Fructooligosaccharides stimulate the absorption of magnesium from the hindgut in rats

We investigated the effects of feeding fructooligosaccharides (FO) on the absorption of Mg from the hindgut in cecal-cannulated rats in vivo. Male rats, four wks old male rats, were divided into four groups. Rats in two groups were fed Mg-containing diet and other two groups were fed Mg-free diet with cecal infusion of Mg. Rats of both groups were fed FO-free or FO-containing diet, respectively. The absorptive ratio of Mg administrated into the cecum was similar to that of ME fed orally in rats fed FO-free and FO-containing diet, respectively. FO-feeding significantly increased the apparent absorption of Mg in both rats fed ME orally and rats with Mg infused into the cecum. Moreover, the extent of the increase in the absorption of Mg by infusion into the cecum and by oral feeding was the same. In a separate experiment, we observed that only the rats fed Mg-free diet exhibited auricular and facial peripheral hyperemia and hemorrhage. However such symptoms were not observed in the rats with Mg infused into the cecum. In conclusion, these results indicate that FO-feeding stimulates absorption of Mg in the hindgut mainly.