Capillary Electrophoresis Analysis of Bovine Milk Oligosaccharides Permits an Assessment of the Influence of Diet and the Discovery of Nine Abundant Sulfated Analogues.

Bovine milk oligosaccharides (BMOs), like their analogues in human milk, have important prebiotic functions. Environmental factors have previously been linked to variation in BMO structures, and thus to test the hypothesis that the bovine diet may lead to these changes in relative BMO abundances, a rapid capillary electrophoresis (CE)-based work flow was developed to profile the BMOs extracted from the milk of cows fed distinctly different diets. Over the first week of lactation, few significant differences were observed between the different diet groups, with the dominant changes being clearly linked to lactation period. CE analyses indicated the presence of ten unusually anionic BMOs, which were predicted to be phosphorylated and sulfated species. Nine unique sulfated BMOs were detected by high-resolution accurate mass spectrometry, none of which have been previously described in bovine milk. The biosynthesis of these was in direct competition with 3'-sialyllactose, the most abundant BMO in bovine milk.