Promotive effects of nondigestible disaccharides on rat mineral absorption depend on kind of the saccharide. Running head Disaccharides and mineral absorption Authors

OBJECTIVE: We examined the effects of feeding nondigestible disaccharides, difructose anhydride III (DFAIII), maltitol, melibiose and cellobiose on calcium, magnesium and iron absorption in comparison to fructooligosaccharide (FOS) in normal and ovariectomized rats. METHODS: In experiment 1, six groups of male Sprague-Dawley rats were fed either a control diet (100 g cellulose/kg diet) or test diets containing 30 g of FOS or the four nondigestible disaccharides in place of the cellulose in the control diet for 4 wk. In experiment 2, two groups of female Sprague-Dawley rats (sham or ovariectomized) were divided into four subgroups and fed either the control or test diet containing FOS, DFAIII and melibiose for 5 wk. Feces and cecal contents were collected to evaluate mineral absorption and cecal fermentation. RESULTS: In experiment 1, calcium absorption in the all disaccharides groups except the cellobiose group, magnesium absorption in the all test diet groups, and iron absorption in the FOS, DFAIII and melibiose groups were higher than those in the control group, respectively. In ovariectomized rats (experiment 2), calcium absorption in the DFAIII and melibiose groups, magnesium absorption in the all test diet groups, and iron absorption in the DFAIII group alone were higher than those in the control group, respectively. Cecal organic acids were positively and pH was negatively correlated with the absorption of these minerals, although the effects varied. CONCLUSIONS: Nondigestible disaccharides increase calcium, magnesium, and iron absorption in normal and ovariectomized rats; however, the effects depend on the disaccharide tested, a fact that may partly be associated with the cecal fermentation of these disaccharides.