Galactooligosaccharide (GOS) Supplementation and Calcium Absorption in Girls

Galactooligosaccharides (GOS) have been shown to have positive effects on calcium absorption in animals and postmenopausal women. This study aims to see whether the addition of fiber in the form of GOS to a calcium-containing yogurt drink will increase calcium absorption compared to placebo in a group of girls near menarche. Secondary outcomes are to assess physical fitness and determine the relationship between physical fitness and calcium absorption in adolescent girls as well as assess changes in gut microbiota. During this three phase, randomized, controlled crossover study, participants will consume yogurt drinks supplemented with 0, 2.5 or 5 grams of GOS twice daily for three weeks. Following each three week period, participants will complete a weekend clinical visit to measure calcium absorption. Height, weight, bone density and geometry, calcium absorption, gut microbiota and physical fitness will be measured. Effects of this GOS fiber intervention may help elucidate a mechanism of action for improving bone health with fiber supplementation.