Abstract：β-Casomorphins are opioid like bioactive peptides released on digestion of β-casein of milk. In the present study in vivo impact of consumption of β-casomorphins (BCM-7/5) was evaluated on immune response of murine gut.

The peptides were given to mice through oral intubation at a dose of 7.5 × 10−8 mol/day/animal for 15 days. Oral administration of both peptides individually increased (p < 0.01) phenotypic expression of inflammation associated molecules (MPO, MCP-1, IL-4 and histamine), humoral immune response (IgE, IgG, IgG1/IgG2a), infiltration of leucocytes in intestinal villi and mRNA expression of toll like receptors (TLR-2 and TLR-4) in mice gut. However, no changes in sIgA, IgA+ and goblet cell numbers were recorded.

These results clearly indicate that consumption of β-casein derived peptides BCM-7/5 induce inflammatory immune response in gut, most likely through Th2 pathway.