Lay Summary

Proposal No. IBD-0166R
Principal Investigator:   James O. Lindsay, BM BCh, Ph.D.
Applicant Organization:  King's College London (United Kingdom)
Project Title:  Fructo-oligosaccharides and Crohn’s disease: a prospective, randomized, double-blind controlled trial
Period of Award:  August 7, 2006 – December 31, 2009

Crohn’s disease is a chronic inflammatory condition of the bowel that leads to a range of complications. Approximately 50% of patients require surgery to remove an affected part of bowel in the first five years of their disease. Current medical treatments that aim to control the disease and prevent recurrence after surgery by suppressing the immune system are associated with a wide range of side effects. Recent research into the cause of Crohn’s disease has focused on the relationship between the bacteria in the bowel and the gut immune system. There is strong evidence that certain strains of these bacteria prolong the inflammation associated with Crohn’s disease. However, it has been discovered recently that bacteria such as bifidobacteria may reduce bowel inflammation and increase protective mechanisms in the bowel lining. Also, studies have shown differences in the numbers and types of bacteria between healthy people and patients with Crohn’s disease, as well as between patients with active and inactive disease. This has led to attempts to modify the gut bacterial balance as a treatment for Crohn’s disease.

We will investigate the beneficial effect of fructo-oligosaccharide (FOS), a type of carbohydrate, as a novel strategy for increasing bifidobacteria within the bowel. FOS is resistant to digestion by humans, but can be fermented by bifidobacteria. Supplementing the diet with FOS leads to an increase in the number of bifidobacteria in the colon of healthy volunteers. We have performed an initial study in ten patients with Crohn’s disease which showed that adding three spoonfuls of FOS to the regular diet each day was well tolerated, led to an increase in the number of bifidobacteria in the stool, increased the production of anti-inflammatory proteins and, most importantly, improved the Crohn’s disease activity.

In view of these exciting, preliminary results, we will investigate the beneficial effects of this new dietary therapy for patients with moderately active Crohn’s disease in a four week, placebo-controlled trial. In order to detect any benefit of this therapy, we will study 110 patients. During the trial we will assess disease activity, side effects, quality of life, changes in bacterial numbers within the gut and the effect of FOS on the bowel immune system. We will follow up patients for a further eight weeks to measure the duration of benefit.

This trial has been designed to determine whether FOS lead to a significant improvement in Crohn’s disease compared to placebo, and to investigate its effects on both the bacteria in the colon and the gut immune system. This therapy has none of the side effects of traditional Crohn’s disease drugs and would therefore represent a major advance in the treatment of this chronic disease.