Current Members

Marie-Claire Arrieta, Ph.D

Linkedin, ResearchGate, Pubmed


Originally trained as a medical microbiologist in San José, Costa Rica, Claire moved to Canada to pursue graduate studies. She completed M.Sc and PhD programs at the University of Alberta in Edmonton, Alberta. Her doctoral work explored the role of intestinal permeability (leaky gut) in the pathogenesis of inflammatory bowel disease. Through her work, she became very interested in the concept of the gut as the engine of diseases that occur in organs far away from the gut. Following this, she completed a postdoctoral fellowship in the laboratory of Dr. Brett Finlay's, a prominent molecular microbiologist that has pioneered many studies in the field of the human microbiome. During her postdoctoral stay, Claire studied the relationship between the gut microbiome, the gut's immune system and asthma, a disease of the lungs. Besides her time spent in research, Claire is also very interested in science communication to the public. She has written one public book (Let Them Eat Dirt), and is currently working on a second book (a children's book), as well as on a documentary film project.

Tahsin Ferdous, M.Sc


Tahsin Ferdous is a data analyst in the Department of Physiology and Pharmacology of the University of Calgary. In March 2020, she joined Dr. Marie-Claire Arrieta’s lab as a Biostatistician. There, Tahsin Ferdous is applying her expertise to perform statistical analysis of microbiome data and write supporting documents. She graduated from the University of Calgary with a Master of Science in Biostatistics. She received BSc (Hons) and another MSc degree in Statistics from Shahjalal University of Science & Technology, Sylhet, Bangladesh. She has applied statistical packages for simulated health data representing infectious persons in a sequence of hypothetical cities as well as RNA-sequencing data. She has a publication named “An Overview of RNA-seq Data Analysis” in the Journal of Biology and Life Science. She got “Queen Elizabeth II Diamond Jubilee Scholarship” and “Research scholarship at University of Calgary” in 2017. Tahsin Ferdous has great enthusiasm for working with microbiome data and in the field of Bioinformatics.

Andrea Guedez


Andrea Guedez is a Research Assistant for the BLOOM study within the Arrieta lab. She obtained her Bachelor of Medical Sciences with an Honors Double Major in Physiology and Pharmacology from the University of Western Ontario. It was here where Andrea developed a strong interest in pediatric and neonatal research, specifically in exploring the short and long-term effects of early life adversities on disease development. Her eagerness to learn led her to volunteer as a Clinical Research Assistant for the Development Neuroimaging lab, where she conducted MRI scans, managed sensitive situations and analyzed data for the Prenatal Alcohol Exposure study. As a member of the Arrieta lab, Andrea is looking forward to utilizing her experience and skills to positively contribute to the lab's success. Outside of the lab, Andrea enjoys hiking, the outdoors and getting together with family and friends.

Van Ortega, Ph.D



Van is an NSERC-funded Post Doctoral Fellow in the Arrieta lab. He obtained his PhD from the University of Alberta where his research focused on the potential for metal-based nanoparticles to inadvertently modulate immune responses, using model systems such as cell lines, primary cell cultures, and whole animals. Van also has a MSc from the University of Guelph where he examined changes in behavioral and physiological stress in fish when exposed to environmental contaminants. Van also has several years working as a risk assessment toxicologist in the turbid waters of environmental consulting. His interest in environmental health stems primarily from a fundamental curiosity in the science of environmental contamination and its effects on biological systems. For his PDF, Van is combing his experience in stress and immune research to investigate the role of commensal gut bacterial communities on the developmental outcomes of stress-axis systems that are integral for maintaining immune health and physiological homeostasis. When not in the lab, Van enjoys traveling, the outdoors and training for endurance races.

Shirin Moossavi, M.D, Ph.D

Website, Google Scholar


Shirin Moossavi is a CIHR Postdoctoral Fellow in the Department of Physiology and Pharmacology and Biomedical Engineering jointly supervised by Dr Marie-Claire Arrieta and Dr Amir Sanati-Nezhad. Shirin obtained her Medical Doctorate from Tehran University of Medical Sciences, Iran; her MSc in Genetic Manipulation and Molecular Biology from University of Sussex, UK; and PhD in Medical Microbiology from the University of Manitoba. She is the Early-Mid Career Ambassador of International Society of Microbial Ecology, the Founding Director of Microbiome and Microbial Ecology Interest Group at Universal Scientific Education and Research Network, and a contributor to Microbiome Digest.

Erik van Tilburg Bernardes, M.Sc

Linkedin, Pubmed, Google Scholar


After working for two years as the Research Associate in the Arrieta lab, Erik is changing his role in the lab and starting his Ph.D under Dr. Marie-Claire Arrieta's supervision. As the first addition to the lab, he has helped Claire immensely to set up the space and get the laboratory up and running. Erik holds both a Masters of Science in Microbiology and Infectious Diseases (2014-2017), from the University of Calgary, and a Bachelor in Pharmacy (2008-2014), by the Federal University of Alfenas (Unifal-MG, Brazil). His scientific career started in his undergraduate years in Brazil and later brought him to Calgary, working in different projects that aimed to study/identify alternative treatment options for the bacterial pathogen Pseudomonas aeruginosa. Erik's previous experience include different molecular, physiological and immunological techniques, which combined with his expertise in pharmacology and microbiology make him an invaluable asset for the team. His interests include the interactions between host and microorganisms, and Erik is keen to learn more on how these interactions shape the host's immune system and finally prevent/predispose individuals to developing diseases.

Jumana Samara, M.D

Website: ResearchGate


Jumana graduated from Medical School with a specialization in paediatrics after a residency-training program in Syria. Since 2015, she has been participating in a neonatal perinatal medicine program, taking care of sick newborn infants including preterm and low birth weight babies. She followed additional training in epidemiology at the University of Manitoba (2012-2013), and attended successfully the course of Quality Improvement and Patients Safety at the University of Calgary (2016-2017). One of the greatest challenges in her career is the infectious diseases targeting infants with weakened immune system. Her commitment toward her patients is to provide the best care, even beyond the discharge from Neonatal Intensive Care Unit. She recently started a Masters degree in Microbiology and Infectious Diseases with Dr. Arrieta. Her project aims to study the gut physiology and microbiome dynamics in preterm infants as well as the role of probiotics and how it contributes to childhood wellbeing.

Emily Mercer



Emily is a Masters student in the Arrieta lab, holding a Bachelor of Science in Microbiology from the University of Guelph (2012-2017). She completed her undergraduate thesis under the supervision of Dr. Emma Allen-Vercoe, a prominent gut microbiome researcher, which utilized 'Robogut' technology to explore gut microbial community assembly dynamics in naturally depleted ecosystems, such as in inflammatory bowel disease. Emily's interest in the gut microbiome initially stemmed from her passion for travel and experiences abroad, but further evolved as she became curious about the role of early childhood adversity in our lifelong health trajectories. In her Masters, Emily will examine the relationship between the early-life gut microbiome and the development of stress response networks in premature infants. Her research interests include microbial ecology, metabolomics, microbial community dynamics, host-microbe interactions, microbiome-based therapeutics and the gut-brain axis. Outside of the lab, Emily enjoys hiking, traveling, and the outdoors.

Mackenzie Gutierrez



Mackenzie is a fourth year undergraduate student majoring in Microbiology and Immunology at the University of British Columbia in Vancouver. As part of her co-op studies she has moved back to her home town of Calgary, and joined the Arrieta lab for 2 terms. Mackenzie has been involved in numerous projects in the lab, and is very interested in how the microbiome impacts immunological development, its contributions to the development of chronic diseases and how novel therapeutics can be used to manage such diseases. She has also been awarded the Alberta Innovates Summer Studentship award to fund her focus project exploring the impact of different microbiome populations on modulating the pathology of acute inflammation in the gastro intestinal tract.

Ali Javed


Ali is an undergraduate student at the University of Calgary, in his second year of the Biological Sciences program. He will be contributing to the Arrieta Lab as a summer undergraduate research student, and will be conducting an individual research project. Ali is very interested in cellular biology, as well as the effects of the environment in the development of human health and the immune system.

Julia Gorospe

Bilal Hafeez

Kaiden Jobin


Kaiden is a 3rd year Health Sciences student who is majoring in biomedical sciences. Starting in high school, Kaiden began working on a variety of projects in the microbiology field which were focused on bacterial diversity in the Canadian Arctic with a special interest in hydrocarbon degrading bacteria. Using his experience in metagenomics Kaiden is now interested in exploring fungal diversity within the gut microbiome and is specifically interested in the interplay between fungal diversity and the composition of the immune system. Outside of research, Kaiden loves to ski, hike and spend time with his family.

Kristen Kalbfleisch

LinkedIn, Pubmed


Kristen Kalbfleisch is the Lab Manager for the Arrieta lab. Here, she hopes to apply her dedication to integrity, HSE and her inquisitive mind to help the Arrieta Lab achieve their research goals. Kristen obtained her B.Sc. in Honors Biology from the University of Waterloo (2011), and returned for post-degree studies and a Teaching Assistant position centered in her passion - disease and microbiology - after spending some time teaching in Ilsan, South Korea. She spent some time in R&D at Sanofi Pasteur in Toronto, Ontario (through Seneca College) where she helped develop novel characterization methods and the teams first GMP protocol, within Analytical R&D. In 2018, Kristen made the difficult, but rewarding decision to move to Calgary, Alberta and now she calls the city, and the Arrieta lab home, applying her love of science to all aspects of her life including gardening, baking, fermenting, staying present in nature and living life to the fullest.