Human milk stimulates B cell function.

The effect of human milk on B cell function was studied by using murine spleen cells stimulated with suboptimal doses of lipopolysaccharide. Cell free, defatted, filtered colostrum as well as mature breast milk showed an enhancing effect on B cell proliferation and generation of antibody secretion, but this was not seen with formula milk. The activity was heat sensitive and resisted overnight dialysis. It is suggested that this could represent an important immunological mechanism explaining the anti-infectious properties of breast milk.