Zimmermann Research Lab

Dr. Ellen Zimmermann’s lab focuses on not only the molecular advances in IBD but also the social aspects that come along with the disease.

Dr. Zimmermann’s research includes:

  • Drug discovery – resveratrol, curcumin, THC, bacterial peptides
  • Student adjustment to college – focus groups, transition readiness
  • Non-invasive testing for Crohn’s disease – use of MRI, Big data studies of IBD medication use.

Dr. Zimmermann’s lab has developed strong relationships with multiple departments to ensure a holistic approach to her research. Dr. Zimmermann has collaborated with UF’s Integrative medicine staff, nutrition staff, along with UF radiologists and pharmacists. Dr. Zimmermann’s lab regularly collaborates with psychologists from Mt. Sinai, as well as the Israeli Drug Discovery group to provide the most cutting-edge research to a global audience.

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Dr. Ellen Zimmermann, MD

Dr. Ellen Zimmermann has 20 years experience in academic medicine at the University of Michigan. At the University of Michigan, Dr. Zimmermann built a vibrant basic and translational research program, built a national reputation in IBD and grew a clinical and research interest in the needs of college-aged patients with IBD. Dr. Zimmermann moved to the University of Florida in 2013, where she continued her passion of treating and researching IBD. Dr. Zimmermann is the current Vice Chair for Academic Affairs for the UF College of Medicine, along with being an active researcher and practicing physician.

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Chris Broxson, BS, BA

Christopher Broxson, B.A. chemistry; B.S. microbiology, is the laboratory manager for Dr. Ellen Zimmermann in the division of Gastroenterology at the University of Florida. Mr. Broxson began his research career as a junior chemist working in the material sciences developing high-strength ceramic fibers for use in heat-resistant composites. He later moved to biology and spent over a decade studying the synthesis and regulation of catecholamines in aging organisms. Finding himself drawn to the detailed analysis of biochemistry, he later moved to studying transcriptional regulation in non-canonical and secondary DNA structures such as telomeric G-quadruplexes.  After a brief stint studying renal biology, it was a natural progression to move to the mucosal immunology of the intestine when he joined the Zimmermann laboratory in 2013. Mr. Broxson has now been happily managing research laboratories as a senior biological scientist for over twenty years.

Synopsis of Current Research

Reducing or reversing intestinal fibrosis

Repeated rounds of inflammation associated with inflammatory bowel disease (IBD) can cause damage and scaring (fibrosis) to the walls of the intestine.  Over time, repeated build-up of fibrotic tissue can lead to a narrowing of the intestinal passageway known as fibrostenosis. Fibrostenosis is a serious complication, and it’s estimated that 50% of patients with Crohn’s disease (CD) and 10% of ulcerative colitis (UC) patients will develop fibrostenosis over their lifetime. Anti-fibrotic therapies are emerging in other fields, but little data are available to determine their potential usefulness in IBD. Our laboratory is studying established and novel anti-fibrotic agents with the goal of finding an effective treatment applicable to intestinal fibrostenosis.

Novel drug targeting

Our group is working with local and international collaborators to create a novel drug formulation which reduces unwanted absorption, and only becomes functional at sites of active inflammation.  Our approach is to utilize a family of enzymes know as phospholipases, which can break very specific (phospholipid) molecular bonds, and have been shown to be significantly elevated in the inflamed tissues of people with IBD.  By carefully designing drugs that are bound to phospholipids, a so called “pro-drug”, we may be able to reduce unwanted absorption and activity.  At sites of active inflammation, the abundant phospholipases could cleave the pro-drug, releasing the active portion, allowing highly specific targeting of diseased areas.

Medical marijuana

Our lab has begun controlled, reductionist studies to understand the basic biological effects of individual cannabis-derived chemicals as they relate to inflammation and fibrosis in the intestine.  Currently, our lab is using intestinally derived primary cell culture techniques to mimic healthy or diseased environments, and studying the mechanisms of cannabis exposure effects.


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Fares W. Ayoub, MD

A native of Jordan, Fares graduated with honors from the University of Jordan School of Medicine and is currently an internal medicine resident physician with the Department of Medicine at the University of Florida. At the Department of Medicine, Fares leads the gastroenterology interest group and is a senior member of the residency research & board preparation committee. He is a founding member of the UFHealth Shands Hospital proton pump inhibitor stewardship initiative and participates in the clinical peer review committee at the Malcolm Randall Veterans Administration Hospital. Fares was voted the 2018 Resident of the Year and has received the Emerging Liver Scholar Award by the American Association for the Study of Liver Diseases (AASLD). In his free time, Fares enjoys good architecture, coffee and music. After three years with the Zimmermann lab, Fares will be starting his gastroenterology fellowship at the University of Chicago.

Synopsis of Current Research

Fares’ work with the Zimmermann lab focuses on preoperative evaluation of Crohn’s disease patients with nutritional deficiencies. In collaboration with the departments of surgery and pharmacy, he has also investigated the effects of preoperative biologic therapy on operative outcomes. Fares enjoys predictive modeling and has presented work describing a model that predicts Crohn’s disease patients at risk for prolonged postoperative stays and postoperative complications. Currently, Fares supports other lab members with preliminary statistical analysis, clinical database management and poster design.

Recent Publications

  • Ayoub, F., Kamel, A. Y., Ouni, A., Chaudhry, N., Ader, Y., Tan, S., … & Glover, S. C. (2018). Pre-operative total parenteral nutrition improves post-operative outcomes in a subset of Crohn’s disease patients undergoing major abdominal surgery. Gastroenterology Report.
  • Kamel, A. Y., Ayoub, F., Banerjee, D., Chaudhry, N., Ader, Y., Tan, S., … & Iqbal, A. (2018). Effects of Preoperative Use of Biologic Agents on Operative Outcomes in Crohn’s Disease Patients. The American surgeon, 84(9), 1526.
  • Stoner, P. L., Kamel, A., Ayoub, F., Tan, S., Iqbal, A., Glover, S. C., & Zimmermann, E. M. (2018). Perioperative Care of Patients with Inflammatory Bowel Disease: Focus on Nutritional Support. Gastroenterology research and practice, 2018.

Oral presentations

  • Ayoub, F. & Kamel, A. & Chaudhry, N. & Iqbal, A. & Zimmermann, EM. & Glover, SC. & Tan, S. (June, 2018). Development of an Objective Prediction Model for Prolonged Postoperative Length of Stay in Crohn’s Disease Patients Undergoing Major Abdominal Surgery. Oral Presentation presented at: Digestive Disease Week 2018; Washington D.C, DC, USA.​

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Xi Wang, MPH

Xi Wang received her Bachelor’s degree from Xiangya School of Medicine, Central South University, China and her Master’s of Public Health in Epidemiology from Emory University.

Xi desires to become a health outcome researcher, with research interests in drug safety and comparative effectiveness, with an emphasis on pregnant women as well as chronically ill patients, specifically patients with inflammatory bowel disease.

Xi is currently a PhD student in the Department of Pharmaceutical Outcomes and policy at the University of Florida. In her doctoral dissertation, she is studying the spectrum of pharmaceutical management and disease burden of pregnant women with inflammatory bowel disease, as well as the safety of anti-TNFs as used in pregnant women with chronic inflammatory diseases in large population-based databases.


  • Wang, X., Winterstein, A. G., Li, Y., Zhu, Y., & Antonelli, P. J. (2018). Use of Systemic Antibiotics for Acute Otitis Externa. Otology & Neurotology, 39 (9), 1088-1094.doi:10.1097/mao.0000000000001955
  • Wang X, Zhu Y, Dave CV, Alrwisan AA, Voils SA, Winterstein AG. Trends of neonatal abstinence syndrome epidemic and maternal risk factors in Florida. Pharmacotherapy (2017) 37(7):806–13.10.1002/phar.1947
  • Goodin A, Delcher C, Valenzuela C, Wang X, Zhu Y, Roussos-Ross D and JD Brown. The Power and Pitfalls of Big Data Research in Obstetrics and Gynecology: A Consumer’s Guide. Obstetrical & Gynecological Survey 2017;72(11): 669-882.
  • Li, Y., Zhu, Y., Chen, C., Wang, X., Choi, Y., Henriksen, C., & Winterstein, A. G. (2017). Internal validation of Medicaid Analytic eXtract (MAX) data capture for comprehensive managed care plan enrollees from 2007 to 2010. Pharmacoepidemiology and Drug Safety. doi:10.1002/pds.4365
  • Zhu Y, Liu W, Li Y, Wang X, Winterstein AG. Prevalence of ADHD in Publicly Insured Adults. J Atten Disord. 2017;1087054717698815.
  • Ishiguro C, Wang X, Li L, Jick S. Antipsychotic drugs and risk of idiopathic venous thromboembolism: a nested case–control study using the CPRD. Pharmacoepidemiol Drug Saf. 2014;23:1168–75. doi:10.1002/pds.3699

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Isaac Molina, BS

Isaac Molina is the currently the IBD Patient Navigator for the UF Department of Gastroenterology. In addition to helping patients navigate through the twists and turns of healthcare, Isaac aides in various research projects that include analyzing college students with IBD’s transition to college and adult healthcare, as well as analyzing the outcomes of patients with Crohn’s Disease, with and without enteroenteric fistulas.

Isaac graduated from the University of Florida with his Bachelor of Science degree with a specialization in Biology, and a minor in Spanish in May of 2017. Isaac is currently working on obtaining his Masters of Business Administration here at UF’s Hough Graduate School of Business. Isaac looks forward to a career in healthcare administration.