P-087 YI Review of Dietary Fiber and Gut Health

Abstract

BACKGROUND: Dietary fibers reach the distal intestines relatively intact and impart benefits to the intestinal epithelium and the gut microbial ecosystem. 1-11 Recently, researchers around the world have been investigating dietary fiber as a potential therapy for inflammatory bowel diseases (IBD).8,12-20 However, individuals with IBD sometimes needlessly avoid high fiber foods, because they assume dietary fiber is inflammatory. 21 The aim of this literature review was to investigate the rationale for testing dietary fiber as a therapeutic intervention for IBD and to describe what is known about dietary fiber and gut health in the context of the disorders. METHOD(S): Reports of fiber-related studies were identified by searching in PubMed on keywords "inflammatory bowel disease" and "fiber." Additional fiber-related studies were identified by requesting automatic alerts from the National Center for Biotechnology Information as articles on the topic of "Crohn's disease and diet" were published. RESULT(S): The results of this literature review include evidence for the ability of dietary fiber to improve barrier function, 22 down-regulate the NFkB pathway, 23 and decrease tumor necrosis factor alpha23 (TNF-alpha) levels23 through production of short chain fatty acids as metabolites of bacterial fermentation. 1,24 Dietary fibers can also function as a natural pre-biotic, promoting proliferation of beneficial, saccharolytic commensal bacteria, 19,24 and providing colonization resistance against invading pathogens. 19,24,25 Other findings include the high water-holding capacity of dietary fiber that can promote the optimal ratio of water to waterholding- capacity that may help resolve diarrhea during a flare. 26-30 Increased consumption of dietary fiber can be well tolerated in patients with IBD. 16 Randomized controlled trials indicate that certain dietary fibers alone can be of therapeutic benefit, 31,32 or those as part of symbiotic regimens can improve quality of life, 33 and induce remission28 in IBD. CONCLUSION(S): Thus inclusion of dietary fiber in the diet may help an individual to experience improved health-related quality of life even before the metabolic benefits of fiber can manifest. In agreement with earlier reviews on the topic, 34 our work indicates that direct and indirect biologic effects of dietary fiber may have important implications in the prevention and treatment of IBD.