IMMUNOLOGICAL EFFECTS OF DIETARY PEPTIDE DERIVED FROM SOYBEAN PROTEIN

The effect of dietary peptides derived from soybean and casein on the immune responsiveness of Fisher rats has been investigated. The protein efficiency ratio of these diets was similar. The phagocytosis of opsonized sheep red blood cells by alveolar macrophages (AMphi) and the mitogenic activity of rats fed both peptides, particularly soybean peptide, were found to be significantly greater than those of rats fed the corresponding proteins of soybean and casein. Furthermore, in the pair-feeding experiment using both peptides, a comparable enhancement of the phagocytic activity of AMphi was seen in the rats given the peptides, but little difference in the natural killer cell activity was noted among rats fed each diet. It was suggested that immune activating factors would be presented in the soybean peptide.