Nutritional and Physiological Studies on Resistant Starch and Dietary Fiber

Summary : Previously, the physiological effects of dietary fiber in the small intestine have been discussed mainly on the basis of the interaction of dietary fiber with simultaneously ingested nutrients in the gastrointestinal tract, and only a limited number of studies have focused on events in the gastrointestinal tract itself. This review covers the results of analyses of small-intestinal goblet cell responses and mucin secretion during dietary fiber intake, based mainly on the bulk and viscosity of the dietary fiber. Mucin from the small intestine acts as an endogenous fiber that underpins the symbiotic relationship between the host and intestinal bacteria via short-chain fatty acids, a metabolic product of fermentation. Finally, the validity of the current Prosky digestion-based dietary fiber quantification method to estimate the gastrointestinal kinetics of resistant starch and diges-tion-resistant dextrin derivatives is discussed. These have recently attracted attention as new dietary fiber mate-rials in addition to classic dietary fibers derived from plant cell walls.