Evidence of altered mucosa-associated and fecal microbiota composition in patients with Irritable Bowel Syndrome

Abstract

Altered bacterial composition and small intestinal bacterial overgrowth (SiBo) may be associated with irritable bowel syndrome (IBS). This study aimed to determine the fecal and mucosa-associated bacterial composition along the gastrointestinal (GI) tract and to assess SIBO in IBS. Bacterial composition of feces, and mucosa of the duodenum and sigmoid colon was determined by 16S rRNAamplicon-sequencing. SIBO was evaluated by bacterial culture of duodenal aspirate, glucose and lactulose breath tests. Mucosal antibacterial gene expression was assessed by PCR Array. The bacterial profiles of feces and the mucosa of sigmoid colon, but not duodenum, differed between IBS patients (n = 17) and HS (n = 20). The IBS specific bacterial profiles were linked to the colonic antibacterial gene expression. Fecal bacterial profile differed between IBS subtypes, while the mucosa-associated bacterial profile was associated with IBS symptom severity and breath tests results at baseline (H 2 and/or cH 4 ≥ 15 ppm). The prevalence of SIBO was similar between IBS patients and HS. This study demonstrates that alterations in the bacterial composition of the sigmoid colon of iBS patients were linked to symptoms and immune activation. While breath tests reflected the mucosa-associated bacterial composition, there was no evidence for high prevalence of SIBO or small intestinal bacterial alterations in IBS.

Microbial and metabolomic profiles in correlation with depression and anxiety co-morbidities in diarrhoea-predominant IBS patients

“…Vast studies demonstrated that Bifidobacterium and Lactobacillus were less abundant in IBS-D, whereas Clostridium, Escherichia coli and Enterobacter were often increased [19,20,[24][25][26]. Faecalibacterium (or F. prausnitzii) abundance in IBS increased in some studies [27], but constant or decreased in others [24]. However, a recent meta-analysis that included 17 studies argued that species-specific alterations of gut microbiota were different between IBS patients from China and other regions [25].…”

“…However, a recent meta-analysis that included 17 studies argued that species-specific alterations of gut microbiota were different between IBS patients from China and other regions [25]. Differentiation of microbial composition also existed among different IBS sub-categories (especially between IBS-D and constipation-predominant IBS), probably due to distinct manifestations of IBS bowel motility [24,27,28]. Here we found Faecalibacterium, Subdoligranulum and Eubacterium rectale group, all capable of producing butyrate [29], were depleted in IBS-D faecal samples.…”

P2X3 Receptor in Primary Afferent Neurons Mediates the Relief of Visceral Hypersensitivity by Electroacupuncture in an Irritable Bowel Syndrome Rat Model

“…Irritable bowel syndrome is a chronic functional bowel disorder [ 1 , 2 ]. Visceral hypersensitivity is one of the main pathophysiological mechanisms of IBS [ 3 , 4 ].…”

Tryptophan Metabolites Along the Microbiota-Gut-Brain Axis: An Interkingdom Communication System Influencing the Gut in Health and Disease

“…Unbalanced compositions of the microflora harbouring the human gut have been associated with numerous diseases, including gastrointestinal disorders. [244][245][246][247] Accordingly, data obtained from preclinical and clinical studies show that the pathogenesis of both IBS and IBD may, at least in part, depend on alterations of the saprophytic microflora, although a clear-cut demonstration of this correlation for both diseases has not yet been given. 8,248 Both in IBS and IBD, changes in the microbial community and in its metabolites participate in dysfunctions of the epithelial, immune, and neuronal gut compartments.…”