Modulation of the Colonic Luminal Environment by Food Factors

(JSNFS Award for Young Investigator (2020))

Abstract

This study investigated the effects of food factors on colonic microbiota, fermentation products, mucins, immunoglobulin A (IgA) and alkaline phosphatase (ALP) activity. Based on a study of glucomannan-containing lily bulbs, we demonstrated that the consumption of soluble dietary fibers, including glucomannan and non-digestible oligosaccharides, frequently increased colonic ALP activity by upregulating the expression of IAP-I in rats. We then investigated whether nutritional conditions influence these effects of non-digestible carbohydrates on colonic ALP activity. It was found that the types of dietary fat influenced the effects of dietary oligosaccharides on the colonic luminal environment, including ALP activity. Colonic ALP activity was positively correlated with colonic luminal variables such as the fecal mucin level, the ratio of Bifidobacterium spp., and the level of n-butyrate, which are associated with a more favorable colonic environment. We propose that the increase of colonic ALP activity induced by fermentable non-digestible carbohydrates may be important for protection of gut epithelial homeostasis.