The Effect of Prebiotics on Iron Absorption in Women With Low Iron Stores: Determination of a Dose-dependent Effect of Galacto-oligosaccharides on Iron Absorption, With and Without Addition of Ascorbic Acid

Iron is an important mineral in our body and fulfills essential functions such as for example oxygen transport from the lungs to the tissues. Iron deficiency is still the most common and widespread nutritional disorder in the world according to WHO. Common iron supplements all have their limitations in terms of availability and compatibility. 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 pH, prebiotics can enhance absorption of minerals such as calcium and magnesium and they have been proposed to potentially improve iron absorption.

In a recent iron absorption study in adult women with low iron stores in our lab (publication under review), we found that 15 g of GOS given with an iron supplement in the form of iron fumarate acutely increased iron absorption when given with water and a bread based meal. The dose of 15 g of GOS was tolerated well by the participants. As a follow up to the study mentioned above, we want to investigate: 1) if acute iron absorption is affected by lower doses of GOS; 2) whether this acute effect occurs for other commonly used iron compounds as well, such as iron sulphate and iron phosphate; and 3) if there are potential interactions on absorption with other enhancers of iron absorption, such as vitamin c.