Abstract
Helicobacter pylori is probably the commonest bacterial infection of humankind. In adults, colonization of the stomach is associated with chronic gastritis and duodenal ulcer disease. However, children in the developing world acquire H. pylori soon after birth, and there is evidence that it plays a part, through suppression of the gastric acid barrier, in the pathogenesis of the syndrome of diarrhoea, malnutrition and growth failure. Infants born of mothers who secrete milk with high levels of anti-H. pylori immunoglobulin A (IgA) antibody acquire the infection later than those born of mothers with low specific antibody levels. Enhancement of maternal breast milk anti-H. pylori IgA levels may protect infants from H. pylori infection during the vulnerable weaning period when many are susceptible to enteric infections, leading to recurrent diarrhoea and adverse consequences on nutrition and growth.