Altered microbiota predicts development of pouchitis

Last Updated: 2016-10-12

By Reuters Staff

NEW YORK (Reuters Health) - Decreases in enteric microbial diversity predict the development of pouchitis in patients with ulcerative colitis (UC), researchers from Israel report.

About 30% of UC patients undergo surgery due to refractory disease or dysplasia/colon cancer, most commonly restorative proctocolectomy and ileal pouch anal-anastomosis. Up to 60% of these patients develop pouchitis, according to the researchers.

Dr. Iris Dotan from Tel Aviv Sourasky Medical Center and colleagues explored whether microbial alterations are predictive of pouch inflammation in a prospective study of 20 patients, all at least one year post-ileocolostomy and with a normal pouch at baseline.

Thirteen patients continued to have normal pouches throughout follow-up, whereas seven developed pouchitis within a year of study recruitment, according to a report online September 9th in the Journal of Crohn's and Colitis.

Microbial diversity was significantly increased in the group that maintained normal pouches compared with the group that eventually developed pouchitis. This difference was already apparent at the time of study entry, even when there was no evidence of pouch inflammation.

The presence of Ruminococcus was significantly increased in patients who remained free of pouchitis. This genus provides important growth substrates that maintain intestinal mucosal integrity, according to the report.

Even among patients whose pouches remained free of inflammation, microbial diversity was significantly lower with a pouch age <1 year than with a pouch age >1 year, and microbial diversity increased steadily during 3 years of follow-up.

"The findings of this study demonstrate that reduced pouch microbial diversity and possibly also reductions in specific bacterial groups may predispose patients who underwent ileal pouch anal-anastomosis to develop pouchitis," the researchers conclude. "More importantly, finding these changes in a 'normal' pouch may predict impending pouchitis. This may necessitate different preventative therapy, such as the use of probiotics or immunomodulators at an early stage."

"Recently, fecal microbial transplantation has demonstrated significant efficacy in increasing microbial diversity in patients with recurrent Clostridium difficile infection," they add. "Potentially, this therapy may be tested in patients with a pouch and evidence for decreased microbial diversity, in order to reduce the considerable morbidity associated with pouchitis."

Dr. Dotan did not respond to a request for comments.

SOURCE: http://bit.ly/2cIOtkU

J Crohns Colitis 2016.