Several studies have been carried out to establish the role of calcium and magnesium in bone. These minerals may play an important role in bone structure or strength. Fructooligosaccharides (FOS) are known to be stimulators of intestinal mineral absorption. In intact rats, bone volume and the mineral content (Ca, and Mg ) of the bone surface are greater in FOS-fed rats. Moreover, a significant relationship exists between the absorption of these minerals and their content in bone. Osteopenia is known to follow total gastrectomy in animals, leading to the severe concordant loss of both cortical and cancellous bone. These findings are similar to senile osteoporosis in humans. Dietary FOS completely prevents the gastrectomy-induced osteopenia in rats. If similar effects are found in humans, an increase in mineral deposition in bone during growth may contribute to the prevention of bone disease with age. Thus FOS might be a promising prebiotic for bone.