Longitudinal profiling of host- and microbe-derived lipid metabolites in human breast milk

Breast milk contains lipid metabolites and is indispensable for the growth and development of neonates and infants. However, studies investigating interindividual variations in human breast milk composition and the longitudinal changes in its constituent lipid metabolites remain limited. The temporal and individual patterns of variations in these metabolites were characterized to provide a foundation for future research on precision nutrition in infants.

Samples of human breast milk were collected shortly after birth and at 1 and 6 months postpartum, from participants who delivered healthy, full-term infants. Lipidomic analysis involving liquid chromatography coupled with tandem-mass spectrometry was used to quantify the levels of host- and microbe-derived fatty acid metabolites in the samples. The population was classified into five groups and analyzed based on the distribution of fatty acid substrate at 0 months.

Breast milk samples from 116 participants were analyzed. The group-specific metabolite profiles were classified into three distinct patterns. The concentrations of substrates and many metabolites increased from birth to 1 month, particularly among samples with lower baseline concentrations, whereas from 1 to 6 months, some metabolites remained stable, while others decreased. These patterns were associated with differences in the metabolic pathways.

Longitudinal lipid metabolites, including microbe-derived metabolites, in human breast milk and presented characteristic patterns. These findings provide foundational data for future research on precision nutrition for infants based on the metabolic profiles of breast milk.