Rectal Transplantation of Fragmented Intestinal Organoids and Crypts Promotes Mucosal Regeneration in DSS-Induced Colitis

BackgroundUlcerative colitis (UC) represents a global health challenge characterized by relapsing inflammation and epithelial barrier disruption. Conventional immunosuppressive therapies have reached their therapeutic ceiling, with mucosal healing and long-term remission remaining unmet therapeutic goals for many patients. Organoid-based regenerative therapy offers a new paradigm by reconstructing damaged mucosa rather than merely controlling inflammation. MethodsWe hypothesized that fragmented intestinal organoids, building upon the foundational model established by Yui et al., whose use of immunodeficient Rag2-/- mice and surgical mucosal injury first demonstrated the feasibility of colon organoid transplantation. Our study advances this framework by introducing optimized transplantation timing and employing immunocompetent C57BL/6 mice to refine translational relevance and clinical feasibility, thereby extending the applicability of organoid therapy to more realistic physiological contexts., when transplanted rectally at an optimized time point, could integrate more efficiently into inflamed mucosa and accelerate epithelial regeneration even in an immunocompetent environment. A 2.5% dextran sulfate sodium (DSS)-induced colitis model was established in C57BL/6 mice. Intestinal organoids and crypts derived from EGFP-transgenic donors were cultured and transplanted rectally using a minimally invasive delivery system. Fluorescence microscopy, histological analysis, and clinical indices were used to evaluate engraftment and mucosal repair. ResultsEGFP+ organoid fragments and crypts successfully engrafted at ulcerated sites, reconstituting epithelial structures and restoring mucosal integrity. Mice receiving organoid or crypts transplantation exhibited rapid weight recovery and reduced bleeding compared to DSS-only controls. Histological and fluorescence analyses confirmed epithelial restitution exceeding 60% by day 7 post-administration versus 18% in controls. These results validate the regenerative potential of organoid transplantation within an immunocompetent host. ConclusionThis study demonstrates that rectal transplantation of fragmented intestinal organoids and crypts promotes robust mucosal regeneration in DSS-induced colitis. By optimizing transplantation timing and employing a clinically relevant model, our work establishes a translational foundation for organoid-based regenerative therapies targeting inflammatory bowel diseases.