Oral Antioxidant-Engineered Probiotics for the Treatment of Radiation-Induced Colitis.

Radiation colitis is an inflammatory response induced by damage to colonic tissue from radiation therapy that primarily affects patients undergoing abdominal or pelvic radiation treatments. In this study, we designed a selenium-loaded probiotic (EcN-Se@SA) encapsulated in sodium alginate gel for the oral treatment of radiation colitis. Selenium nanoparticles (Se NPs) exhibit antioxidant, anti-inflammatory, ferroptosis, and tissue repair-promoting properties. To enhance the therapeutic efficacy of Se NPs for radiation-induced colitis, we combined Se NPs with Escherichia coli Nissle 1917 and encapsulated them in sodium alginate hydrogel. The resulting EcN-Se@SA formulation not only withstands gastric acid and intestinal fluids but also remains in the colon and cecum for extended periods. Oral administration of EcN-Se@SA attenuates X-ray-induced colitis in mice through its antioxidant and anti-inflammatory effects, macrophage reprogramming, and inhibition of ferroptosis in histiocytes. This work introduces a promising therapeutic candidate for the treatment of radiation colitis.