Continuing Medical Education Questions: June 2021 (original) (raw)

The Role of Gut-Microbiota in the Pathophysiology and Therapy of Irritable Bowel Syndrome: A Systematic Review

Cureus

Irritable Bowel Syndrome (IBS) is one of the most prevalent chronic gastrointestinal diseases, which is characterized by recurrent abdominal pain and altered bowel habits. The pathophysiological mechanisms are not completely clear for IBS, multiple factors such as genetic, psychosocial, environmental, visceral hypersensitivity, low-grade inflammation, gastrointestinal motility changes, food components, and intestinal microbiota are thought to play a role in the disease process of IBS. The rapid progression of recent microbiome research using advanced microbiological technologies has shed light on dysbiosis related to the pathophysiology of IBS. We used PubMed, PubMed Central, and Medline as our primary databases to search for articles using keywords and medical subject heading (MeSH) keywords on April 30, 2022, to render a total of 4062 articles. Then, a total of 10 articles were selected following a quality assessment. Despite the variable findings in different studies, most studies have concluded that IBS patients have a reduction in bacterial diversity and an increase in the temporal instability of the microbiota. IBS is known as a stress disorder, and the gut-microbiome-brain axis has been associated with the pathogenesis of the disease. Additionally, the potential of dietary manipulation of gut microbiota and the use of probiotics, prebiotics, and synbiotics in the treatment of IBS has been studied in recent years and shown promising results. We concluded that the gut microbiome plays a substantial role in the pathophysiology of IBS.

Fecal Microbiome Diversity in Irritable Bowel Syndrome (IBS) Clinical Subtypes Citation

Irritable bowel syndrome (IBS) is a functional gut brain gastrointestinal (GI) disorder, typically accompanied by constipation or diarrhea, usually without any organic evidence. The prevalence of IBS is rather high of about 10-15% (10, 1 % according to Rome III and 4, 1% according to Rome IV, Enck P. et al 2016, Sperber A.D. et al 2020, Black C.J. et al 2020) in the working population. Quality of life in patients with IBS is reduced and therefore a major obstacle to the normal physical and social wellbeing. In intensified clinical research worldwide new pathogenic mechanisms of IBS are suggested, Arch Clin Biomed Res 2021; 5 (1): 125-136

The putative role of the intestinal microbiota in the irritable bowel syndrome

Digestive and Liver Disease, 2009

The irritable bowel syndrome (IBS) is a chronic abdominal symptom complex that is heterogeneous in terms of its clinical presentation and underlying pathophysiology and pathogenesis. It is now established that enteric infection can trigger the syndrome in at least a subset of patients. In addition, there is growing evidence of low grade inflammation and immune activation in the distal bowel of some IBS patients. These observations now prompt the question as to what maintains gut dysfunction in these patients. The intestinal microbiota influences a broad array of host organs that include the gut and the brain, and is an important determinant of normal function in these systems. Disruption of the delicate balance between the host and its intestinal microbiota (termed dysbiosis) results in changes in the mucosal immune system that range from overt inflammation as seen in Crohn's Disease, to low grade inflammation without tissue injury, as seen in a subset of IBS patients. Under experimental conditions, disruption of the microbiota also produces changes in gut sensory-motor function and immune activity. Thus, dysbiosis induced by infection, dietary change or drugs such as antibiotics could produce low grade inflammation and chronic gut dysfunction, reminiscent of that seen in IBS. Fluctuations in gut physiology destabilize the habitat of commensal bacteria and provide a basis for chronic dysbiosis. Recent observations in animal models that changes in gut flora influence behavior provide a basis for a novel unifying hypothesis that accommodates both gut dysfunction and behavioral changes that characterize many IBS patients. This hypothesis states that dysbiosis exists in at least a subset of IBS patients, as a result of infection, dietary change or drugs and contributes to gut inflammatory and functional change in addition to psychiatric co-morbidity.

Fecal Microbiome Diversity in Irritable Bowel Syndrome (IBS) Clinical Subtypes

Clinical & Biomedical Research, 2021

Irritable bowel syndrome (IBS) is a functional gut brain gastrointestinal (GI) disorder, typically accompanied by constipation or diarrhea, usually without any organic evidence. The prevalence of IBS is rather high of about 10-15% (10, 1 % according to Rome III and 4, 1% according to Rome IV, Enck P. et al 2016, Sperber A.D. et al 2020, Black C.J. et al 2020) in the working population. Quality of life in patients with IBS is reduced and therefore a major obstacle to the normal physical and social wellbeing. In intensified clinical research worldwide new pathogenic mechanisms of IBS are suggested, including intestinal dysbiois one of the critical contributing factors to onset or further development of IBS. Intestinal microbiome represents a real ecosystem of microorganisms and human GI tract lining cells. The diversity and composition of the GI microbiome may differ significantly inter- and intra-individually, depending on sex, age or physiological conditions (pregnancy, disease, etc...

A265 Temporal Dynamics of Symptoms and Gut Microbiota in Episodes of Irritable Bowel Syndrome

Journal of the Canadian Association of Gastroenterology

Background Irritable bowel syndrome (IBS) is a disorder of gut-brain axis that manifests with chronic abdominal pain, altered bowel habits, and frequent psychiatric comorbidities. Despite mounting evidence showing gut microbiota composition and associated metabolites being altered in IBS, the mechanisms by which they drive the symptoms are unclear. We have previously shown that several IBS symptoms co-occur, that their severity vary among IBS subtypes (10.1093/jcag/gwab049.050), and that several bacterial taxa are differentially modulated during periods of symptom flares and remission. Here we investigate whether the changes in gut microbiome and bacterial metabolites are linked to symptom occurrence and severity. Purpose To investigate temporal associations of IBS symptoms with gut microbiota profiles and metabolites. Method 16S rRNA gene sequencing was performed on stool samples of 28 IBS patients (IBS-D n=20, IBS-C n=8) and 10 healthy controls (HC), collected weekly over a period...

IBS and Microbiota

Irritable bowel syndrome (IBS) is a heterogeneous functional disorder with a multifactorial etiology that involves the interplay of both host and environmental factors. Among environmental factors relevant for IBS etiology, the diet stands out given that the majority of IBS patients report their symptoms to be triggered by meals or specifi c foods. The diet provides substrates for microbial fermentation, and, as the composition of the intestinal microbiota is disturbed in IBS patients, the link between diet, microbiota composition, and microbial fermentation products might have an essential role in IBS etiology. In this review, we summarize current evidence regarding the impact of diet and the intestinal microbiota on IBS symptoms, as well as the reported interactions between diet and the microbiota composition. On the basis of the existing data, we suggest pathways (mechanisms) by which diet components, via the microbial fermentation, could trigger IBS symptoms. Finally, this review provides recommendations for future studies that would enable elucidation of the role of diet and microbiota and how these factors may be (inter)related in the pathophysiology of IBS.

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

Frontiers in Microbiology

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.

The gut microbiome and irritable bowel syndrome: State of art review

Arab journal of gastroenterology : the official publication of the Pan-Arab Association of Gastroenterology, 2018

Irritable bowel syndrome (IBS) is a functional disorder of the gastrointestinal tract, the physiology of which is not very well understood. There are multiple factors and pathways involved in pathogenesis of this entity. Among all, dysmotility, dysregulation of the brain-gut axis, altered intestinal microbiota and visceral hypersensitivity play a major role. Over the last years, research has shown that the type of gut microbiome present in an individual plays a significant role in the pathophysiology of IBS. Multiple studies have consistently shown that subjects diagnosed with IBS have disruption in gut microbiota balance. It has been established that host immune system and its interaction with metabolic products of gut microbiota play an important role in the gastrointestinal tract. Therefore, probiotics, prebiotics and antibiotics have shown some promising results in managing IBS symptoms via modulating the interaction between the above. This paper discusses the various factors in...