This is the renewal application for Years 31-35 of a training program designed to produce investigators at the cutting edge of research in pediatric gastroenterology. Trainees will be at the postdoctoral level and a mixture of MDs and PhDs supported for up to 3 years for a total request of 5 stipends/yr. to accomplish these goals. For all trainees, the program has traditionally placed strong emphasis on molecular biology, the rationale being that molecular approaches are of central importance in both study and treatment of diseases associated with pediatric gastroenterology. In the current proposal there also is emphasis on bringing the results of molecular research to the bedside with opportunities for intense training in clinical research. The mentors (6 MDs, 5 MD/PhDs and 9 PhDs) represent a multidisciplinary group of experienced investigators from various departments at Baylor College of Medicine (BCM), the University of Texas Health Science Center, and the Methodist Hospital Research Center. Their research covers four broad areas important to pediatric gastroenterology, namely: mucosal biology, molecular hepatology, immunology and microbiome, and clinical translational. All mentor laboratories are well funded and well equipped. Faculty members have excellent track records of mentoring and interaction and participation in our training program activities. The Program Director, Robert J. Shulman, MD maintains ultimate authority for the program and manages day-to-day operations. He is assisted by an Associate Program Director (Douglas G. Burrin, PhD for additional expertise in basic science research). Major administrative decisions (e.g., selection of trainees) are handled by an Executive Committee, which includes the Program Director, Associate Director, four other program faculty, and a senior faculty member not associated with this grant. The training program for MD fellows includes research rotations to facilitate selection of a mentor. Both MD and PhD trainees have individual research committees, must prepare a written research proposal to be defended to the research committee, and have semiannual reviews that include research progress and academic and career assessment. Both MD and PhD fellows are required to attend a weekly gastroenterology/hepatology/nutrition pathophysiology course, a bimonthly research seminar series, a monthly journal club, and a thrice yearly scientific social. All trainees (MD and PhD) must present at these meetings. Trainees are selected from a highly competitive applicant pool that already exists at BCM. Over the past 15 years, trainees have performed well, with over 82% of MDs and PhDs remaining in academia and others in research positions (e.g., pharmaceutical); the majority has been successful in securing funding for their research including R01, K08, K01, K23, R03, R21, F32 grants, as well as from other competitive sources. The current proposal includes several new features designed to enrich and enhance the e...