Principal Investigator Kenneth Croitoru

Dr. Kenneth Croitoru joined the Division of Gastroenterology at Mount Sinai Hospital in January 2008. He completed medical school at McGill University in 1981 and then trained in internal medicine and gastroenterology from 1982-1986. He went on to do post-doctoral training as an MRC Research Fellow in Mucosal Immunology with Dr. John Bienenstock at McMaster University.


Williams has a strong interest in the field of microbiota and its impact on human health. While completing a PhD in biotechnology and microbiology in France, he examined the probiotic and nutritional potential of lactic acid bacteria present in the microbiota of a fermented cereal based food using a molecular approach. At the University of Toronto and Samuel Lunenfeld Research Institute, he is currently investigating the effect of environmental factors and genotypes on human microbiome composition in the context of the prospective cohort Genetic, Environmental Microbial (GEM) project. His projects involve multiple skills and knowledge of various scientific fields, including advanced biostatistics, human physiology, human genetics, human microbiome, and human nutrition. His main project focuses on the effect of human genetics on microbiome composition and function.

Larbi is interested in the microbiological changes that may trigger diseases in human and animals, with a focus on the interaction between host and microbiome. As a postdoctoral fellow in the Croitoru lab, he is exploring the factors that may trigger Crohn’s disease in genetically susceptible individuals. This is made possible by mining the outstanding GEM project database, which includes data on first degree relatives (FDRs) of Crohn’s disease patients. Currently, his primary focus is on studying the interaction between FDRs genetics and their microbiome using a large bioinformatics and statistical toolset.

I am interested in the dynamic host-microbiota relationship. We cannot live without our microbes and our immune system works to distinguish symbiotic friend from pathogenic foe. How this happens, we are yet to understand. We have barely scratched the surface of understanding the complex bidirectional dependence between a host and their microbes.

My research is focused on understanding how perturbing the microbiota at different times can influence the mucosal immune system, and how this can lead to an altered susceptibility to colitis. I am interested in how the perturbation alters the bacterial community composition, the resilience of the community and how the immune system responds to the changing microbiota.

Mitra has been with Dr. Croitoru’s group since June 2011. She is currently working at the Central Processing Lab for the GEM Project at the University of Toronto. She is responsible for the preliminary processing and also managing and storing of all of the biospecimens collected by the study coordinators from sites worldwide.

Carmen recently joined the group in 2016. She is working on the GEM and GEMINI project at the University of Toronto for Dr.Croitoru. She is responsible for sample processing, and carrying out in vitro and in vivo experiments with samples obtained from human studies.

MSc, Cell and Systems Biology
University of Toronto, 2013
BSc, Cellular and Molecular Biology
University of Ottawa, 2009

The relationship between our health and microbial inhabitants is poorly understood and likely to be vast in its implications with Inflammatory Bowel Disease (IBD). IBD is used to collectively describe two distinct gastrointestinal tract diseases, Crohn’s Disease and Ulcerative Colitis. We are concerned in identifying biomarkers and developing new approaches for predicting, diagnosing and treating those with Crohn’s disease. We hope these biomarkers could be applied in a noninvasive manner to improve the lives of these patients.

Currently, I am comparing the status of potential biomarkers of the gut and blood in healthy versus diseased host states. The approaches I use include immune cell phenotyping by flow cytometry on innate and adaptive immune peripheral monocytes. I am assessing T-cells driving or regulating the immune response in chronic inflammatory states, and associated intracellular markers (IL-17a, TNF, and IFNg). Furthermore, we are interested in a unique innate T-cell subset, MAIT cells, which have been shown to be present in mucosal T-cells and react to microbial derived products.

Cristina currently works for the GEM Project, an international research study attempting to determine possible causes for Crohn’s Disease. She began working on the project as a summer student in 2014 and returned in August 2015 as a research assistant. Her duties include reviewing the health status of individuals enrolled in the GEM Project, supporting affiliate sites across the world and general study administration. She previously obtained a BA in Biology from Williams College and a MSc in Biomedical Sciences from Tufts University.

Heather MacAulay is a part of the GEM Project team working as a Research Coordinator. She joined the team after finishing a Bachelor of Science in Nutrition and Dietetics from Western University. She has also completed a Bachelor of Science in Human Kinetics from the University of Guelph. Heather has volunteered with, and made formal presentations to various population groups, working to develop food knowledge and healthy eating skills as well as increasing physical activity.

Harden is the Database Manager for Dr. Croitoru’s GEM Project database. He joined on to the program in 2016 He is responsible for data management, queries and quality assurance of the information entered by all of the sites.

My name is Nisha Ganeswaren and I have completed my Honours Bachelor of Science from the University of Toronto pursuing a double major in Health Studies and Biochemistry. Since July 2015, I have been working as part of the Global Project Office for the GEM Project. As part of the GEM Team, we are actively involved in ensuring that study procedures are adhered at all times. Furthermore, we are actively involved in providing support to the study sites based across the world.

Grace joined the team in 2015 as a clinical research coordinator for both Dr. Silverberg and Dr. Croitoru. She is involved in patient recruitment, collecting biological samples and questionnaire data entry. Her favourite part of the job is interacting with patients and listening to their stories. In her spare time, Grace enjoys sleeping, baking and spending time with friends and family.