ABSTRACT
This chapter argues that milk can modulate immune responses in infants will be reviewed: the data indicate that breast-feeding indeed has important effects on immunological development. Phagocytosis of the resulting immune complexes causes release of lysosomal enzymes, which will then further increase gut permeability, only to homologous proteins, but also to unrelated molecules. The observation that total serum immunoglobulin concentrations are similar in the two feeding groups may indicate that the immune system of the breast-fed infant is stimulated by alternative mechanisms. The proliferation of peripheral blood lymphocytes in vitro has frequently been used as a measure of immunocompetence. Lymphocytes from cord blood and from newborn infants have a higher rate of spontaneous and mitogen-induced proliferation than cells from adults, an observation attributed to increased activation in vivo. Investigation of the effect of breast- and bottle-feeding on in vivo and in vitro immune responses has shown that breast-feeding has contrasting effects on the development of immunity.
