Inflammatory bowel disease, intestinal microflora, prebiotics and probiotics

Inflammatory bowel disease (IBD) is a group of intestinal conditions characterized by chronic relapsing course of uncontrolled inflammation within the gastrointestinal tract. The two main types of IBD are ulcerative colitis (UC) and Crohn’s disease (CD). Both genetic and environmental factors are involved in etiopathogenesis. According to most recent theories, IBD is probably a consequence of abnormal mucosal immune response to antigens of gut bacterial microflora in geneticaly susceptable individuals. If tolerance to commensal bacteria is lost, an immune response may be elucidated against non-pathogenic bacteria, leading to increased production of inflammatory cytokines and chemokines. Consequently different subsets of inflammatory cells are activated. Growing knowledge about implication of gut microflora into the pathogenesis of IBD encouraged scientific word to search for new therapeutic strategies concentrated on changing the microenvironmental factors. Nutritional therapy has been advocated in CD patients, especially for children and adolescents. The rationale behind prebiotic use is to elevate the populations of certain beneficial bacteria and thereby quantitatively changing the composition of microflora. Although several prebiotic compounds possess promising properties to have beneficial effect on IBD, only few of them (Plantago ovata, germinated barley foodstuff) have been clinically tested. Multiple mechanisms of action have been suggested to explain the effect of probiotics in IBD. A great number of basic, animal model and human studies have revealed the great potential of probiotic use in treatment of IBD patients. However, clinical use of probiotics has been proved effective only in a therapy of pouchitis and maintenance of remission in ulcerative colitis, while their effectiveness in a therapy of Crohn’s disease is not firmly proved.