NMR-Based Metabolomic Profiling Highlights Functional Nutritional Gaps Between Human Milk, Infant Formulas, and Animal Milks

Background/Objectives: Human milk represents the gold standard for infant nutrition, providing a complex and bioactive metabolite profile essential for early development. Despite efforts to enrich infant and toddler formulas with functional ingredients, significant biochemical differences persist. This study aimed to characterize and compare the metabolomic composition of human milk, cow’s milk (both conventional and lactose-free), goat’s milk, and a variety of commercial formulas, including both infant (0–12 months) and toddler (1–3 years) formulations, using ¹H NMR-based metabolomics. Methods: A total of 90 milk samples were analyzed, including eight formula milk brands, four human milk samples, four goat milk brands, and seven cow milk products. ¹H NMR spectra were acquired and processed to identify 54 metabolites. Multivariate and univariate statistical analyses were used to assess compositional similarities and differences among milk types. Results: Human milk displayed a unique metabolic signature, enriched in fucosylated oligosaccharides (2′-FL, 3′-FL), N-acetylated carbohydrates, and amino acids such as glutamine and glutamate. Goat milk was characterized by higher levels of creatine, carnitine, and succinate, whereas cow milk showed elevated orotate, butyrate, and mannose. Formulations exhibited a relatively homogeneous composition across brands but differed from human and animal milk, particularly in choline, formate, and added micronutrients. Toddler formulas contained more energy-related compounds (e.g., creatine, maltose) compared to infant formulas. Conclusions: While modern formulas provide nutritional adequacy, they remain metabolically distinct from human milk. NMR-based metabolomics offers a powerful tool for guiding future improvements in formula composition toward more biomimetic profiles.