Lipidomics of Brain Tissues in Rats Fed Human Milk from Chinese Mothers or Commercial Infant Formula

Holistic benefits of human milkto infants, particularly brain development and cognitive behavior, have stipulated that infant formulabe tailored in composition like human milk. However, the composition of human milk, especially lipids, and their effects on brain development is complex and not fully elucidated. We evaluated brain lipidomeprofiles in weanlingrats fed human milkor infant formulausing non-targeted UHPLC-MS techniques. We also compared the lipid composition of human milkand infant formulausing conventional GC-FID and HPLC-ELSD techniques. The sphingomyelinclass of lipids was significantly higher in brains of rats fed human milk. Lipid species mainly comprising saturated or mono-unsaturated C18 fatty acids contributed significantly higher percentages to their respective classes in human milkcompared to infant formulafed samples. In contrast, PUFAs contributed significantly higher percentages in brains of formula fed samples. Differences between human milkand formula lipids included minor fatty acids such as C8:0 and C12:0, which were higher in formula, and C16:1 and C18:1 n11, which were higher in human milk. Formulaalso contained higher levels of low- to medium-carbon triacylglycerols, whereas human milkhad higher levels of high-carbon triacylglycerols. All phospholipid classes, and ceramides, were higher in formula. We show that brain lipid composition differs in weanlingrats fed human milkor infant formula, but dietary lipid compositions do not necessarily manifest in the brain lipidome.