Novel Noninvasive Broad‐Spectrum Infrared Treatment of Ulcerative Colitis by Modulating T‐Cell Relocation

Ulcerative colitis (UC) is an incurable inflammatory bowel disease characterized by chronic mucosal inflammation, with a continuously increasing global prevalence. Although infrared (IR) therapy has demonstrated anti‐inflammatory potential, conventional devices that can only emit single‐wavelength IR often exhibit limited tissue penetration and poor suboptimal spectral overlap with mammalian absorption. Herein, we develop a broad‐spectrum infrared (BSIR) device enabled with an almost defect‐free graphene based radiator to deliver high output IR aligned with mammalian IR absorption spectra. In a mouse model of UC, BSIR treatment significantly alleviated disease symptoms and promoted mucosal recovery. Crucially, this study shows that BSIR radiation induces the relocation of T lymphocytes to the spleen, leading to reduced immune cell infiltration and inflammation in the colon. Gene expression analysis further reveals enhanced innate immune activity and cell regeneration in colonic tissue. Collectively, these findings demonstrate that BSIR represents a safe, noninvasive therapeutic strategy for UC. More broadly, this study highlights spectrum‐matched IR irradiation as a novel modality for immune modulation, with potential translational relevance for other deep‐tissue inflammatory diseases.