Enhanced Protection Against Diarrhea Among Breastfed Infants of Nonsecretor Mothers

Diarrhea is a major cause of infant mortality. Being a "nonsecretor" (having an inactive fucosyltransferase-2 gene) protects against diarrhea by inhibiting enteric infections. Breastfeeding also protects against diarrhea; however, the impact of maternal secretor status is unknown. In the ALSPAC cohort (N = 4971), we found that breastfeeding by nonsecretor mothers was especially protective against diarrhea, which could inform new prevention strategies.