Protection of breast-fed infants against Campylobacter diarrhea by antibodies in human milk.

To investigate the role of breast-feeding in preventing diarrhea caused by Campylobacter jejuni, we followed 98 Mexican children prospectively for 2 years beginning at their birth. Attack rates of diarrhea in children less than 6 months of age who were not fed human milk were 2.3 times greater than those in children of the same age who were fed human milk. Breast-fed children remained free of diarrhea for a longer time than non-breast-fed children (p less than 0.0005). The diarrhea attack rate caused by C. jejuni for non-breast-fed infants was significantly greater (p less than 0.005) than that in the breast-fed group. Secretory IgA milk antibody titers against glycine acid-extractable antigen of C. jejuni were high in colostrum, decreased during the first month of breast-feeding, and generally persisted throughout lactation. Human milk consumed by children in whom Campylobacter diarrhea developed did not contain secretory IgA antibodies to the glycine acid-extractable common antigen of Campylobacter. This study shows an association between Campylobacter antibodies in human milk and prevention of diarrhea caused by Campylobacter.