Human milk glycosaminoglycans inhibit in vitro the adhesion of Escherichia coli and Salmonella fyris to human intestinal cells

BACKGROUND: Breast-fed infants have a lower incidence of acute gastroenteritis due to the presence of several anti-infective factors in human milk. The aim of this work is to study the capacity of human milk glycosaminoglycans (GAGs) to inhibit the adhesion of some common pathogenic bacteria. METHODS: GAGs were isolated from a pool of milk samples collected from different mothers during the first month of lactation. Experiments were carried out to study the ability of GAGs to inhibit the adhesion of two intestinal micro-organisms (enteropathogenic Escherichia coli serotype 0119 and Salmonella fyris) to Caco-2 and Int-407 cell lines. RESULTS: The study showed that the GAGs had an anti-adhesive effect on the two pathogenic strains studied with different degrees of inhibition. In particular, in the presence of human milk GAGs, the adhesion of S. fyris to Caco-2 cells and to Int-407 cells of both tested strains was significantly reduced. CONCLUSION: Our results demonstrated that GAGs in human milk can be one of the important defensive factors against acute diarrheal infections in breast-fed infants.