PROJECT SUMMARY: Gastrointestinal Experimental Model Systems Core (Biomedical Research Core) The Gastrointestinal Experimental Model Systems (GEMS) Core meets the experimental and scientific needs of the members of the Texas Medical Center (TMC) Digestive Disease Center (DDC), and supports the DDC’s overall theme and mission. The GEMS Core is subdivided into two subcore: 1) organoid, and 2) gnotobiotic sub-cores. The Core’s centralized services support exciting scientific developments, are based on the unique expertise of the Core leadership, and facilitate the use of cutting-edge model systems by DDC members. The Core maintains and supplies DDC members with experiment-ready organoid cultures and gnotobiotic rodents. The Core’s organizational structure reduces cost burden for members, increases efficiency, saves time, and provides quality control for each project. The overall goal of the GEMS Core is to provide DDC members with state-of-the-art experimental model systems that are difficult to initiate and maintain in independent labs. There is no similar facility in the TMC or the region. The Specific Aims of the GEMS Core are to: 1) generate, maintain, and provide experiment-ready gastrointestinal tract organoid cultures and specialized growth reagents for membership use; 2) increase the complexity of organoid models to study infection and injury; 3) produce, house, manipulate, and colonize gnotobiotic animals per the needs of DDC members; and, 4) establish housing and embryo transfer conditions to improve the overall efficiency of the gnotobiotic model. The GEMS Core has extensive interactions with the Study Design and Clinical Research Core, the Tissue Analysis and Molecular Imaging Core, and the Functional Genomics and Microbiome Core. The GEMS Core will continue to respond to the needs of DDC members and develop new services to meet them. The Core has been heavily used by the 103 DDC members this cycle: organoid subcore by at least 31, gnotobiotics by 29 with nearly 3000 service requests resulting in over 80 publications.