Scand J Gastroenterol. 2015 Nov 23:1-10. [Epub ahead of print]

Differences of microbiota in small bowel and faeces between irritable bowel syndrome patients and healthy subjects.

Chung CS1,2,3, Chang PF4,5, Liao CH6, Lee TH1, Chen Y7, Lee YC8, Wu MS8, Wang HP8, Ni YH9.


Author information

1a Department of Internal Medicine , Far Eastern Memorial Hospital , New Taipei City , Taiwan ;
2b College of Medicine , Fu Jen Catholic University , New Taipei City , Taiwan ;
3c Taiwan Association for the Study of Small Intestinal Diseases (TASSID) , New Taipei City , Taiwan ;
4d Department of Pediatrics , Far Eastern Memorial Hospital , New Taipei City , Taiwan ;
5e Department of Healthcare Administration , Oriental Institute of Technology , New Taipei City , Taiwan ;
6f Department of Infectious Diseases , Far Eastern Memorial Hospital , New Taipei City , Taiwan ;
7g Department of Surgery , Far Eastern Memorial Hospital , New Taipei City , Taiwan ;
8h Department of Internal Medicine , National Taiwan University Hospital , Taipei , Taiwan ;
9i Department of Pediatrics , National Taiwan University Hospital , Taipei , Taiwan.

Abstract

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).