Effect of short-chain fructooligosaccharides on intestinal calcium absorption and calcium status in postmenopausal women: A stable-isotope study

Abstract

Background: An enhancing effect of short-chain fructooligosaccharides (scFOSs) on intestinal calcium absorption has been shown in animals and in some short-term human studies. However, the long-term effect of scFOSs on calcium absorption in humans is still unknown. Objective: We investigated the long-term effect of a moderate daily dose (10 g) of scFOSs on intestinal calcium absorption in postmenopausal women. Design: In a randomized, double-blind crossover protocol, 12 healthy, postmenopausal women received scFOSs or placebo for 5 wk. The treatments were separated by a 3-wk washout period. Subjects orally received 44Ca (stable isotope) and a fecal marker. Feces were collected after the isotope intake for 5-7 d to measure unabsorbed isotope. Calcium-status indexes, calciotropic hormones, and bone turnover were also assessed. Results: Mean (± SD) intestinal calcium absorption with scFOS treatment was not significantly different from that with placebo treatment (35.63 ± 9.40% and 36.55 ± 8.48%, respectively). However, a tendency for calcium absorption to be higher with scFOS treatment than with placebo treatment was observed in women who had been going through menopause for > 6 y. Conclusions: scFOSs do not modify intestinal calcium absorption in postmenopausal women who do not receive hormonal replacement therapy. The results from a subgroup of women who had been going through menopause for > 6 y (n = 6) suggest that scFOSs may influence calcium absorption in the late postmenopausal phase. The small number of subjects and the related P value warrant verification and further investigation with women in late menopause only.