PIP: This editorial reviews current knowledge of the mechanisms by which breastfeeding protects infants against gastroenteritis and other infections. Breast milk averts the disadvantage of contamination with micro-organisms in the handling process common to indigenous foods used in the weaning period and commercial milk products. The infections caused by contaminated food and water compound the malnutrition already caused by inadequate weaning food. Human milk is thought to contain several nonspecific and specific factors that provide protection against infections such as gastroenteristis and upper respiratory tract infections. Analogues to epithelial cell receptors may prevent the mucosal attachment of potential pathogens. Protection of the breast-fed infant against cholera has been shown to be related to the level of the IgA antibodies in the mother's milk against the cholera lipoplysaccharide and enterotoxin.