How Does a Synbiotic Supplement Affect Iron Status During Iron Repletion in Iron Depleted Female Athletes?

Iron deficiency (ID) affects ~30% of female athletes, and its consequences are highly relevant to athletic performance. Poor iron (Fe) uptake remains a major factor in the development of ID. While animal studies suggest that prebiotics may improve Fe uptake, this has not been well-studied in humans. The main objective of the proposed study is to determine the effects of synbiotic supplementation on the Fe status of ID female athletes during Fe repletion. At the beginning of a training season at a Division III University, the Fe status of 28 female athletes (cross-country, lacrosse, basketball, field hockey) was screened. Twenty eligible athletes (baseline Hgb:12.3±0.9g/dL; sFer:18.1±9.2µg/L) were then randomized to receive either a daily synbiotic supplement (5g prebiotic fiber + 8 billion CFU probiotic B. lactis) or placebo, along with a daily Fe supplement (140 mg FeSO4/d) for 8 weeks using a double-blind design. Fe status and body composition were assessed at baseline, mid-point and after the trial. Participants were instructed to keep daily logs of supplement intake, physical activity, GI and other symptoms.