This study investigates the effects of Akkermansia muciniphila on CD4⁺ T cells in a DSS-induced colitis mouse model. Spleen-derived CD4⁺ T cells were isolated from mice treated with either A. muciniphila or PBS by oral gavage, followed by DSS administration. Proteomic profiling was performed using LC–MS/MS on a Thermo Scientific Orbitrap Astral mass spectrometer coupled with a Vanquish Neo UHPLC system.