 According to the WHO, iron deficiency is still the most common and widespread nutritional disorder in the world. Current iron supplements have limitations in terms of bioavailability and tolerability. Prebiotic fibers, such as galacto-oligosaccharides GOS, selectively enhance growth of beneficial colonic bacteria. Prebiotics in general enhance the production of short-chain fatty acids SCFAs and thereby decrease luminal pH. Through the reduction in colonic pH, prebiotics can enhance absorption of minerals such as calcium and magnesium and they have been proposed to potentially improve iron absorption as well. 