As a clinician scientist Keshavarzian has been studying the impact of environmental factors (stress, alcohol, sleep and circadian disruption) on intestinal barrier function host/microbe interaction that promote intestinal and systemic (gut-derived) inflammation leading to initiation and/or progression of inflammatory disorders including inflammatory bowel disease, irritable bowel syndrome, food allergy, metabolic syndrome, alcoholic and non-alcoholic steatohepatitis and Parkinson’s disease. He has contributed to over 380 peer-reviewed published articles and book chapters with an h-index of 90. He has been doing basic science, translational and clinical research focused on liver and GI tract for almost three decades and the PI on multiple R01, R-21, RC3 and SBIR grants collaborating with many investigators. He was one of the first investigators to report the key role of oxygen free radicals in tissue injury in inflammatory bowel disease and alcohol-induced disruption of the intestinal barrier in alcoholic liver disease in the 1980s and one of the first investigators to begin to focus on the role of intestinal microbiota in health and disease in alcoholism, IBD, cancer, HIV and Parkinson. He has been studying the effects of circadian rhythm disruption on intestinal disease since 2007 and one of the early investigators to examine the effects of circadian disruption on the effects of alcohol and to report the negative impact of sleep and circadian disruption in IBD.

Keshavarzian was instrumental in starting the mentoring program at Rush University Medical Center and was honored with several Teaching and Service Awards and with the Excellence in Mentoring Award and continues to mentor at Rush, nationally and internationally. He is involved with numerous local/regional and national committees and gastroenterology associations and current reviewer for Medical Research Council of UK, NIH, Foundations, ACG and AGA research review panels. He has served in multiple ACG committees in the last three decades and was the ACG governor for the state of Illinois for two terms.