The effect of human colostrum on neutrophil function.

Strains of Escherichia coli were opsonized in human colostrum via heat stable opsonins and the classic complement pathway, but colostrum lacked capacity to opsonize E. coli via the alternative pathway. There was no bacteriostatic activity against serum sensitive E. coli strains, although specific antibodies against the strains were present. Neutrophils suspended in colostrum had normal chemotaxis and this was not altered by treating the colostrum with HCl.