Characterization of human milk oligosaccharides from Chinese mothers and their association with delivery mode and infant eczema

Objective This study investigated how HMO profiles in Chinese mothers’ milk are affected by lactation stage and delivery mode (C-section vs. vaginal). Study design The study was based on a cross-sectional multi-center human milk study in China. Twenty-four HMOs were quantified using UPLC/MS/MS, and statistical tools were used to identify profiles and clusters of HMOs. The relationship between HMO concentrations, delivery mode and infant eczema was explored at each lactation stage. Results The study included 635 mother-infant pairs. The concentrations of HMOs varied according to lactation stage and five distinct HMO clusters were observed based on significant associations between HMOs. Milk from mothers who delivered by C-section had significantly lower concentrations of 2’FL, LNnT, 3’SL, LNFP-III, DFLNHa, DSLNT, LNDFH-II, LNnDFH-II, and DFpLNnH compared to vaginal delivery. The odds ratio for eczema was reduced in infants whose mothers had higher concentrations of LSTb in mature milk (>90 days). Conclusion HMOs in Chinese human milk vary based on lactation stage and cluster based on their structure. C-section delivery lowers the concentrations of several HMOs in the milk compared to vaginal delivery. Higher LSTb inversely associated with parent-reported infant eczema. Further research is required to confirm these findings and to understand the underlying mechanisms.