Conflict of interest: There is no conflict of interest to be declared.
Effect of probiotic bacteria on the intestinal microbiota in irritable bowel syndrome
Article first published online: 23 SEP 2013
© 2013 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd
Journal of Gastroenterology and Hepatology
Volume 28, Issue 10, pages 1624–1631, October 2013
How to Cite
Ng, S. C., Lam, E. F. C., Lam, T. T. Y., Chan, Y., Law, W., Tse, P. C. H., Kamm, M. A., Sung, J. J. Y., Chan, F. K. L. and Wu, J. C. Y. (2013), Effect of probiotic bacteria on the intestinal microbiota in irritable bowel syndrome. Journal of Gastroenterology and Hepatology, 28: 1624–1631. doi: 10.1111/jgh.12306
Authors' contribution: SC Ng (study concept and design; patient recruitment, and drafting of manuscript), FC Lam (Sample collection and DNA extraction), TT Lam (data analysis, revision of manuscript), WT Law and CH Tse (DNA extraction); MA Kamm, KL Chan and JY Sung (revision of manuscript); CY Wu (study supervision; revision of manuscript).
- Issue published online: 23 SEP 2013
- Article first published online: 23 SEP 2013
- Accepted manuscript online: 25 JUN 2013 08:08PM EST
- Manuscript Accepted: 12 JUN 2013
- intestinal microbiota;
Background and Aim
In irritable bowel syndrome (IBS), the gut microbiota may be altered. Probiotic bacteria appear to be therapeutically effective. We characterized the mucosa-associated microbiota, and determined the clinical and microbiological effects of orally administered probiotic bacteria, in patients with IBS.
Mucosal microbiota from rectal biopsies of IBS patients and controls were assessed on the V1 and V2 variable regions of the 16S ribosomal RNA gene amplified using 454 pyrosequencing. Clinical symptoms and changes in mucosal microbiota were assessed in IBS patients before and after 4 weeks of treatment with probiotic mix VSL#3.
Ten IBS subjects (eight female; mean age 46 years) were included. At week 4 of probiotic therapy, six patients showed symptom improvement on global symptom assessment compared with baseline (P = 0.031). Before therapy, intestinal microbiota of IBS subjects differed significantly from that of healthy controls, with less diversity and evenness than controls (n = 9; P < 0.05), increased abundance of Bacteroidetes (P = 0.014) and Synegitestes (P = 0.017), and reduced abundance of Actinobacteria (P = 0.004). The classes Flavobacteria (P = 0.028) and Epsilonproteobacteria (P = 0.017) were less enriched in IBS. Abundance differences were largely consistent from the phylum to genus level. Probiotic treatment in IBS patients was associated with a significant reduction of the genus Bacteroides (all taxonomy levels; P < 0.05) to levels similar to that of controls.
In this pilot study, global and deep molecular analysis demonstrates an altered mucosal microbiota composition in IBS. Probiotic leads to detectable changes in the microbiota. These effects of probiotic bacteria may contribute to their therapeutic benefit.