Grant: Operating Grant

Ulcerative colitis (UC) is a chronic relapsing inflammation of the colon ("colitis") affecting around 300 per 100.000 Canadians, the highest in the world. It causes frequent episodes of bloody diarrhea ("flares") with loss of quality of life, employment and continuous use of expensive drugs. The current drug therapies are potentially toxic, as they are mostly directed towards the abnormal immune response. The current theory is that a lack of protective ("probiotic") intestinal bacteria versus disease-inducing bacteria can lead to a flare of UC. Indeed, the ingestion of probiotics has been shown to treat and prevent UC. Non-digestible dietary carbohydrates are fibers that are easy to administer and very inexpensive versus drugs and even probiotics. These fibers stimulate protective bacteria that are already present in the gut whereas these bacteria produce natural products against inflammation. We recently found that a mixture of non-digestible fibers not only reduced colitis in a rat model, but was also able to treat active mild to moderate UC in a small clinical trial. In this grant we will study if the same fiber mixture used in the rats and UC patients also prevent flares that occur despite standard drugs. If these fibers are effective, this inexpensive therapy will then prevent patients to add more potentially toxic drugs or even prevent loss of their colon. There is still a lack of knowledge which bacteria induce (flares of) ulcerative colitis. By using molecular techniques analyzing the many gut bacteria that cannot be cultured plus what they are doing, we expect to identify which bacterial functions are stimulated before and during relapse, and especially what factors are associated with relapse prevention by our fiber mixture in each patient. This knowledge may unravel the cause of (relapses in) UC and could lead to novel (dietary), personalized therapies for this debilitating disorder.