1216-P: Maternal Obesity and Human Milk Metabolomics—Unraveling the Link to Infant Obesity Risk

Background: Maternal obesity is associated with increased risk of pediatric obesity and the mechanisms that account for these observations remain poorly characterized. Pre-pregnancy BMI (ppBMI) is associated with variation in human milk composition, suggesting that human milk metabolites may affect infant growth and risk of obesity.

Objective: The purpose of this study was to leverage clinical metabolomics to understand the impact of ppBMI on human milk composition in a longitudinal birth cohort.

Methods: Clinical data (n=83) for this study included normal weight (NW, pre-pregnant BMI <25.0 kg/m2) and obese (Ob, pre-pregnant BMI >30.0 kg/m2) maternal infant dyads at 3rd trimester (34-38 weeks) and followed for 12-months postpartum. Human milk samples were collected at 2-weeks and metabolomics data was generated by untargeted high-resolution liquid chromatography mass spectrometry. T-test was performed using the R statistical software to test for differences in human milk metabolomics.

Results: We found that maternal obesity was associated with changes in 170 human milk metabolites. Specifically, we found ppBMI was associated with reduced levels of human milk carbohydrates (deoxyribose, p=0.03), lipids (undecanoic acid, p=0.03), and phytochemical (pipecolate, p=0.02) compounds. We also found that ppBMI was associated with increased levels of lipids (dodecylaldehyde, p=0.02), nucleic acids (uridine, p=0.04) and peptides (ornithine, p=0.0003).

Conclusion: Our results demonstrate that maternal ppBMI was associated with changes in human milk composition and may represent a potential milk-dependent mechanism for mother-child transmission of obesity risk.