Comparison of enterotoxin-inhibitory activity in human milk and bovine milk

Abstract

Human milk contains antibodies as well as non-immunoglobulin components which most likely are of importance for the prevention of diarrhoea in infants. We have previously described the precence in human milk of a ganglioside fraction which inhibited E.coli heat labile enterotoxin in vitro and cholera toxin in vivo, as well as a trypsin-sensitive inhibitory activity of rotavirus. In this study we have compared the enterotoxin-inhibitory activity in human milk with that of bovine milk and bovine-based formula milk. Ganglioside fractions were obtained by extraction and solvent partition of the milk fat. High performance thin layer chromatography (HPTLC) showed major differences between the ganglioside fractions from human milk and bovine milk. Toxin inhibitory activity was measured in vitro by ELISA (enzyme-linked immunosorbent assay) and in vivo by rabbit intestinal loop model. In ELISA, enterotoxin was inhibited by human milk, bovine milk and formula milk. In the rabbit intestine, only human milk inhibited the enterotoxin.