OR03-04 Lipidomic Insights Into Breast Milk: Impact on Infant Body Composition and Growth

Abstract Disclosure: A. Uniyal: None. C. Lu: None. D. Jonathan: None. E.M. Nagel: None. A. Peña: None. M.C. Rudolph: None. D.A. Fields: None. E. Demerath: None. E. Isganaitis: None. Introduction and Objectives Breast milk is a dynamic fluid rich in both nutritive and nonnutritive compounds that support infant development and growth. The lipidome of human milk may reflect both maternal diet and metabolic health, which may impact infant metabolic, endocrine, and inflammatory phenotypes. Higher breast milk levels of 12,13-diHOME, a signaling lipokine, have been linked to lower 1-month infant fat mass and reduced BMI Z-score gain. We aimed to study the relationship between the human milk lipidome and adiposity measures during infancy. Hypothesis: The milk lipidome is associated with changes in infant growth and body composition in the first 6-months postpartum. Methods: We analyzed breast milk from 117 mother-infant pairs at 1-month using high-sensitivity LC/GC-MS lipidomics (BPGbio, Inc.), and assessed infant growth (weight for age-z-scores: waz, length-age-z score: laz) and body composition (fat mass, fat free mass, % body fat) from birth to 6 months (0, 1, 3, 6 months) using air-displacement plethysmography (ADP) and Dual Energy Xray Absorptiometry (DXA). We calculated Pearson correlation coefficients (unadjusted) between individual signaling and structural lipids (exposure) with infant growth measures and body composition measures (outcome). We used FDR<0.05 to denote statistical significance after adjustment for multiple comparisons. Results: We included 117 mother infant dyads with maternal age of 32.2 ±3.5 (mean ±SD) years and gestational age of 39 ±1 weeks, with 71 male and 46 female infants. Lipidomic analysis identified 51 signaling lipids and 516 structural lipids. Abundance in several structural lipids at 1-month postpartum was associated with infant growth measures at 3-months and with infant fat mass at 6-months. For infant growth measures at 3- months with FDR<0.05, 9 lipids were associated with infant weight for age z scores, and 23 lipids were associated with infant length for age z scores; highest ranking lipids included Triglycerides (TG) (14:0_16:0_20:4) (waz : r = -0.35, FDR 0.04, laz r =-0.39, FDR=0.02) and TG (16:0_18:0_20:4) (r =-0.38, waz FDR =0.03, laz: r =-0.40, FDR=0.02). Abundance of 91 lipids in milk at 1-month predicted reduced infant fat mass at 6 months with the highest-ranking lipids being TG (10:0_18:1_18:2) (r = -0.39, FDR= 0.038) and TG (10:0_16:0_18:2) (r = -0.37, FDR=0.038). Conclusion: Plasmenyl-PE, diacylglycerol (DG), and triglyceride (TG) derivatives were among the top lipid classes linked to weight and adiposity measures, with the majority of associations showing an inverse relationship between lipid abundance and infant adiposity. Additional research is needed to clarify the mechanistic relationship between breast milk lipids and infant health. Presentation: Saturday, July 12, 2025