Gestational diabetes mellitus affects the fucosylation and sialylation levels of N/O-glycans in human milk glycoproteins

Gestational diabetes mellitus (GDM) has negative effects on mothers and offspring, which may be related to the glycosylation level of milk proteins. Here, the human milk N/O-glycome of healthy and GDM individuals was analyzed by HILIC-MS/MS. A total of 56 putative N-glycans were detected, among which 12 N-glycans were significantly different between GDM and healthy milk. A total of 25 putative O-glycans were detected, and 11 of them varied greatly between GDM and healthy milk, especially H1N1S1 and H2N2S1. Overall, the relative content of N/O-glycans in GDM milk was significantly lower than that of healthy milk. In GDM milk, fucosylated N-glycans present higher proportion, whereas the proportion of sialylated O-glycans were lower. These findings would provide a foundation for in-depth study on the structure-activity relationship of milk N/O-glycans and are expected to drive the design of infant formula for newborns.