# Impact of Maternal Metabolic Status on Human Milk Oligosaccharide Composition: A Population-Based Cross-Sectional Study in Central South China

## TL;DR

This study explores how a mother's metabolic health affects the composition of human milk oligosaccharides, which are important for infant development.

## Contribution

The study identifies specific maternal metabolic factors, like BMI and heart rate, that influence the levels of certain human milk oligosaccharides.

## Key findings

- 3′-sialyllactose levels were negatively associated with pre-pregnancy BMI in secretor mothers.
- Triglycerides and LDL cholesterol mediate the relationship between maternal BMI and 3′-SL levels.
- HMO composition varied by maternal age and lactation period.

## Abstract

Background: Human milk oligosaccharides (HMOs) serve as critical bioactive components supporting infant growth and development. However, the influence of maternal metabolic factors during lactation on HMOs remains to be fully elucidated. This study aimed to investigate the association between maternal metabolic factors and HMOs, as well as the potential mediating effects of these factors. Methods: An observational cross-sectional study was conducted in Central South China, enrolling 196 lactating mothers. HMOs were quantified using liquid chromatography-tandem mass spectrometry. Maternal metabolic factors were assessed through physical examinations. Associations between metabolic factors and HMOs were analyzed using linear regression, and mediation effects were evaluated. Results: HMOs from Central South China were predominantly composed of neutral fucosylated HMOs. Significant differences were observed in the levels of several HMOs across maternal age groups and lactation periods. The concentration of 3′-sialyllactose (3′-SL) exhibited a negative association with the pre-pregnancy body mass index (BMI) (β = −0.16, 95% CI: −0.29, −0.03; p = 0.02), while a positive association was found with maternal heart rate (β = 0.14, 95% CI: 0.01, 0.27; p = 0.04). However, these associations were different between secretor and non-secretor mothers. Associations of 3′-SL with pre-pregnancy BMI and maternal HR were only found in the secretor mothers. Triglycerides and low-density lipoprotein cholesterol mediated the associations between maternal pre-pregnancy BMI and 3′-sialyllactose (3′-SL). Conclusions: The variations of several HMOs among mothers from Central South China were associated with maternal age and lactation period. The concentration of 3′-SL was negatively correlated with maternal pre-pregnancy BMI. The potential mechanism underlying the influence of maternal BMI on 3′-SL levels may involve maternal lipid metabolism and genetic factors.