Dynamic Variations in Endogenous Peptides in Chinese Human Milk Across Lactation and Geographical Regions

Area of Science:

• Human milk proteomics
• Endogenous peptide analysis
• Infant nutrition

Background:

• Human milk composition is crucial for infant development.
• Understanding endogenous peptides in milk is vital for infant health.
• Limited data exists on human milk peptide profiles across diverse Chinese populations.

Purpose of the Study:

• To characterize the endogenous peptide profile of human milk.
• To investigate variations based on lactation stage and geographic region.
• To explore correlations between peptides, maternal diet, and infant growth.

Main Methods:

• Orbitrap Fusion Lumos LC-MS/MS analysis of human milk samples.
• Multicenter cohort study (n=200 mothers) across seven Chinese regions.
• Samples collected at 2 and 6 months postpartum.

Main Results:

• Identified 6960 peptides from 621 proteins.
• Polymeric immunoglobulin receptor (PIGR) peptides higher at 2 months, indicating immune function.
• Regional variations observed, with Lanzhou milk showing higher beta-casein (CASB) and butyrophilin (BTN1A1) peptides.

Conclusions:

• Maternal dietary fat intake positively correlates with specific antimicrobial peptides (CASB variants).
• Infant growth inversely correlates with some antimicrobial peptides, but CASB_200-225 shows a positive association.
• Findings provide insights into human milk peptide dynamics for breastfeeding and formula design.