ACGME Fellowship Program - Research Preceptors

Faculty members in the Section of Gastroenterology, Hepatology and Nutrition are currently involved in a number of basic and clinical research investigations on many different diseases and disorders. Below is a list of the research and clinical research faculty members and their interests.



Assistant Professor of Medicine
Core Faculty, Institute for Genomics and Systems Biology
Assistant Biologist, Biosciences Division, Argonne National Laboratory

During my postdoctoral studies I worked on the microbial ecology of the mammalian gastrointestinal tract in relation to antibiotic administration that led to my present research at the University. Recent advances in DNA sequencing technologies have provided unprecedented access to the genetic underpinnings of microbial function as the increase in sequencing depth (coverage) is quickly approaching the scale of sequence space (gene types and gene variants) embodied in these complex biological systems. My current work at the University is focused on using next-generation DNA sequencing technologies to study the metagenome of the microbiota of the GI tract as it relates to IBD and other GI diseases. I hold a joint appointment with the Institute for Genomics and Systems Biology (IGSB), as well as the Biosciences Division, at Argonne National Laboratory. Portions of this work are in collaboration with faculty in the Section of Gastroenterology at the University as well as with members of the Next Generation Sequencing Core and the Mathematics and Computer Science Division at Argonne as part of the NIH Human Microbiome Project.



Associate Professor of Medicine
Program Director,Transplant Hepatology Fellowship

Chronic hepatitis C is a major risk factor for end stage liver disease and is a leading cause of liver related morbidity and mortality worldwide. As our population ages, we are encountering an increasing number of patients with hepatitis C who are 65 years old and older. Since older patients are usually excluded from clinical trials evaluating safety and efficacy of hepatitis C therapies, clinicians have limited evidence to base treatment decisions in this population. My primary research interest involves studying hepatitis C treatment outcomes in this understudied population. In addition as part of the MacLean Center for Clinical Medical Ethics, I have also begun to work on ethical issues surrounding novel treatments for HCV.   



Associate Professor of Medicine

My research interests include investigations to understand factors that cause cells lining
the colon to become cancerous. Our laboratory is especially interested in how diet alters the susceptibility to develop colon cancer.  We are studying Western diets that promote colon cancer growth and fish oil diets that inhibit tumor development.  Dietary constituents have been shown to regulate growth factor signals. These growth factor signals are essential for healing colitis, but when chronically over-active, growth factor signals can promote tumor development.  Western diets increase growth factor signals, whereas fish oil diets suppress them. We believe these diet-induced differences in growth factor signals play central roles in the tumor-promoting versus tumor-inhibiting activities of diet. Recent studies have implicated colonic bile acids and bacteria in controlling these growth factors. Future research efforts will focus on understanding how bile acids and bacteria collaborate to enhance Western diet-related growth factor signals that promote colon cancer. 

We are also studying the role of inflammation (e.g. ulcerative colitis) in colon cancer development.  Ulcerative colitis, a chronic inflammatory disease of the colon, is an important risk factor for colon cancer. We are currently investigating two microRNAs important for cell differentiation that appear to be strongly down-regulated in ulcerative colitis.  Since these miRNAs have been shown to be colonic tumor suppressors, we speculate that their down-regulations contribute to ulcerative colitis-associated colon cancer.  In recent studies, we showed that dietary vitamin D increases these anti-tumor miRNAs in human colon. Thus vitamin D supplementation could offer a promising new dietary approach to prevent colon cancer in individuals with ulcerative colitis.



Martin Boyer Professor of Medicine
Associate Director for Academic Programs and Training in Gastroenterology
Director: The Martin Boyer Laboratories

We study intestinal microbes and viruses (the microbiome), particularly as they relate to health, digestive diseases (IBD) and other immune- and metabolic-related disorders. This relationship is fundamental to our health and, when perturbed, the consequences can be catastrophic.  The emergence of “Western” disorders like diabetes, obesity, metabolic syndrome, cancer and autoimmune disorders over the past century may be related to large shifts in the composite human microbiome caused by changes in the environment and life styles. In genetically susceptible individuals, these factors can potentially trigger events that disturb immune and metabolic homeostasis, initiating the development of disease. Our efforts are therefore directed towards gaining a better understanding of what factors are involved in the selection and assembly of intestinal microbes, and how they can be used to reshape the enteric microbiome to prevent and treat disease. We employ cutting edge approaches that include cultivation-dependent and –independent technologies for microbial analysis, genetically modified and gnotobiotic mouse models, metabolic and functional measurements, and advanced bioinformatic tools to investigate both host and microbiome.  The role of heat shock protein in maintaining intestinal and immune homeostasis Heat shock proteins (HSPs) are a highly conserved family of multifunctional molecules.

We also study the role of heat shock protein in maintaining intestinal and immune homeostasis. Heat shock proteins (HSPs) are a highly conserved family of multifunctional molecules. They play a role in mucosal cytoprotection, host-microbe interactions, innate immunity, cancer initiation and development, and in autophagy. Although many types are constitutively expressed, some, such as HSP70 and HSP25, are rapidly induced and preferentially synthesized under conditions of cellular stress and injury. Their physiological expression in the gut is maintained by cues and signals provided by the enteric microbiota.  In epithelial cells, their induction protects against toxic, oxidant, and thermal injury. Our laboratory, therefore, is investigating cellular and molecular mechanisms that mediate their cytoprotective effects in the context of mucosal inflammation. These studies involve correlations of molecular and biochemical techniques with physiological findings and imaging analysis.

These investigations involve extensive multi-disciplinary collaborations with other investigators in the Biological Science Division and at Argonne National Laboratory. He is currently supported by several grants from the NIH Human Microbiome Project, a NIH R37 MERIT award, a R01 award (on diet and the gut microbiome), and two NIH training grants (T32 and T35). In addition to his DDRCC duties, Dr. Chang is the Associate Director of Academic Affairs and Training in the section of Gastroenterology.



Professor of Medicine
Co-Director, Inflammatory Bowel Disease Center

My research interests are primarily involved in two major areas of clinical gastroenterology: inflammatory bowel diseases and health care outcomes. We have been studying both standard and experimental pharmacological therapies, including novel immune modulating agents, as they affect outcomes such as "quality of life" and the economics involved in the diagnosis and treatment of Inflammatory Bowel Disease. By applying the principles of biostatistics, epidemiology, and other integral components of health outcomes research, I hope to address some of the perplexing issues arising in the field of gastroenterology in the face of a rapidly changing health care system.



Professor of Medicine
Co-Director, Inflammatory Bowel Disease Center

My research broadly focuses on the ecology of microbes. Our group, which stands at the junction of computation, microbiology, and ecology, develops experimental approaches, algorithms, and software platforms to generate and make sense of high-throughput sequencing data, and to elucidate microbial community structure and/or functioning at the level of microbial marker genes, genomes, or pangenomes. My group and I create and utilize advanced visualization strategies and holistic approaches that combine multiple types of 'omics data to study complex medical and environmental questions. For more information on my research click here



Associate Professor of Medicine
Director, Center for Pancreatic Disorders
Director, Interventional Endoscopy – CERT

My research interests include genetic causes of chronic and recurrent acute pancreatitis and pancreatic cancer. I am also interested in the treatment (medical and endoscopic) of complications from pancreatitis, both acute and chronic, including minimally invasive endoscopic therapy for patients with severe necrotizing pancreatitis and walled off necrosis.



Professor of Medicine

The rewards of practicing at a leading Academic Hospital and Top ranked program in Gastroenterology offer me the opportunity to practice at the highest level of knowledge and technology that provides my patients with the comprehensive approaches to simple and complicated GI disorders.  My roles include Directing the Out-Patient GI Clinic and Clinical Teaching of our GI Fellows, Medical Residents and Students. Most recently, I led the transition of the GI Procedure Unit from the DCAM to the new Center for Care and Discovery. This move allows us to provide new innovative care to our patients in a new state of the art facility.



Professor of Medicine
Vice Chair of Research for the Department of Medicine

The pathogenesis of Inflammatory Bowel Disease arises from a dysregulated immune response to the intestinal bacterial microflora. We have developed a strong research interest in host-microbial interactions, in particular we are focusing our efforts on understanding how interactions between the microbiota and the host can lead to disease. The loss of immune tolerance is thought to be a major cause of development of destructive inflammatory responses in the intestine. This past year through two collaborative studies, we have identified a pathway that allows colonization by a human symbiont that promote immune regulation (Science 2011) and determined how diet by altering the bile can promote the bloom of pathobionts and disease (Nature, 2012). Last year, we had identified IL-15 and retinoic acid (a vitamin A metabolite) as promoting inflammatory immune responses to intestinal luminal antigens (Nature, 2011). This dysregulation may not only promote loss of tolerance to dietary antigens, but also explain loss of tolerance to the microbiota. We now have evidence that IL-15 overexpression leads to a dysbiosis with a bloom of pathobionts than can promote intestinal inflammation. Interesting in that regard, are reports indicating that Il-15 is overexpressed in the intestine of a subset of inflammatory bowel disease patients. We are now detemining the mechanisms by which Il-15 dysregulates the microbiota.

We have a very active Integrated Translational Research Core that allows clinicians and basic scientists to conduct translational studies in inflammatory bowel disease. We know now that human studies are required to determine new markers for diagnosis and prognosis, and develop new therapies. Our database continues to expand. We now collected clinical information, with their informed consent, on more than 1500 inflammatory bowel disease patients. Inflammatory bowel disease is a very heterogeneous disease. The goal of the Integrated Translational Research Core is to provide the tools for translational and clinical research at the highest level.

Finally, my laboratory continues to investigate the pathogenesis of celiac disease and is invested in developing a mouse model of celiac disease. Such a model is lacking and will be critical to develop new therapies and a vaccine that may prevent development of celiac disease in at risk children. Our goal is to provide alternative or complementary treatment to the gluten free diet and reduce the risk of celiac disease in children.



Assistant Professor of Medicine

My interests are in patients undergoing lung transplantation that are at risk of rejecting their transplanted lung(s) possibly as a result of gastroesophageal reflux disease (GERD).  We have the ability to test for both acid reflux and non-acid reflux at the University of Chicago’s Center for Esophageal Diseases, and I am collaborating with colleagues in the pulmonary section to further elucidate the role of GERD in lung transplantation.  Our ultimate goal is to determine early on prior to lung transplantation which patients may benefit from aggressive treatment of reflux disease either with acid suppressing medications or antireflux surgery.  Our hope is that identifying which patients would most benefit from these treatments would ultimately lead to improved patient outcomes after transplantation.  I have published recently in the area of ambulatory monitoring of gastroesophageal reflux disease, extraesophageal reflux disease, and therapeutic options for eosinophilic esophagitis.



Professor of Medicine
Director, Office of Community Engagement and Cancer Disparities, University of Chicago Comprehensive Cancer Center
Associate Investigator, University of Chicago Cancer Research Center
Faculty Affiliate, Center for the Study of Race, Culture and Politics
Faculty Affiliate, Center for Gender Studies

My interests are centered on women’s health, health disparities and community based participatory research in two distinct areas.  I have been an active public health advocate for reducing cancer disparities in Asian Americans.  My research in hepatitis B in Asian Americans has focused on disaggregating Asian subgroups and studying the different and unique barriers to liver cancer prevention and treatment in these populations.  I also study disparities in colorectal cancer prevention in minorities, with an emphasis on culturally competent educational interventions, which positively impact behavioral changes for colorectal cancer screening.  As a member/trainer of the Center for Cross Cultural Education, I am involved in developing measures to understand the impact of cultural competency on patient care.



Assistant Professor of Medicine

My clinical interests are primarily in caring for individuals with diseases with strong genetic risk factors including hereditary colorectal cancer and celiac disease. Currently, I see patients in the Cancer Risk clinic for evaluation of hereditary colorectal cancer syndromes (familial adenomatous polyposis and Lynch syndrome/HNPCC). In addition, I am a physician and board member of the Celiac Center at the University of Chicago.

The broad objective of my research program is the identification of genetic factors that contribute to risk of gastrointestinal diseases (including colorectal cancer, celiac disease and IBD) especially across different populations. In collaboration with Dr. Anna Di Rienzo, Professor in the Department of Human Genetics, I am investigating inter-individual and inter-ethnic differences in genetic and transcriptional responses to steroid hormones such as vitamin D and glucocorticoids. We are interested in how individuals respond to these hormones both in the peripheral blood and colon. Understanding these differences will help elucidate tissue-specific steroid hormone pathways as well as allow for individualized prediction of treatment response (e.g., glucocorticoid treatment in IBD or vitamin D treatment to prevent colorectal cancer). In collaboration with Dr. Nathan Ellis, Associate Professor at the University of Chicago Illinois, I am also studying genetic susceptibility factors to colorectal cancer specifically in African Americans who have the highest colorectal cancer incidence and mortality in the US. We have assembled a large series of patients from Chicago as well as North Carolina and are working to identify common as well as rare genetic variants that are associated with colorectal cancer in this population. Finally, I am interested in elucidating genetic and transcriptional signatures of celiac disease. To this end, I am collaborating with Dr. Bana Jabri on an experimental system to compare gene and gene expression differences in specific cell types involved in celiac disease pathogenesis.



Associate Professor of Medicine

Our research interest has two aspects: one is to understand the role of vitamin D in the development of colitis, and the other is to understand how vitamin D regulates innate immune response. We found that patients with Crohn’s disease or ulcerative colitis have marked reduction in epithelial vitamin D receptor (VDR) levels in the lesion. We demonstrated that the intestinal epithelial VDR has potent anti-colitic activity in experimental colitis models. The anti-colitic mechanism is to inhibit program cell death of colonic epithelial cells leading to protection of the mucosal epithelial barrier. We also showed that vitamin D attenuates macrophage inflammatory response to bacterial endotoxin and reduces sepsis-induced lung injury. Our research indicates that vitamin D limits inflammatory reaction by augmenting the negative feedback inhibitory pathway, which is mediated by microRNAs. This is a novel mechanism for vitamin D to control inflammation and reduce tissue damage.



Assistant Professor of Medicine
Associate Director, Adult Clinical Nutrition

I am actively investigating the effects of vitamin deficiency in patients requiring parenteral nutrition (intravenous feeding) and study the usefulness of fecal calprotectin in patients with inflammatory bowel disease. I also created a web-based mobile program to assess the utility of applications in managing inpatient hepatology patients. My work has been funded by the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).



Assistant Professor of Medicine

I am a hepatologist that specializes in the care of patients with liver disease, with a particular interest in hepatitis B, autoimmune and cholestatic liver diseases, and liver transplantation. I am also an active researcher with a focus on evidenced based medicine and patient centered outcomes.



Assistant Professor

My primary research interest focuses on cancer development in IBD.  Specifically, I am studying genetic expression patterns in premalignant and malignant lesions in patients with IBD. Because there are significant gaps in scientific knowledge as to why cancer develops in this high-risk population, prior efforts to prevent precancerous lesions have been generally unsuccessful. We propose to extend the knowledge we gain to develop new, less invasive markers to assess risk for cancer in patients with IBD.   A second goal is to identify and ultimately block molecular changes occurring in IBD-associated cancer in order to prevent the development of cancer in this high-risk population.  Because vitamin D deficiency is associated with several inflammatory conditions as well as non-IBD associated colon cancer, we are also interested in investigating the role of vitamin D in inflammation and IBD-associated cancer development. Along with several collaborators at the University of Chicago, we are currently embarking on a clinical study to investigate vitamin D in patients with ulcerative colitis.



Associate Professor of Medicine

Associate Program Director, Fellowship in Gastroenterology, Hepatology and Nutrition My research is focused on viral hepatitis and hepatocellular carcinoma. I am currently investigating the use of biomarkers to assess both disease response and progression.



Associate Professor of Medicine
Program Director, Fellowship in Gastroenterology, Hepatology and Nutrition

My research interests are primarily focused in the study of liver diseases. This past year, I have been involved with clinical trials using novel treatments for several liver conditions including hepatic encephalopathy, hepatorenal syndrome and primary biliary cirrhosis. In addition, I have been involved in an IBD project studying the intestinal microbiome in ulcerative colitis after colon resection. We have rapidly expanded our liver transplantation services and I am very active in the clinical efforts of our hepatology division. My clinical practice also includes general gastroenterology, endoscopy and IBD. I remain heavily involved in the training and education of GI fellows and will be assuming the role as the Program Director for the Gastroenterology Fellowship in July 2012.



Clinical Associate of Medicine

He continues to research on the ability of Mitomycin –C to prolong the interval between dilations in patients with strictures of the gastrointestinal tract.  He continues his research on the effect of sulindac in suppressing the formation of precancerous adenomatous polyps of the colon and its relation to the PIK3CA mutation.



Professor of Medicine
Chief, Section of Gastroenterology
Co-Director, Inflammatory Bowel Disease Center
Associate Faculty, MacLean Center for Clinical Medical Ethics
Associate Investigator, University of Chicago Cancer Research Center
Medical Advisor, GIRF Associates’ Board

My clinical practice remains focused almost exclusively on patients with inflammatory bowel disease.  My research continues to focus on clinical outcomes in patients with IBD, and advanced technologies for screening and diagnosis in inflammatory bowel disease and prevention of colorectal cancer in these high risk patients.  We have investigated the role of inflammation and cancer or hospitalizations in our patients.  In addition, we will be one of the only groups in the world to study fecal transplantation as a potential treatment for ulcerative colitis and are also collaborating on novel studies of cancer detection and prevention in ulcerative colitis.



Assistant Professor of Medicine

I focus on a patient oriented approach when providing treatments and care for patients with inflammatory bowel diseases. I utilize my knowledge, experience, and the latest evidence when providing options, and always make decisions together with the patient.

My research involves advancing the effectiveness of combination therapy with an immunomodulator in anti-TNF treated inflammatory bowel disease patients, elucidating the efficacy and safety of natalizumab in anti-TNF refractory Crohn's disease, and analyzing the long term outcome of patients with microscopic colitis. Some of the studies have already led to or are in preparation for publication, and I strongly believe that the outcome of my research would contribute to improved understanding and care of the diseases.



Professor of Medicine
Director, Adult Clinical Nutrition

My research interests are directed towards clinical applications of interventional endoscopy techniques for the early detection, diagnosis and treatment of disorders of the pancreatic and biliary systems and tumors of the gastrointestinal luminal tract, with a focus on modalities such as endoscopic ultrasound, ERCP, and endoscopic ablative technologies. Current clinical research interests include novel therapeutic modalities for early esophageal cancer, studies evaluating the endoscopic teaching process, and decision modeling for a variety of complex endoscopic/surgical conditions. Further research will focus on endoscopic device designs as they pertain to tissue ablation and/or guided visualization study of their endoscopic therapeutics or imaging potential in the GI lumen, pancreatic, or biliary tracts.



Assistant Professor of Medicine
Director, Adult Clinical Nutrition

My research interests are in optimizing the care and outcomes of patients who are hospitalized with gastrointestinal bleeding. Through my research, I have described risk factors for adverse outcomes in patients hospitalized with lower gastrointestinal bleeding, as well as for patients presenting with gastrointestinal bleeding while on anticoagulant medications. I also serve as the sectional quality improvement director, and have active projects focused on improving the quality of colorectal cancer screening.



Associate Professor of Medicine
Director, Endoscopic Ultrasound and Advanced Endoscopy Training
The Center for Endoscopic Research and Therapeutics (CERT)

My research interests are directed towards clinical applications of interventional endoscopy techniques for the early detection, diagnosis and treatment of disorders of the pancreatic and biliary systems and tumors of the gastrointestinal luminal tract, with a focus on modalities such as endoscopic ultrasound, ERCP, and endoscopic ablative technologies. Current clinical research interests include novel therapeutic modalities for early esophageal cancer, studies evaluating the endoscopic teaching process, and decision modeling for a variety of complex endoscopic/surgical conditions. Further research will focus on endoscopic device designs as they pertain to tissue ablation and/or guided visualization study of their endoscopic therapeutics or imaging potential in the GI lumen, pancreatic, or biliary tracts.



Professor of Medicine

Over the past year, Dr. John Renz (Surgical Director of Liver Transplantation) and I continued to integrate our efforts in revitalizing and growing our Liver Transplant Program. We have made significant progress in moving many quality metrics of the program to better, if not top, places amongst the programs in the city. Our program continues to have excellent one-year graft and patient survival rates, a declining waitlist mortality rate, and the highest transplant rate in Chicago.

My research interest lies mostly in hepatitis C and liver transplantation. Our program was one of the very first few transplant programs in the country to embark on the early use of telaprevir (a newer protease inhibitor) in liver transplant recipients with recurrent hepatitis C within a year of its FDA approval. Recurrent hepatitis C has been poorly responsive to the standard regimen of pegylated interferon and ribavirin, but the addition of telaprevir holds promise for a better response. However, the use of telaprevir in this patient population has been tempered by the potential risks imposed by a significant drug-drug interaction with immunosuppressive agents. I am pleased to say that with meticulous monitoring, we have shown that telaprevir, plus interferon and ribavirin, is safe and successful in eradicating hepatitis C in this difficult-to-treat patient population. In keeping with the large strides being made in the rapidly evolving field of hepatitis C treatment, we are also now offering an interferon-free treatment regimen for our transplant recipients within the context of a clinical trial.



Professor of Medicine
Professor of Surgery
Professor of the Cancer Research Center
Director, Center for Endoscopic Research and Therapeutics (CERT)

2011 was a very busy year for the CERT. One of the biggest accomplishments for the year was the successful recruitment two stellar clinical faculty, Dr Uzma Siddiqui from Yale, who has joined us as Associate Professor of Medicine and Director of the Endoscopic Ultrasound program and the advanced interventional fellowship and Dr Andres Gelrud from the University of Pittsburgh who will direct the University of Chicago Center for pancreatic diseases. Both Uzma and Andres are nationally recognized experts in their field and talented interventional endoscopists.

Being one of the major centers in the Midwest interested in Barrett’s esophagus and early esophageal cancer we have been able to create a large repository of clinical material for research. In collaboration with our own Thoracic Oncology group lead by Dr. Ravi Salgia, we have established a large tumor tissue resource that includes various human esophageal cancer tissue including Barrett’s metaplasia and dysplasia (400-500 samples) which have corresponding clinical data that can be used to correlate experimental findings with clinical characteristics and available survival data. This has allowed his lab to identify that EphB4 (part of the family of tyrosine kinase receptors) is overexpressed and have increased gene copy numbers in esophageal tumors as well as being involved in enhanced motility and migration. This finding has potentially exciting applications for targeted biological therapies for esophageal cancer.

Finally, in the clinical therapeutic arena, we continue to develop techniques and technology for endoluminal resection (minimally invasive surgery through the endoscope) and currently part of the national task force involved in introducing endoscopic submucosal dissection techniques in the US.