AGA Future Leaders Program Mentor Biographies

J. Sumner Bell, III, MD, AGAF

Alan D. Levine, PhD
Professor of Molecular Biology and Microbiology Chief Operating Officer of the Case Western/University Hospitals Center for AIDS Research, Cleveland, OH

Alan D. Levine, Ph.D. is professor of Molecular Biology and Microbiology and holds secondary appointments in the departments of Pathology, Pharmacology, Cell Biology, Medicine / Division of Gastroenterology and Liver Disease, Pediatrics, and Oncology at Case Western Reserve University School of Medicine. Dr. Levine received his undergraduate training at Union College in Schenectady, NY and a PhD in Molecular Biophysics and Biochemistry from Yale University, before going to Stanford University Department of Cell Biology for his postdoctoral research.  He spent 11 years establishing the Molecular Immunology program at Monsanto in St. Louis, and joined the faculty of Case Western in 1995.

Dr. Levine’s research interests include investigations on immunopathogenesis of the intestinal innate and acquired immune response in inflammatory bowel disease and during an HIV-1 infection, further complicated in substance dependent individuals. His laboratory focuses on the mechanisms that regulate a complex multi-tiered host defense system of the intestinal mucosa, the largest lymphoid organ of the body. He has a broad background, training, and expertise with publications in immunology, mucosal immunology and biology, cell biology, biochemistry, cytokine biology, inflammatory diseases, and animal models, and currently directs projects on cellular mechanisms involved with the intestinal epithelial barrier in HIV-infected individuals and chronic narcotic pain medication users.

Dr. Levine serves on the University Budget Committee, which advises the Provost and Chief Financial Officer, directs the Addiction Initiative on campus, governs the Human Health Alliance for the university, is Chief Operating Officer of the Case Western Reserve University /University Hospitals Center for AIDS Research (CFAR), and serves as Graduate Program Director for the Molecular Virology, Molecular Biology, and Cell Biology doctoral programs.


C. Prakash Gyawali

C. Prakash Gyawali, MD, MRCP, AGAF
Professor, Medicine
Washington University School of Medicine, Saint Louis, MO

Dr. Prakash Gyawali is currently a Professor of Medicine, Director of Neurogastroenterology and Motility, and Program Director of Gastroenterology Fellowship Training at the Division of Gastroenterology, Washington University School of Medicine, St. Louis, USA. Dr. Gyawali's academic interests include gastrointestinal motility, acid peptic disorders including gastroesophageal reflux disease, and functional bowel disorders; he is also prominently involved in education and mentoring of students, residents, fellows and peers at all levels. He directs gastrointestinal motility centers affiliated with Washington University, and is involved in motility testing using high resolution manometry (esophageal and anorectal), esophageal ambulatory esophageal pH and impedance monitoring, and wireless pH monitoring. He is also part of several working groups and consensus committees involving esophageal physiologic testing, and has over 100 original publications. He has an extensive academic practice in esophagology and functional bowel disorders, and is actively involved in clinical research involving neurogastroenterology and motility.


Efi Kokkotou

Efi Kokkotou, MD, PhD
Associate Professor of Medicine
Harvard Medical School
Beth Israel Deaconess Medical Center, Boston, MA

Dr Kokkotou is Associate Professor of Medicine at Harvard Medical School and an Investigator and Director of Preclinical Drug Evaluation in Gastroenterology, Beth Israel Deaconess Medical Center. She is a non-practicing physician scientist with training in pediatrics, cancer biology, immunology and endocrinology (obesity and type 2 diabetes). She established her own lab in 2003 initially working on neuropeptide mediated brain-gut interactions. A particular focus of her research has been melanin-concentrating hormone (MCH), an appetite regulating hormone with established central effects. Dr Kokkotou’s initial experiments focused on the peripheral effects of MCH and revealed its immunomodulatory role in the context of intestinal inflammation. While work on MCH has progressed on early phase, proof-of concept clinical trials for inflammatory bowel disease (IBD) through drug repurposing, a more recent research interest in Dr Kokkotou’s lab has been drug screening using patient explants obtained by biopsy. The technique has been optimized for IBD-related drugs and has been shown to highly correlate with therapeutic responses using anti-TNF biologics. We envision applicability of this test in three major areas: a) pre-clinical proof-of-concept drug evaluation using human samples; b) as a precision medicine tool for selecting patients for phase 2 clinical trials; c) delivering personalized treatments in patients with IBD. From this line of investigation, which is highly translational, several partnerships have emerged between Dr Kokkotou’s lab and the pharmaceutical industry, some of them sponsored by NCATS and the Crohn’s and Colitis Foundation of America.


John Kuemmerle

John Kuemmerle, MD, AGAF
Charles M. Caravati Professor of Medicine; Chair Division of Gastroenterology, Hepatology and Nutrition
Virginia Commonwealth University, Center for Digestive Health, Richmond, VA

John F. Kuemmerle, MD, is chair for the Division of Gastroenterology, Hepatology and Nutrition and a professor of medicine and physiology with tenure at Virginia Commonwealth University (VCU). He graduated from the College of William and Mary and received his medical degree from Eastern Virginia Medical School. He completed internal medicine training and a NIH postdoctoral fellowship in gastroenterology at VCU.

His practice focuses on Crohn’s disease and ulcerative colitis. He offers his patients state-of-the-art chromoendoscopy and narrow-band imaging endoscopy for the early detection of colorectal cancers, and endoscopic therapy for stricturing Crohn’s disease. His patients can participate in a number of clinical research studies looking at outcomes in patients on biologic therapies for IBD and in studies performed in collaboration with Johns Hopkins University to determine the genetic causes of IBD. These include collaborative studies to understand the genetic susceptibility of African-Americans with inflammatory bowel disease.

Dr. Kuemmerle’s research focuses on the mechanisms of stricture formation in Crohn’s disease and translating that information into new ways to treat the disease. His research has been continuously funded for more than 20 years by NIH.

Dr. Kuemmerle is the editor of the American Gastroenterological Association’s gastrointestinal textbook, which is used by physicians throughout the U.S. to remain up to date about gastrointestinal disorders. He is also the online editor for Gastroenterology and Clinical Gastroenterology and Hepatology.


Kim BarretKim Barrett, PhD, AGAF
Distinguished Professor of Medicine
University of California, San Diego, La Jolla, CA

Dr. Kim Barrett, a native of the United Kingdom, obtained her B.Sc. and Ph.D. degrees from the Department of Chemistry at University College London. Following a post-doctoral fellowship at the National Institutes of Health, she joined the faculty of University of California, San Diego (UCSD) School of Medicine in 1985, and rose to her current rank of distinguished professor of medicine in the Division of Gastroenterology in 2015.

She has received a variety of honors for her research in gastrointestinal physiology, including the Bowditch and Davenport Lectureships of the American Physiological Society (APS) and the Bayliss-Starling Award from The Physiological Society (United Kingdom and Ireland). She has served on numerous committees for AGA, including a term as the Basic Science Councillor on the Governing Board. She is currently a member of the Publications Committee and a member of the advisory board for Gastroenterology. She is also a past-president of the APS and editor-in-chief of The Journal of Physiology.

From 2006-2016, she served as dean of the graduate division at UCSD in addition to her faculty appointment. In this role, she was a member of the senior academic management team of the institution and oversaw the recruitment and academic advancement for more than 5,000 masters and doctoral students. During her tenure as dean, she was the president of the Association of Graduate Schools of the American Association of Universities (2015-16).


Sheryl Pfeil

Sheryl Pfeil, MD, AGAF
Professor of Clinical Medicine
Medical Director, Clinical Skills Education and Assessment Center
The Ohio State University, Columbus, OH

 Sheryl Pfeil, MD, AGAF, is a gastroenterologist and faculty member in at the Ohio State University College of Medicine and Wexner Medical Center in Columbus, OH. She received her medical degree from the Ohio State University College of Medicine and completed her residency in internal medicine and her fellowship in gastroenterology at Case Western Reserve University/University Hospitals in Cleveland, OH. She has been on the faculty at Ohio State in the Department of Internal Medicine since 1990; she divides her time between clinical medicine and medical education.

She received the Distinguished Educator Award from the OSU College of Medicine for outstanding teaching and curriculum development and is a recipient of the Leonard Tow Humanism in Medicine award. She is regularly listed in, “Best Doctors in America.” She was a GI fellowship program director and is a faculty mentor in the OSU Institute for Teaching and Learning. Her other interests include simulation in medical education, and she is the medical director of the Clinical Skills Education and Assessment Center. 


Tushar Patel, MBChB

Tushar Patel, MBChB
Dean of Research
Mayo Clinic, Jacksonville, FL

Tushar Patel is the James C. and Sarah K. Kennedy Dean for Research at Mayo Clinic Florida. He is a Professor of Medicine and Professor of Cancer Biology at the Mayo Clinic College of Medicine and Science, and a consultant in the Department of Transplantation. He is a graduate of the University of Glasgow in Scotland, and completed clinical training with specialized training as a clinician-investigator at the Mayo Clinic.

His clinical expertise is in transplant hepatology and hepatobiliary neoplasia. His laboratory-based research program incorporates basic discovery studies aimed at understanding the molecular mechanisms of cancer formation in the liver and bile ducts, with translational research studies focused on the identification of novel biomarkers for cancer. These research studies are focused on the study of extracellular vesicles and non-coding RNA, and supported by the National Institutes of Health Common Fund through the Office of the NIH Director, National Center for Advancing Translational Sciences, National Institute of Diabetes & Digestive & Kidney Diseases and the National Science Foundation.

Dr Patel has published extensively in the field of liver diseases and liver cancers. He is an author or co-author of more than 140 peer reviewed articles that have been cited more than 13,000 times. He is an Associate Editor for Hepatology, Gene Expression and the Annals of Hepatology, and he has served as a peer reviewer for funding agencies in more than 10 countries. He is a Fellow of the American Gastroenterological Association as well as the American Association for Study of Liver Diseases, and is a recipient of the David C Balfour Award for meritorious research from the Mayo Alumni Association.


Vincent Yang

Vincent W. Yang, MD, PhD, FACP, AGAF
Chair of Medicine and Professor, Dept. of Medicine and Physiology and Biophysics
Stony Brook University School of Medicine, Stony Brook, NY

Dr. Yang is Simons Chair of Medicine and Professor of the Departments of Medicine and Physiology & Biophysics at Stony Brook University in Stony Brook, New York. An internationally renowned physician scientist in the field of gastroenterology, Dr. Yang’s research focus has been on identifying the causes and treatment of gastrointestinal malignancies including colorectal cancer. Born in Taipei, Taiwan, he received a B.Sc. degree from the Department of Agricultural Chemistry, National Taiwan University, Ph.D. from the Department of Biochemical Sciences of Princeton University and M.D. from Rutgers University Robert Wood Johnson Medical School. In New Jersey Dr. Yang received his clinical training in Internal Medicine followed by Gastroenterology at the Johns Hopkins University School of Medicine and was a faculty member in the Department of Medicine at Johns Hopkins between 1989 and 2001. He was appointed R. Bruce Logue Professor of Medicine and Director of the Division of Digestive Diseases in 2001 at Emory University School of Medicine in Atlanta, Georgia, where he also held the positions of Professor of Department of Hematology and Medical Oncology and Director of the Emory Epithelial Pathobiology Research Development Center, which was supported by a Digestive Diseases Center Grant from the National Institutes of Health. In 2011, Dr. Yang was recruited to Stony Brook University and brought with him a blend of clinical expertise, research acumen, teaching skills and leadership experience to his current position.

Dr. Yang's lab was the first to identify a number of Krüppel-like transcription factors (KLFs) and characterize their roles in the biology and pathobiology of the gut epithelium including stem cells and cancer. He has been principal investigator for many NIH-funded grants and authored or coauthored over 200 original scientific articles or chapters. He is a member of several honor societies including Alpha Omega Alpha Honor Medical Society, American Society for Clinical Investigation, Association of American Physicians, Fellow of the American College of Physicians, and American Gastroenterological Association Fellows, and was the recipient of the Distinguished Alumnus Award from his alma mater, Rutgers University Robert Wood Johnson Medical School. He was an invited speaker at over 30 national and international conferences and by numerous prestigious institutions residing int the United States, Europe, Japan, China, Hong Kong and Taiwan. He served as editor or was on the editorial boards of many professional journals, including Gastroenterology, the leading journal in the field, as well as numerous review panels or study sections at the National Institutes of Health and Veterans Administration, and more recently, the National Health Research Institute in Taiwan.


Xavier Llor

Xavier Llor, MD
Associate Professor
Yale University, New Haven, CT

Xavier Llor MD, PhD, obtained his medical degree from the Autonomous University Barcelona, Spain, trained in basic research and internal medicine at the University of Chicago, IL, and completed his GI fellowship at the University of Illinois at Chicago. He complemented his training with a PhD in molecular biology from the University of Barcelona.

A clinically active gastroenterologist, Dr. Llor’s research and clinical interests relate to colorectal cancer. He has a very active basic and translational research program mainly focusing on two different aspects of colorectal cancer: hereditary and familial forms, and disparities in colorectal cancer. This work has resulted in more than 60 scientific publications in this field. He has made seminal contributions to the field of Lynch syndrome diagnosis, as well as in the definition of other non-polyposis syndromic colorectal cancer cases. Some of his most recent work is bound to make a decisive contribution to the understanding of disparities in colorectal cancer.

Dr. Llor is the co-director of the Cancer Genetics and Prevention Program at Yale University and Smilow Cancer Center and he sees patients at Yale, New Haven, CT. He is a member of the AGA Leader- ship Council and chair of the International Committee. He is commonly invited to lecture in colorectal cancer genetics in the U.S. and abroad.