ABSTRACT
Nondigestible oligosaccharides (NDO) are carbohydrates that escape digestion/hydrolysis in the stomach and small intestine, but they are fermented by the colonic bacterial flora. Regarding the proposed mechanisms of the influence of NDO on mineral absorption, the effects in the stomach/small intestine are basically different from those in the colon. As discussed above, during digestion of foods various factors may play a role in the interaction with minerals. One of the adverse effects of an increased dietary fiber intake is the decreased availability of minerals and trace elements for absorption. Basically, the mechanisms involved include the possible binding of minerals to dietary fiber during the preabsorption stage. The mechanisms involved probably include the formation of short-chain fatty acids as a consequence of NDO fermentation, which may lower colonic pH and make the minerals more soluble and available for absorption.
