关键词: 母乳；羊乳；牛乳；游离寡糖；免疫调节；机制

Abstract: Human milk free oligosaccharides (HMOs) play a critical role in the early development of the infant immune system. Goat milk free oligosaccharides (GMOs) exhibit greater structural and quantitative similarity to HMOs compared with bovine milk free oligosaccharides (BMOs). In this study, neutral and acidic free oligosaccharide fractions were efficiently prepared from human, goat, and bovine milk using DEAE-52 weak anion-exchange cellulose chromatography combined with graphitized carbon solid-phase extraction. The immunomodulatory activities of these fractions and their underlying mechanisms were comparatively investigated in RAW264.7 macrophages. The results showed that all oligosaccharide fractions exhibited immunomodulatory activity. Notably, human milk sialylated free oligosaccharides (SHMOs) and goat milk sialylated free oligosaccharides (SGMOs) demonstrated stronger activity than bovine milk sialylated free oligosaccharides (SBMOs), potentially mediated through upregulation of the mitogen-activated protein kinases signaling pathway. Finally, online liquid chromatography-mass spectrometry was employed for qualitative and quantitative comparative profiling of SHMOs, SGMOs, and SBMOs. The results revealed that SGMOs shared greater structural homology with SHMOs, which may account for their enhanced immunomodulatory potency.

Key words: human milk; goat milk; bovine milk; free oligosaccharides; immunomodulation; mechanism