Dietary Fibers and Their Fermented Short-Chain Fatty Acids in Prevention of Human Diseases.

Many studies show that daily consumption of high-fiber diet is associated with a reduced risk of developing kidney stones, inflammatory disease, colon cancer and other malignancies, obesity, type II diabetes, and cardiovascular disease. Dietary fibers are non-digestible polysaccharides that are composed of complex carbohydrates. Based on their relative solubility in water, dietary fibers can be divided into insoluble and soluble forms. An important property of insoluble fibers is their ability to bind with carcinogens, mutagens, and other toxic chemicals that are formed during digestion of food and eliminate them through the feces. Soluble fibers can often be degraded to short-chain fatty acids, such as butyrate, propionate, and acetate by microbial fermentation. This review discusses mechanisms of action of fibers and their beneficial effects on the GI tract as well as on other organs. Among short-chain fatty acids, butyrate has been most extensively studied and the effects of sodium butyrate on cell culture and animal models are discussed in order to emphasize its potential value in prevention of certain diseases.