Immunomodulatory Effects of Wheat Peptides and a Novel Octapeptide ( GFNDLGKR ) in Immunosuppressed Zebrafish and Mouse Models

Immunosuppression increases susceptibility to infections, highlighting the need for safe immunomodulatory strategies. This study investigated the immunomodulatory effects of wheat peptides (WP) and identified bioactive peptide sequences using zebrafish and mouse models. In chloramphenicol (CAP)‐induced immunosuppressed zebrafish, WP (150 μg/mL) significantly restored macrophage counts (32.25% increase), neutrophil fluorescence intensity (28.87% increase), and IFN‐γ levels (42.34% increase). In cyclophosphamide (CTX)‐induced immunosuppressed mice, WP (0.5 g/kg) significantly increased spleen index, thymus index, serum IgA and IFN‐γ levels, and fecal short‐chain fatty acid concentrations. LC–MS/MS peptidomics identified peptide sequences; molecular docking targeting CHRM1 revealed that the octapeptide GFNDLGKR (GR8) exhibited the strongest binding affinity (CDOCKER energy = −161.15 kcal/mol). GR8 (10 μg/mL) validation in zebrafish significantly increased macrophage counts (60.62%), neutrophil fluorescence intensity (44.03%), and IFN‐γ levels (60.84%). These findings demonstrate that WP exerts immunomodulatory effects through restoration of immune cells, organ indices, cytokines, and short‐chain fatty acids (SCFA), and identify GR8 as a promising bioactive peptide for functional food development.