Antimicrobial factors in human milk.

Levels of immunoglobulins, lactoferrin and lysozyme were determined in milk samples obtained from well-nourished and under-nourished Indian women at different stages of lactation. The concentration of immunoglobulins and lactoferrin was higher in colostrum than in mature milk while the lysozyme levels showed a progressive increase with the period of lactation. There were no significant differences in the levels between the two groups of women. Administration of iron did not alter either the total or percentage saturation of lactoferrin in milk. These results indicate that antibacterial factors in milk are not influenced by the nutritional status of the mother and that iron supplementation does not interfere with the bacteriostatic function of lactoferrin.