[Effect of bulk materials on the upper intestinal tract].

Dietary fibers comprise a very heterogenous group of indigestible plant compounds. Whereas they exert only little effects on the recovery of the digestible parts of a meal they can modify various digestive processes. Most important seems to be the ability to inhibit digestion and absorption of carbohydrates, which enables better treatment of diabetics. The observation that serum cholesterol can be decreased by certain dietary fibers finds special interest also because of the possible reduction of risk for developing atherosclerosis. The various effects depend upon the physicochemical properties of the different fibers: they comprise the ability to bind water and organic substances, viscosity and cationic-exchange.