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Zane Cohen Centre for Digestive Diseases
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Dr. Kenneth Croitoru

Clinician Scientist /Gastroenterologist

Dr. Ken Croitoru is an internationally recognized clinician-scientist, gastroenterologist, and academic leader dedicated to advancing the understanding, prediction, and prevention of inflammatory bowel disease (IBD).

As the lead investigator of the landmark GEM Project (Genetics, Environmental, Microbial Project), launched in 2008, Dr. Croitoru pioneered one of the world’s only large prospective studies designed to identify the earliest biological and microbial changes that occur before Crohn’s disease develops. Under his leadership, the GEM Project has produced transformative discoveries, including predictive gut microbiome signatures and blood-based immune markers capable of identifying Crohn’s disease risk years before symptoms emerge.

Dr. Croitoru currently serves as:

• Professor, Department of Medicine and Department of Immunology at University of Toronto

• Holds a Canada Research Chair Tier 1 in Inflammatory Bowel Diseases

• Staff Gastroenterologist at Sinai Health 

• Scientist at the Lunenfeld-Tanenbaum Research Institute 

• Associate Staff Gastroenterologist at University Health Network 

Prior to joining the University of Toronto, he held numerous academic and leadership appointments at McMaster University and Hamilton Health Sciences, including Director of the Gastroenterology Residency Training Program and Associate Director of the Division of Gastroenterology.

Over more than three decades, Dr. Croitoru has been recognized nationally and internationally for his scientific leadership and contributions to gastroenterology, immunology, and translational medicine. Some of his honours include:

• Career Scientist Awards from the Ontario Ministry of Health (1991–2001) 

• IBD Scientist Award and Research Leadership Award from Crohn's and Colitis Canada 

• Ivan T. Beck Memorial Lectureship Award from the Canadian Association of Gastroenterology (2017) 

• Tier 1 Canadian Research Chair in Inflammatory Bowel Diseases (2019–2026) 

• Eaton Scholar Researcher of the Year (Basic Science), University of Toronto (2022) 

• Richard N. Fedorak Award of Distinction for Mentoring in IBD (2024) 

Beyond his research achievements, Dr. Croitoru is widely respected for his mentorship, collaborative leadership, and compassionate approach to patient care. Through ongoing international collaboration, continuous medical education, and innovative translational research, he remains committed to improving the lives of patients and families affected by inflammatory bowel disease while helping shape the future of preventive gastroenterology.

Centre
Sinai Health Centre for Inflammatory Bowel Disease
Zane Cohen Centre for Digestive Diseases
Lunenfeld-Tanenbaum Research Institute

Contact

Mount Sinai Hospital

Joseph and Wolf Lebovic Health Centre

437-600 University Av.

Toronto, ON   M5G 1X5

Phone: 416-586-4800 ext. 7454

Fax: 416-586-4747

E-mail: drcroitoru.clinic@sinaihealth.ca

Research Office

Croitoru lab

Lunenfeld-Tanenbaum Research Institute

60 Murray St

Toronto, ON M5G 1X5

Publications

  • Vallance, B.A., Croitoru, K. and Collins, S.M.  T lymphocyte-dependent and -independent intestinal smooth muscle dysfunction in the T. spiralis infected mouse.  American Journal of Physiology 38:G1157-1165, 1998.
  • Xing, Z., Wang, J., Croitoru, K. and Wakeham, J.  Protection by CD4 or CD8 T cells against pulmonary Mycobacterium bovis Bacillus Calmette-Guerin infection.  Infection and Immunity 66:5537-5542, 1998.
  • Radojevic, N., McKay, D.M., Merger, M., Vallance, B.A., Collins, S.M. and Croitoru, K.  Characterization of enteric functional changes evoked by In vivo anti-CD3 T cell activation. American Journal of Physiology: Regulatory, Integrative and Comparative Physiology 45:R715-R723, 1999.
  • Bo, J., Jordana, M., Xing, Z., Smaill, F., Snider, D.P., Borojevic, R., Steele-Norwood, D., Hunt, R.H. and Croitoru, K.  Replication defective adenovirus infection reduces Helicobacter felis colonization in the mouse in an interferon-? and IL-12 dependent manner.  Infection and Immunity 67:4539-4544, 1999.
  • Merger M, Viney JL, Borojevic R, Steele-Norwood D, Zhou P, Clark DA, Riddell R, Maric R, Podack ER, Croitoru, K.  Defining the roles of perforin, Fas/FasL, and tumour necrosis factor alpha in T cell induced mucosal damage in the mouse intestine.  Gut 51:155-163, 2002.
  • Steinhart, A.H., Feagan, B.G., Wong, C.J., Vandervoort, M., Mikolainis, S., Croitoru, K., Seidman, E., Leddin, D.J., Bitton, A., Drouin, E., Cohen, A. and Greenberg, G.R. Combination Budesonide and antibiotic therapy for active Crohn’s disease: a randomized controlled trial. Gastroenterology 123(1):33-40, 2002.
  • Streutker, C.J., Bernstein, C.N., Chan, V.L., Riddell, R.H. and Croitoru, K.  Detection of species-specific Helicobacter ribosomal DNA in intestinal biopsy samples from a population-based cohort of patients with ulcerative colitis.  Journal of Clinical Microbiology 42(2):660-664, 2004.
  • Zhou, P., Borojevic, R., Streutker, C., Snider, D., Liang, H. and Croitoru, K.  Expression of dual TCR on DO11.10 T cells allows for ovalbumin-induced oral tolerance to prevent T cell-mediated colitis directed against unrelated enteric bacterial antigens.  Journal of Immunology 172:1515-1523, 2004.
  • Soderholm, J.D., Streutker, C., Yang, P.-C., Paterson, C., Singh, P.K., McKay, D.M., Sherman, P.M., Croitoru, K. and Perdue, M.H.  Increased epithelial uptake of protein antigens in the ileum of Crohn’s disease mediated by tumour necrosis factor a.  Gut 53:1817-1824, 2004.
  • Zhou, P., Streutker, C., Borojevic, R., Wang, Y. and Croitoru, K.  IL-10 modulates intestinal damage and epithelial cell apoptosis in T cell-mediated enteropathy.  American Journal of Physiology-Gastrointestinal and Liver Physiology, 287:G599-G604, 2004.
  • Mow, W.S., Landers, C.J., Steinhart, A.H., Feagan, B.G., Croitoru, K., Seidman, E., Greenberg, G.R. and Targan, S.R. High-level serum antibodies to bacterial antigens are associated with antibiotic-induced clinical remission in Crohn’s disease: a pilot study.  Digestive Diseases and Sciences 49:1280-1286, 2004.
  • Croitoru, K. and Zhou, P.  T-cell-induced mucosal damage in the intestine.  Current Opinion in Gastroenterology 20:581-586, 2004.
  • Panaccione, R., Fedorak, R.N., Aumais, G., Bernstein, C.N., Bitton, A., Croitoru, K., Enns, R., Feagan, B., Fishman, M., Greenberg, G., Griffiths, A., Marshall, J.K., Rasul, I., Sadowski, D., Seidman, E., Steinhart, H., Sutherland, L., Walli, E., Wild, G., Williams, C.N. and Zachos, M.  Canadian Association of Gastroenterology Clinical Practice Guidelines: the use of infliximab in Crohn’s disease.  Canadian Journal of Gastroenterology 18:503-508, 2004.
  • Shin, J.L., Teitel, J., Swain, M.G., Bain, V.G., Adams, P.C., Croitoru, K., Peltekian, K., Schweiger, F., Simons, M.E. and Heathcote, EJ.  A Canadian multicenter retrospective study evaluating transjugular liver biopsy in patients with congenital bleeding disorders and hepatitis C: Is it safe and useful?  American Journal of Hematology 78:85-93, 2005.
  • Alvarez, D., Swirski, F.K., Yang, T-C., Fattouh, R., Croitoru, K., Bramson, J.L., Stämpfli, M.R. and Jordana, M. Inhalation tolerance is induced selectively in thoracic lymph nodes but executed pervasively at distant mucosal and non-mucosal tissues. Journal of Immunology 176:2568-2580, 2006.
  • Bharhani, M.S., Borojevic, R., Basak, S., Ho, E., Zhou, P. and Croitoru, K.  IL-10 protects mouse intestinal epithelial cells from Fas-induced apoptosis via modulating Fas expression and altering caspase-8 and FLIP expression.  Am J Physiol Gastrointest Liver Physiol 291:820-829, 2006.
  • Mauro, M., Radovic, V., Zhou, P., Wolfe, M., Kamath, M., Bercik, P. Croitoru, K. and Armstrong, D.  13C urea breath test for Helicobacter pylori: Determination of the optimal cut-off point in a Canadian community population.  The Canadian Journal of Gastroenterology 20:770-774, 2006.
  • Chatterjee A, Swain MG, Lee SS, Bain VG, Peltekian K, Croitoru K, Adams PC, Kaita K, Teitel J and Heathcote EJ.  Induction versus noninduction antiviral therapy for chronic hepatitis C virus in patients with congenital coagulation disorders: a Canadian multicentre trial.  The Canadian Journal of Gastroenterology 21(2):91-95, 2007.
  • Wu L, Feng BS, He SH, Zheng PY, Croitoru K, Yang PC. Bacterial peptidoglycan breaks down intestinal tolerance via mast cell activation: the role of TLR2 and NOD2. Immunology and Cell Biology. Oct; 85(7):538-45, 2007.
  • Panancionne, R., Fedorak, R. N., Aumais, G., Bernard, E. J., Bernstein, C. N., Bitton, A., Croitoru, K., Dieleman, L. A., Enns, R., Feagan, B. G., Franchimont, D., Greenberg, G. R. Griffiths, A. M., Marshall, J. K., Pare, P., Patel, S., Penner, R., Render, C., Seidman, E., Steinhart, A. H. Review and Clinical Perspectives for the use of Infliximab in Ulcerative Colitis.  The Canadian Journal of Gastroenterology 22(3):261-272, 2008.
  • Verdu, E.F., Bercik, P., Huang, X.X., Lu, J., Al-Mutawaly, N., Sakai, H., Tompkins, T. A., Croitoru, K., Tsuchida, E., Perdue, M., Collins, S. M.  The role of luminal factors in the recovery of gastric function and behavioral changes after chronic Helicobacter pylori infection.  American Journal of Physiology: Gastrointestinal and Liver Physiology.  2008 Oct; 295(4):G664-70.
  • Heriazon A, Zhou P, Borojevic R, Foerster K, Streutker CJ, Ng T, Croitoru K. Regulatory T cells modulate staphylococcal enterotoxin B-induced effector T-cell activation and acceleration of colitis. Infect Immun. 2009 Feb;77(2):707-13. Epub 2008 Dec 8.
  • Stearns JC, Lynch MD, Senadheera DB, Tenenbaum HC, Goldberg MB, Cvitkovitch DG, Croitoru K, Moreno-Hagelsieb G, Neufeld JD. Bacterial biogeography of the human digestive tract. Scienctific Reports. 1:170, 2011.
  • Jones NL, Croitoru K, Vanner S, Soni R, Hope L. Research Topics in Gastrointestinal Disease: a report on the 10th meeting and an announcement of the 11th meeting. Canadian Journal of Gastroenterology. Aug;25(8):449-50, 2011.
  • Forster K, Goethel A, Chan CW, Zanello G, Streutker C, Croitoru K. An oral CD3-specific antibody suppresses T-cell-induced colitis and alters cytokine responses to T-cell activation in mice. Gastroenterology. Nov;143(5):1298-307, 2012.
  • Weizman AV, Ahn E, Thanabalan R, Leung W, Croitoru K, Silverberg MS, Steinhart AH, Nguyen GC. Characterisation of complementary and alternative medicine use and its impact on medication adherence in inflammatory bowel disease. Alimentary Pharmacology and Therapeutics. Feb;35(3):342-9, 2012.
  • Leung W, Malhi G, Willey BM, McGeer AJ, Borgundvaag B, Thanabalan R, Gnanasuntharam P, Le B, Weizman AV, Croitoru K, Silverberg MS, Steinhart AH, Nguyen GC. Prevalence and predictors of MRSA, ESBL, and VRE colonization in the ambulatory IBD population. Journal of Crohns and Colitis. Aug;6(7):743-9, 2012.
  • Waterman M, Xu W, Dinani A, Steinhart AH, Croitoru K, Nguyen GC, McLeod RS, Greenberg GR, Cohen Z, Silverberg MS. Preoperative biological therapy and short-term outcomes of abdominal surgery in patients with inflammatory bowel disease. Gut. Mar;62(3):387-94, 2013.