Longitudinal changes of human milk oligosaccharides, breastmilk microbiome and infant gut microbiome are associated with maternal characteristics

Human milk oligosaccharides (HMOs) play an important role in infant health. This study aimed to investigate the association of maternal characteristics with HMOs, human breastmilk (HBM) microbiome and infant gut microbiome over the first three months of lactation. Chinese mothers and infant pairs (n = 110) were included in this prospective cohort. Secretor status linked with alpha 1,2-fucosyltransferase expression was determined by the presence of total alpha 1,2-fucosylated HMOs in HBM for 75.8% of the mothers. The concentration of dominant HMOs significantly decreased over three months except for 3'-fucosyllactose. In addition to the elevated levels of alpha 1,2-fucosylated HMOs, other neutral HMOs significantly reduced in secretors milk. Alpha-diversity of HBM and infant gut microbiome significantly increased over time, and an elevated abundance of Bifidobacterium and decreased levels of Streptococcus, Staphylococcus and Clostridium in the infant gut microbiota were noted. Multi-association analysis indicated maternal age and body mass index significantly correlated with specific HMOs and infant growth. Our study provides pivotal data on Chinese HMOs distribution profile, and their association with maternal characteristics and the infant gut microbiome.