Systematic Characterization of the Oligosaccharide Profile of Human Milk in Rural Areas of Central China: Quantitative Tracking of Human Milk Oligosaccharide Composition during 12 Months of Lactation

This study investigates changes in human milk oligosaccharide
(HMO)
composition over a 12 month breastfeeding period in rural central
China. The HMO profiles of 97 mothers were analyzed by graphitized
carbon liquid chromatography–electrospray ionization–mass
spectrometry. This method was simple to prepare samples and can simultaneously
and absolutely quantify at least 20 neutral and acidic HMOs. All mothers
were classified into four milk groups based on the presence or absence
of specific α-1,2 and α-1,4-fucosylated HMOs. The main
oligosaccharides in milk groups I and II were 2′-FL, LDFT,
LNFP-I, and LNDFH-I, while LNT, 3-FL, LNFP-II, LNFP-V, LNDFH-II, and
DFLNH-b were predominant in milk groups III and IV. Additionally,
the lactation period was the primary factor affecting the concentration
of individual HMOs. The concentrations of most HMOs decreased with
lactation and stabilized after 180 days. However, the concentrations
of 3-FL, LDFT, and LNDFH II increased gradually over the lactation
period, and the concentration of 3′-SL decreased during early
lactation (5–180 days) but increased during later lactation
(180–365 days). Furthermore, Spearman correlation analysis
revealed that maternal factors and infant factors may also affect
the concentration of various HMOs. These findings provide fundamental
insights for the development of a comprehensive human milk database.