Influence of short-chain fructo-oligosaccharides (sc-FOS) on absorption of Cu, Zn, and Se in healthy postmenopausal women

Objective: This study was carried out to evaluate the effect of short-chain fructooligosaccharides (sc-FOS) on the absorption of Cu, Zn, and Se among postmenopausal women who are potential candidates to subclinical trace element deficiencies. Design: A randomized double blind cross-over study. Setting: This study was carried out at the Human Nutrition Research Center, Clermont-Ferrand, France. Subjects: 11 postmenopausal women aged 53-70 y, not taking hormone replacement therapy were enrolled and completed the study. Interventions: Diets with 10 g/day sc-FOS or placebo were given for 5 weeks each in random order followed by a wash-out period of at least 3 weeks. At the end of each period, stable isotopes (3.19 mg Zn-67 as ZnCl2, 2.06 mg Cu-65 as CuCl2 and 52.3 mug Se-74 as sodium selenite) and radiopaque pellets (as fecal excretion index) were administered during lunch. Stools were collected for the next 5-7 days. Isotopes were determined by ICP-MS (Cu and Zn) or GC-MS (Se). Results: Copper absorption was significantly enhanced (p = 0.042) by sc-FOS. No effect of sc-FOS was observed on Zn, and Se absorption. Conclusion: To our knowledge, this is the first study on the influence of sc-FOS on trace element metabolism. The observed increase in copper absorption may be of interest regarding daily copper requirements in menopausal women. However, the relevance of this observation remains to be established.