(P37-22-26) Associations Among Human Milk B-vitamins and the Milk Metabolome in the MILQ Study

Objectives: B-vitamins (BVs) in human milk (HM) are crucial for infant development and cofactors of metabolic pathways. To explore these links, we studied associations of BVs with the HM metabolome.

Methods: HM (1-3.4; 3.5-5.9; 6-8.5 mo pp, n=786) from the MILQ study in Brazil, Bangladesh, Denmark, and The Gambia, was analyzed for BVs and targeted metabolomics (Biocrates MxP® QUANT 500 kit) using validated LC-MS and bioanalyzer methods. Associations were tested with linear regressions controlling for site, lactation stage, maternal age, and infant sex with cluster-correlated robust standard errors to account for repeated measures within individuals. Benjamini-Hochberg was used to control false discovery rate; association strength was quantified via Spearman correlation to aid interpretation. Significant correlations (p < 0.05) with r > 0.4 were included, and links between BVs and the 5 strongest correlating metabolites were examined.

Results: The strongest metabolite correlations were observed with flavin adenine dinucleotide (FAD), nicotinamide adenine dinucleotide (NAD), thiamine diphosphate (TDP), nicotinamide (NAM), pyridoxal (PL), and B12 varied between 0.41–0.68 (q < 0.044) with strongest associations to lipids (ceramides, triglycerides (TGs), phospholipids, sphingomyelins). Only NAD and TDP association included non-lipids (spermine, spermidine, r: > 0.58). While no direct link exists, NAD/TDP support mitochondrial and pentose phosphate metabolic flux that sustains ATP production and SAM-dependent methyl metabolism, enabling polyamine biosynthesis. NAM was only associated with ceramides, which are consistent with coupling between NAD metabolism and sphingolipid pathways involved in cellular signaling and membrane structure. PL selected correlation to TGs may be linked via pyruvate, acetyl/propionyl-CoA producing pathways feeding into fatty acid synthesis and TG assembly in the mammary gland.

Conclusions: Our findings indicate conserved regulation between HM BV-derived cofactors and bioactive lipid and polyamine pathways. Future research incorporating maternal/infant nutritional status biomarkers will provide a deeper understanding of these links and relevance to the mother-milk-infant triad.

Funding Sources: Gates Foundation; USDA-ARS intramural funds