Abstract
Human milk is the primary source of infant nutrition, although breastfeeding rates are declining today, and human milk is often replaced by animal milk-based infant formula. Infant formula is intended to replicate the composition of human milk, albeit significant differences remain in the physiological responses to breastfeeding and formula feeding in offspring. More research is needed on the composition of human milk and other milk types, especially regarding their lipid content. A comparative analysis of different milk samples was carried out in this study. The amount of omega-3 fatty acids, omega-6 fatty acids, and endocannabinoids was measured in human, cattle, and goat milk as well as in goat milk- and cow milk-based infant formulas using chromatography coupled to mass spectrometry. Significant differences between the human and animal milks were observed in the case of omega-6 fatty acid and endocannabinoid content, with higher omega-6 fatty acid and lower endocannabinoid levels in human milk than in animal milk samples and infant formulas. Goat milk shares the highest similarity to human milk in terms of the analyzed lipid species. However, our results indicate that the levels of the examined bioactive lipid species in human milk failed to be replaced by goat milk- and cow milk-derived infant formulas.