The aim of this prospective, single-center trial is to provide initial clinical experience regarding the safety and efficacy of endoscopic gastric and duodenal submucosal islet transplantation in type I diabetic patients with kidney allografts. A total of 6 patients will be recruited into the trial. The investigators will follow the standardized islet manufacturing protocols and the thymoglobulin-based induction immunosuppressive regimen developed by the Clinical Islet Transplant consortium (CIT). Outcomes will include safety measures, glycemic control and insulin use, metabolic assessments of graft function, allo/auto-immune responses, and protocol biopsies to assess graft rejection/inflammation. The investigators believe that this novel approach to islet transplantation has the potential to significantly improve current islet transplantation outcomes by enhancing islet engraftment and long-term function.