Two-week feeding of difructose anhydride III enhances calcium absorptive activity with epithelial cell proliferation in isolated rat cecal mucosa

Objective Ingestion of difructose anhydride III (DFAIII) enhances calcium (Ca) absorption in rats. The present study investigated the mechanism involved in increased Ca transport by DFAIII ingestion. The short-term and long-term effects of DFAIII feeding on Ca transport were determined by using isolated epithelium from the small and large intestine in rats. Methods Male Sprague-Dawley rats were fed an 8% cellulose or 5% cellulose plus 3% DFAIII diet for 14 d. Net epithelial Ca transport in the small intestine, cecum, and colon was compared between the two diet groups by using an Ussing chamber. The contents and epithelial tissues in the cecum were analyzed. Results There were no differences in basal and luminal DFAIII-induced Ca transport in the isolated small intestinal and colonic mucosa between the two diet groups. Basal and lumen DFAIII-induced Ca transport in the cecum in the DFAIII-fed group was higher than that in the control group. A decrease in pH and an increase in Ca pools, short-chain fatty acids, or organic acids in the cecal contents and in the depth and number of cells in crypts in cecal tissue were observed. Conclusions The increase in Ca transport involved two mechanisms: the presence of DFAIII in the small intestine directly affected the epithelial tissue and caused increased Ca absorption as a short-term effect, and the degradation of DFAIII by microbial fermentation produced short-chain fatty acids and subsequently enhanced Ca absorption in the large intestine as a long-term effect.