Comparison of the antipathogenic effect toward Staphylococcus aureus of N ‐linked and free oligosaccharides derived from human, bovine, and goat milk

N ‐linked oligosaccharides ( N ‐glycans) derived from milk were recently found to be antipathogenic. This study compares the antimicrobial activity of N ‐linked glycans and free oligosaccharides from human, bovine, and goat milk against Staphylococcus aureus . Milk N ‐glycans showed a bactericidal/bacteriostatic effect on the pathogen when compared to free milk oligosaccharides, evidenced by the clear zone from the halo assay, with the order of human milk >goat milk >bovine milk. None of the free milk oligosaccharide samples were bactericidal/bacteriostatic, despite its positive results in growth curve and minimum inhibitory concentration (MIC) assays which are believed to be related to hyperosmosis. Both N ‐glycans and free milk oligosaccharides can reduce the adhesion of Staphylococcus aureus to Caco‐2 cells, however, N ‐glycans worked significantly more effective than free milk oligosaccharides. Structural analysis of all free oligosaccharide and N ‐glycan samples showed the obvious interspecies differences, and the structure/function relationship of the respected N ‐glycans is of interest for future study. The significant bactericidal/bacteriostatic activity possessed by human, bovine, and goat milk N ‐linked glycans holds great potential as a novel substitute for antibiotics.