Influence of the disaccharide lactitol on intestinal absorption and body retention of calcium in rats.

Various sugars are known to stimulate intestinal calcium absorption by a mechanism that is still poorly understood. One of those, the disaccharide 4-gal-actosyl-sorbitol (lactitol), is only metabolized in the large intestine, where it is converted into acidic residues. We investigated the effect of this compound on net intestinal absorption and body retention of calcium in rats. Because dietary calcium is in a poorly absorbable form when it reaches the large intestine, attempts were made to modify the absorption of calcium present in the large intestine contents by administering lactitol. Net intestinal absorption and body retention of calcium were significantly increased by 2.5 g lactitol/(kg b.w.d) given by a gavage over a 7-d period. This was associated with a lower pH and a better availability to absorptive systems of calcium present in the large intestine contents. The results indicate that in rats lactitol given chronically increases net intestinal absorption of calcium with a subsequently more positive calcium balance.