Related Experiment Video
Updated: Mar 29, 2026

Perturbations of Circulating miRNAs in Irritable Bowel Syndrome Detected Using a Multiplexed High-throughput Gene Expression Platform
Published on: November 30, 2016
Differences of microbiota in small bowel and faeces between irritable bowel syndrome patients and healthy subjects
Chen-Shuan Chung1,2,3, Pi-Feng Chang4,5, Chun-Hsing Liao6
1a Department of Internal Medicine , Far Eastern Memorial Hospital , New Taipei City , Taiwan ;
Objective:
Several studies suggested that colonic microbiota have impacts on irritable bowel syndrome (IBS) patients. However, the knowledge about the association of small intestine (SI) microbiota with IBS is limited. We aimed to investigate the gut microbiota composition of SI and stool in IBS patients.
Materials And Methods:
Biopsies of jejunum mucosa by balloon-assisted enteroscopy and faecal samples from 28 IBS patients and 19 healthy controls were analysed by next-generation sequencing method.
Results:
The three major phyla in SI microbiota of case/control groups were Proteobacteria (32.8/47.7%), Bacteroidetes (25.2/15.3%), and Firmicutes (19.8/11.2%), and those of stool were Bacteroidetes (41.3/45.8%), Firmicutes (40.7/38.2%), and Proteobacteria (15.4/7.1%). Analysis based on the family level, IBS patients had a higher proportion of Veillonellaceae (mean proportion 6.49% versus 2.68%, p = 0.046) in stool than controls. Prevotellaceae was more abundant in IBS patients than in control group (14.27% versus 6.13%, p = 0.023), while Mycobacteriaceae (0.06% versus 0.17%, p = 0.024) and Neisseriaceae (6.40% versus 8.94%, p = 0.038) was less abundant in IBS patients' jejunal mucosa than those in controls. This less abundant jejunal Neisseriaceae was associated with more severe IBS (p = 0.03). The ratio of Firmicutes to Bacteroidetes in the stool of IBS-diarrhoea type patients was approximately three-fold higher, and the ratio of Firmicutes to Actinobacter in SI of IBS-mixed type patients was about nine-fold higher than healthy subjects.
Conclusion:
Higher abundance of colonic Veillonellaceae and SI Prevotellaceae, and lower amount of oral cavity normal flora in proximal SI were found in IBS patients. We may manipulate these bacteria in IBS patients in future studies (ClinicalTrial.gov Number NCT01679730).
Related Concept Videos
Irritable Bowel Syndrome I: Introduction
IBS is a chronic condition that can persist over a long period or recur frequently.
The pathogenesis of IBS involves a complex interplay of the following factors:
Altered...
Microbiota of the Large Intestine
Microbiota of the Stomach and Small Intestine
Functions of the Gut Microbiota
Irritable Bowel Syndrome II: Clinical Features and Diagnostic Evaluation
Irritable Bowel Syndrome (IBS) is classified into subtypes based on the predominant bowel habits as determined by the Bristol Stool Form Scale (BSFS). The subtypes are:
Development of Human Microbiota

