2023 Volume 76 Issue 6 Pages 363-369
Non-digestible oligosaccharides are defined as “carbohydrates that are hardly digested or absorbed in the human intestinal tract, or are extremely difficult to digest or absorb”. It has been shown that low-molecular-weight non-digestible oligosaccharides are fermented by intestinal microbes in the large intestinal tract and are involved in maintaining and improving health. In order to clarify the bioavailability and physiological modulation functions of non-digestible oligosaccharides, the authors have conducted hydrolysis experiments using rat and human small-intestinal enzymes, animal experiments, and human studies to evaluate their available energy value and maximum permissive dose that would not cause transitory osmotic diarrhea. In addition, using senescence-accelerated mice, we have shown that consecutive feeding with non-digestible oligosaccharides may prolong life span, prevent senile osteoporosis, and enhance the production of intestinal bacteria-derived water-soluble vitamins, including folate, vitamin B6 and B12, to prevent vitamin deficiency in the host. Furthermore, we have developed an improved method for accurate quantification of non-digestible oligosaccharides using porcine small-intestinal enzymes. Appropriate quantification of non-digestible oligosaccharides in foods is essential for estimation of their health benefits. Moreover, an accurate method for determination of newly developed non-digestible oligosaccharides is imperative for nutrition labeling of prebiotic contents to help consumers chose healthy foods.
