SUMMARY CORE A: Administrative, Biostatistics, Clinical and Bionutrition Core The Administrative, Biostatistics, Clinical and Bionutrition Core of this revised application will provide scientific leadership, effective communication and budgetary and logistical support to ensure the coordinated success of all Program Project activities. It will importantly also provide specialized biostatistical and bionutritional expertise as well as perform the service of collecting patient biospecimens and clinical data to support each of the three individual Projects. This proposal seeks to build upon our established collaborative efforts and complementary expertise of the Project and Core PIs, focusing on improving our understanding of how mucin-degrading intestinal bacteria can aggravate HCT toxicities and developing novel therapeutics to target mucin-degrading activity. Our goal in this funding period will be to lay the foundation and enable clinical interventional studies that will evaluate novel strategies to reduce intestinal GVHD. Key activities of this core include: administrative support for all of the investigators in each project and core; fiscal management and oversight for each of the Projects and Cores; organization, planning, and communication of Program Project meetings and activities, including internal and external advisory board meetings. The overall goal of this Core is effective and efficient leadership of the P01. The roles of the Director, Co-investigators and administrative staff are to enable communication and provide an organizational structure while facilitating scientific, technological and logistical interactions. In order to achieve this goal, the core has established four objectives: (1) to coordinate interactions among key personnel in Projects and Cores, internal and external advisory boards, and NHLBI personnel regarding effective implementation of proposed objectives; (2) to provide biostatistical support for patient biospecimen analyses, as well as in vitro and in vivo experiments and implement plans to enable data sharing; (3) to oversee the clinical biospecimen and data collection from HCT patients at MD Anderson and Duke; and (4) to provide bionutritional expertise for real time data collection from patients, data analysis, and experimental approaches.