Effects of Butyrate on Colonic Health of Patients With Diarrhoea Predominant IBS and UC in Remission

Short chain fatty acids (mainly butyrate, acetate, and propionate) are produced in the large intestine by bacterial fermentation of undigested carbohydrates, such as dietary fibres. Butyrate is an important energy source of the intestinal epithelium and has a pivotal role in the regulation of epithelial cell proliferation and differentiation, immune function and mucosal protection. Non-digestible carbohydrates (prebiotics) increase the concentrations of colonic butyrate, which has been proposed to be responsible for its beneficial effects. Furthermore, butyrate enemas have been proven to be effective in the treatment of active ulcerative colitis. In the present study, the direct effects of butyrate on inflammation and parameters of colonic defence and mucosal integrity of the distal colon will be studied in 40 patients with diarrhoea predominant IBS (D-IBS) and 40 patients with ulcerative colitis in remission (UCrem) using rectal enemas. These patients groups were chosen because they have a low-grade inflammation in the large intestine, and can therefore be used as a model to study the mechanistic effects of butyrate. The design used to study the effects of butyrate in both patient groups will be a double blind randomized placebo-controlled parallel design.