The Antimicrobial Activity of Human Colostral Antibody in the Newborn

Bacterial counts in the stools of breast-fed infants were found to differ quantitatively and qualitatively from those of bottle-fed newborns. During the first four days of life, the coliform flora of the breast-fed infants was depressed, while the lactobacilli were more abundant. The levels of IgG, IgM, and IgA immunoglobulins were highest in the mothers' colostrum immediately after delivery, and they rapidly declined during the first four days. The colostrum contained substantial amounts of antibodies to Escherichia coli. Agglutinating and bactericidal activity against strains of E. coli was also detected in saline extracts of stools of breast-fed infants. Existence of a direct correlation between the concentrations of immunoglobulins and reduction of coliform bacteria in the stools of breast-fed newborns was observed.