Supplementation of chondroitin sulfate-oligosaccharides in skim bovine milk improves Fe uptake in a human intestinal Caco-2 cell line

Abstract

The poor iron bioavailability of bovine milk remains a nutritional problem. This study evaluated the effect of bovine chondroitin sulfate-oligosaccharides (CS-oligos) with various skim bovine milk (SBM) fractions on Fe uptake by an in vitro digestion/Caco-2 cell model. SBM was separated into casein, whey, lactose and oligosaccharides by ultrafiltration. Modified fractions representing the absence of either casein, whey, or lactose were then prepared. Extrinsic ferrous sulfate was added at 20 µmol/L. Ferritin formation in the cells was used to assess Fe uptake. It is the first study to show the effect of milk oligosaccharides on Fe uptake, which was similar to that of whey. The ferritin synthesis rate was 1.5-fold greater in SBM after the addition of CS-oligos. The enhancing effect of CS-oligos was the most prominent with milk oligosaccharides and the least with casein. The results suggest the possibility of supplementing CS-oligos into different low iron bioavailability dairy products.

Keywords

• Fe uptake
• Chondroitin sulfate oligosaccharides
• Bovine milk glycans
• Ferritin formation
• Caco-2 cells