Galactooligosaccharide (GOS) Supplementation and Calcium Absorption in Girls

The Effect of Galactooligosaccharide (GOS) Supplementation on Calcium Absorption and Retention in Female Adolescent Girls

The purpose of this study is to determine the effects of galactooligosaccharide (GOS) supplementation on calcium absorption and and gut microbe profiles.

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.

Inclusion Criteria:

• Female between ages of 10 and 12
• Calcium intake of 900-1300 mg/d

Exclusion Criteria:

• Take medication that influences calcium metabolism
• Any disorder of calcium or bone homeostasis
• BMI>90th percentile for age
• Smoking, illegal drug consumption
• Any gastrointestinal disease (crohn's disease, celiac disease, inflammatory bowel disease)
• Any disease affecting kidney function
• Broken bone within last 6 months
• Dislike of yogurt or yogurt drinks
• Regular use of foods containing probiotics or prebiotics