Abstract
We have investigated the functional properties of food ingredients and nutrients in the intestine with special reference to anti-disease functions. This review article introduces our nutritional studies of protective factors such as resistant protein and vitamin B6 through their effects in the intestine. (1) We have obtained evidence that the hypocholesterolemic activity of buckwheat protein is at least partially due to its lower digestibility by intestinal proteases. On the basis of these studies, we proposed the novel concept of “resistant protein”. This issue has been investigated in studies using a silk protein, sericin, as a resistant protein. Furthermore, we have successfully developed a method for production of the undigestive fraction from sake cake. (2) We have demonstrated a strong anti-tumor effect of dietary vitamin B6 in the colon of mice, and studied the molecular mechanisms involved. According to several recent studies, the anti-tumor effect of vitamin B6 appears to be more profound in the colon than in other organs. Therefore, vitamin B6 is now considered to be a protective food factor against colon cancer.
