Immunomodulating effects of egg yolk low lipid peptic digests in a murine model

There is a close link between nutrition and immunity. Bioactive peptides derived from various protein sources have been demonstrated to exert immunomodulating effects. Those activated sequences may also be found in egg yolk. When administered in vivo to chicken, egg yolk digests prevented bacterial infections. Thus, egg yolk low lipid peptic digests' (EYLLPD) effects were studied in a murine model to elucidate their action's mechanism and immunomodulating capacity. The mucosal immune response was investigated by immunohistochemistry. IL-6 production was evaluated by ELISA. The results show that EYLLPD induces an immune response with an increase in IgA+ cells, while orchestrating the Th1/Th2 response. Furthermore, they reveal a potential role of the epithelium in the effects of EYLLPD at the epithelial surface, as suggested by the increase of the IL-6 secretion by small intestinal epithelial cells (SIEC). In summary, this study shows that EYLLPD enhances mucosal immune responses and that SIEC might have played an important role in preventing the bacterial infection.