Human milk oligosaccharides protect against enteropathogenic E.coli (EPEC) attachment in vitro and EPEC colonization in suckling mice

Breastfeeding reduces the risk of enteric bacterial infections in newborns in part due to human milk oligosaccharides (HMO), complex glycans that are present in human milk, but not in infant formula. Enteropathogenic Escherichia coli (EPEC) are attaching/effacing pathogens that cause serious diarrheal illness with potentially high mortality in infants. We isolated HMO from pooled human milk and found that they significantly reduce EPEC attachment to cultured epithelial cells. In suckling mice, administration of HMO significantly reduced colonization with EPEC compared to untreated controls. These data suggest an essential role for HMO in the prevention of EPEC infections in human infants.