Modification of intestinal flora in the treatment of inflammatory bowel disease

Because the intestinal microflora play an important role in the development of inflammatory bowel disease (IBD), there is currently some interest in the manipulation of the composition of the microflora towards a potentially more remedial community. This review summarizes the clinical and experimental efficacy of the manipulation of microflora by the use of prebiotics, probiotics, synbiotics, and antibiotics in IBD. Prebiotics, defined as nondigestible food ingredients that beneficially affect the host by selectively stimulating the growth or activity of one or a limited number of bacterial species already resident in the colon, can modulate the colonic microbiota by increasing the number of specific bacteria and thus changing the composition of the microbiota. Prebiotics for IBD include lactosucrose, oligofructose, inulin, bran, psyllium, and germinated barley foodstuff (GBF). GBF, which mainly consists of dietary fiber and glutamine-rich protein, is a prebiotic foodstuff for ulcerative colitis. GBF has shown to be converted into a preferential nutrient for colonocytes through Eubacterium and Bifidobacterium and also inactivate nuclear factor kappa B (NFkB). Moreover, it exhibits a potent water-holding capacity and bile-acid binding capacity. Probiotics, which are microbial food supplements that beneficially affect the host by improving the intestinal microbial balance, have been used to change the composition of colonic microbiota. The approaches for IBD include VSL#3, Nissle1917, Clostridium butyricum and Bifidobacterium-fermented milk. Use of Lactococci secreting IL-10 provides excellent results. The combination of prebiotics and probiotics in a synbiotic has not been studied in IBD but is promising. The use of antibiotics continues to be of interest. Although these strategies hold great promise and appear to be useful in some settings, more clinical study is needed to firmly establish the relevance of these therapies.