Regional and longitudinal dynamics of human milk protein components assessed by proteome analysis on a fast and robust micro-flow LC-MS/MS system.

An in-depth exploration of molecular composition of human milk could provide a scientific basis for the development of substitutes. The present study was conducted to analyze human milk proteins from 110 individuals from five regions of China and across three stages of lactation to investigate the change patterns. We developed a micro-flow liquid chromatography tandem mass spectrometry (μLC-MS/MS) system with data-independent acquisition (DIA) proteomics technology that can rapidly and stably characterize the human milk proteome. In total, 2796 proteins were identified. Among these proteins, CPM, ACSL1, and RPL13 changed significantly during lactation, and SCP2, GALK1 and GALE changed significantly between regions. Bioinformatics analysis revealed that human milk is altered by complex interactions between genetic and environmental factors. Our results not only reveal the regional and longitudinal patterns of change in human milk proteome but also provide theoretical basis and technical support for the production and quality control of infant formula.