MÆSTRA – Enhanced milk calcium uptake by strategic food design

Calcium uptake from the gut takes place through passive processes that are determined by the calcium solubility. Thus, the biochemical environment in the gut is decisive as the solubility of calcium is pH dependent. This fact receives increasing attention as studies have shown that calcium absorption is increased when prebiotic fibers are included in the diet. It has therefore been proposed that a gut-bone axis exists and can be added to the gut-brain, gut-liver, gut-kidney and gut-lung axes, even though the gut-bone axis is currently only sparsely studied.

By: Grith Mortensen

Milk-derived calcium has a bioavailability and is therefore a superior calcium source. The MÆSTRA project will show that the ability of milk calcium to prevent bone demineralization can be further enhanced through food matrix effects that stimulates optimal conditions in the gut. To test this hypothesis, intervention studies with rats will be conducted where the rats receive different combinations of milk calcium, lactose and fermentable fibers as well as fermented dairy products and the impact on bone mineralization is examined. Furthermore, in order to elucidate the underlying mechanisms stimulating calcium absorption in the gut, the composition and the activity of the gut microbiota will be investigated by a combination of 16S rRNA gene amplicon sequencing and metabolomics analyses. Postmenopausal women are at risk of bone demineralization and bone loss, and the studies will therefore be conducted ovariectomy-induced osteopenic rats.