, and immune activation. While there are several gaps in the field that preclude us from connecting the dots to establish causation, we hope this overview will allow us to identify and fill in the voids.

Microbiome, antibiotics and irritable bowel syndrome.

Irritable bowel syndrome (IBS) is the most prevalent functional gastrointestinal (GI) disorder. Increasing evidence implicates the GI microbiota in IBS pathogenesis and its modulation represents an emerging therapeutic strategy. Original and review articles were identified through selective searches performed on PubMed and Google Scholar. The role of gut microbiota in IBS is supported by evidence from animal and human studies. Randomized controlled trials demonstrate efficacy of the non-systemic antibiotic rifaximin in reducing IBS symptoms. Existing studies on microbiota alterations are often inconsistent and limited by the heterogeneity of IBS. The exact mechanism of rifaximin remains to be elucidated. Identifying predictors of response to rifaximin and treatment strategies for symptom recurrence are important clinical questions. High-throughput molecular methods are leading to rapid advances in our understanding of GI microbiota in IBS AREAS TIMELY FOR DEVELOPING RESEARCH: Future well designed longitudinal studies are required to identify characteristic microbial signatures and potential biomarkers to identify therapeutic targets and predict clinical response.

Role of Omega-3 Fatty Acids in Irritable Bowel Syndrome (IBS)

Background: Dietary supplementation with Omega-3 (?-3) fatty acids (FAs) has been demonstrated to elicit several effects ranging from decrease in blood pressure, anti-arrhythmic effect and decrease in inflammation in inflammatory bowel disease, asthma and rheumatoid arthritis. Irritable bowel syndrome (IBS) is a chronic disorder characterized by abdominal pain and irregular bowel habit. It is associated with visceral hypersensitivity, increased mucosal permeability and a low-grade mucosal inflammation. Commercially available omega (?)-3 polyunsaturated fatty acids (PUFA) are being prescribed as empirical treatment for many chronic ailments including IBS. Aim: To examine literature available support use of ?-3 PUFA in IBS. Methods: We conducted a search using Omega 3 fatty acids supplementation on the PubMed, Scopus, and databases (e.g. MEDLINE, CINAHL, EMBASE, and Science Citation Index Expanded) from 1966 to December, 2015. Result: The gut microbiota in IBS is associated with an imbalance of Firmicutes/Bacteroidetes ratio. This imbalance has an impact on gas and metabolite production such as short chain fatty acids. Omega-3 FAs are anti-inflammatory, while ?-6 FAs are proinflammatory. Conclusion: The benefit of ?-3 FAs for IBS requires more clarification by prospective studies. Current claims of long chain PUFA supplementation in IBS should be viewed with caution

The Lactulose Breath Test in Irritable Bowel Syndrome: Is It All Hot Air?

The microbial ecosystem that occupies the human intestine is essential for the maintenance of health. An intricate relationship exists between the gut microbiome, the central nervous system, the neuroimmune and neuroendocrine systems, the autonomic nervous system, and the enteric nervous system, the interplay of which is responsible for the effective control of the gut by the higher centers. The development of new techniques that enable better characterization of gut bacteria has noticeably increased interest how the human microbiome affects the development of disease, particularly so in the pathophysiology of functional gastrointestinal disorders, where epidemiological studies have long-linked acute gut infection with the development of chronic functional symptoms. Up to 30 % of patients develop irritable bowel syndrome (IBS) after suffering from a gastrointestinal infection, and 40 % describe symptomatic benefit from antibiotic therapy [1]. IBS has also been associated with altered diversity and composition of gut bacteria [2]. Although the exact mechanisms remain poorly defined, the gut microbiome is firmly associated with IBS pathogenesis. Given the presumed pathogenic role of the gut microbiota in IBS, its manipulation is now a ‘‘hot’’ topic in management, from the addition of ‘‘good bacteria’’ via probiotics, the promotion of ‘‘good bacteria’’ via prebiotics, the change of bacterial populations by antibiotics, and the replacement of bacteria via fecal microbiota transfer. Antibiotics have received the most attention since they are a major therapeutic tool in treating small intestinal bacterial overgrowth (SIBO), postulated to be an important link between gut bacteria and IBS. The small bowel normally contains only a fraction of the bacteria present in the large bowel (10 4 ‐10 8 vs. 10 9 ‐10 12 )[ 3]. SIBO, defined as an excess of colonic-type bacteria in the small bowel, is often diagnosed in patients with small bowel abnormalities such as altered anatomy, motility, or flow resulting in stasis, enhancing bacterial proliferation. While SIBO provides an attractive (and potentially treatable) cause for the symptoms of IBS, in reality diagnosing SIBO in IBS patients who have normal anatomy is fraught with controversy.

Microbiota, gastrointestinal infections, low-grade inflammation, and antibiotic therapy in irritable bowel syndrome (IBS): an evidence-based review

BackgroundPost-infectious irritable bowel syndrome (PI-IBS) prevalence, small intestinal bacterial overgrowth (SIBO), altered microbiota, low-grade inflammation, and antibiotic therapy in IBS are all controversial issues. AimsTo conduct an evidence-based review of these factors. MethodsA review of the literature was carried out up to July 2012, with the inclusion of additional articles as far as August 2013, all of which were analyzed through the Oxford Centre for Evidence-Based Medicine (OCEBM) system. Results1. There is greater SIBO probability in IBS when breath tests are performed, but prevalence varies widely (2-84%). 2. The gut microbiota in individuals with IBS is different from that in healthy subjects, but a common characteristic present in all the patients has not been established. 3. The incidence and prevalence of PI-IBS varies from 9-10% and 3-17%, respectively, and the latter decreases over time. Bacterial etiology is the most frequent but post-viral and parasitic cases have been reported. 4. A sub-group of patients has increased enterochromaffin cells, intraepithelial lymphocytes, and mast cells in the intestinal mucosa, but no differences between PI-IBS and non PI-IBS have been determined. 5. Methanogenic microbiota has been associated with IBS with constipation. 6. Rifaximin at doses of 400mg TID/10 days or 550mg TID/14 days is an effective treatment for the majority of overall symptoms and abdominal bloating in IBS. Retreatment effectiveness appears to be similar to that of the first cycle. ConclusionsFurther studies are required to determine the nature of the gut microbiota in IBS and the differences in low-grade inflammation between PI-IBS and non PI-IBS. Rifaximin has shown itself to be an effective treatment for IBS, regardless of prior factors.

Review article: evidence for the role of gut microbiota in irritable bowel syndrome and its potential influence on therapeutic targets

Irritable bowel syndrome (IBS) is a prevalent gastrointestinal disease with a substantial social and economic burden. Treatment options remain limited and research on the aetiology and pathophysiology of this multifactorial disease is ongoing. To discuss the potential role of gut microbiota in the pathophysiology of IBS and to identify possible interactions with pathophysiologic targets in IBS. Articles were identified via a PubMed database search ['irritable bowel syndrome' AND (anti-bacterial OR antibiotic OR flora OR microbiota OR microflora OR probiotic)]. English-language articles were screened for relevance. Full review of publications for the relevant studies was conducted, including additional publications that were identified from individual article reference lists. The role of gut microbiota in IBS is supported by varying lines of evidence from animal and human studies. For example, post-infectious IBS in humans is well documented. In addition, certain probiotics and nonsystemic antibiotics appear to be efficacious in the treatment of IBS. Mechanisms involved in improving IBS symptoms likely go beyond mere changes in the composition of the gut microbiota, and accumulating animal data support the interplay of microbiota with other IBS targets, such as the gut-brain axis, visceral hypersensitivity, mucosal inflammation and motility. The role of the gut microbiota is still being elucidated; however, it appears to be one of several important factors that contributes to the aetiology and pathophysiology of the irritable bowel syndrome.

Irritable bowel syndrome: a microbiome-gut-brain axis disorder?

Irritable bowel syndrome (IBS) is an extremely prevalent but poorly understood gastrointestinal disorder. Consequently, there are no clear diagnostic markers to help diagnose the disorder and treatment options are limited to management of the symptoms. The concept of a dysregulated gut-brain axis has been adopted as a suitable model for the disorder. The gut microbiome may play an important role in the onset and exacerbation of symptoms in the disorder and has been extensively studied in this context. Although a causal role cannot yet be inferred from the clinical studies which have attempted to characterise the gut microbiota in IBS, they do confirm alterations in both community stability and diversity. Moreover, it has been reliably demonstrated that manipulation of the microbiota can influence the key symptoms, including abdominal pain and bowel habit, and other prominent features of IBS. A variety of strategies have been taken to study these interactions, including probiotics, antibiotics, faecal transplantations and the use of germ-free animals. There are clear mechanisms through which the microbiota can produce these effects, both humoral and neural. Taken together, these findings firmly establish the microbiota as a critical node in the gut-brain axis and one which is amenable to therapeutic interventions.