Researchers in the Vallance Lab
The Vallance Lab team is made up of Graduate and Undergraduate Students, Postdoctoral Fellows, Research Associates, and Lab Technicians.
Dr. Vallance completed his PhD training in gastrointestinal inflammation at McMaster University in Hamilton, Ontario, and then moved to Vancouver in 1999 to pursue his postdoctoral studies on disease-causing bacteria. Dr. Vallance was recruited to the University of British Columbia and BC Children’s Hospital as assistant professor in 2003. He has won numerous awards and currently holds the CHILD Foundation Chair in Pediatric Gastroenterology. Dr. Vallance’s research focuses on microbe-host interactions within the intestine, including defining the role that gut microbes play in causing chronic intestinal inflammation, as seen in Inflammatory Bowel Disease patients. Dr. Vallance is responsible for overseeing Gut4Health and fulfilling its mandate to become a key resource for microbiome researchers throughout Vancouver.
- Canada Research Chair in Pediatric Gastroenterology (Tier II) – 2004-2009
- CH.I.L.D. Foundation Chair in Pediatric Gastroenterology – 2013-ongoing
- Canadian Children Inflammatory Bowel Disease Network, CIHR and CH.I.L.D Foundation – 2013
Dr. Andy Sham
Gut4Health Project Manager
Dr. Andy Sham is the project manager for the Gut4Health Microbiome Core facility. Dr. Sham grew up in Vancouver, where he attended the University of British Columbia (BSc in Cell Biology and PhD in Experimental Medicine). His PhD research focused on bacterial pathogens and the interplay between bacteria and host at the gut lining to maintain intestinal health. He continued his research training as a Postdoctoral Research Fellow at Harvard Medical School where he studied how small molecules resolve inflammation in the lungs. After returning to Vancouver from Boston, he worked as a research scientist with a local biotech company where he led their research team in developing new drugs for the treatment of inflammatory bowel disease. Dr. Sham is responsible for conceiving and developing projects as well as the general operations for the core.
Dr. Hongbing Yu
My research has been focused on understanding the molecular and cellular mechanisms involved in infectious and immune diseases. During my initial training as a clinical microbiologist, I was fascinated by the complex molecular mechanisms underlying bacterial pathogenicity, and was motivated to pursue a PhD. For my doctoral research, I used genomics and proteomics approaches to systematically identify pathogenicity factors of Aeromonas hydrophila, an opportunistic pathogen in humans. To further study bacterial pathogenicity within the host, I chose to complete a postdoctoral fellowship in cell biology and innate immunity, exploring the interaction of autophagy with Salmonella Typhimurium. Over the past few years in Dr. Jacobson’s and Vallance’s labs, I used numerous in vivo techniques to define how the immune system controls mucosal defense against intestinal pathogens, such as Citrobacter rodentium (a surrogate organism for studying Enteropathogenic E. coli pathogenesis), and S. Typhimurium. My long-term research goal is to understand the role of immune system in governing host-microbe interactions in the gastro-intestinal tract.
Dr. Hyungjun Yang
I am a research associate specializing in mucosal immunology and animal model. I have been studying immune responses to bacterial infection at mucosal sites. Also, I’m interested in establishing an animal model for human-oriented pathogens. Currently, I am focusing on E. coli pathobionts isolated from UC patients and how pathobionts contribute to intestinal inflammation through the mucus barrier impaired by genetic or environmental factors.
Dr. Kevin Tsai
One of the most important tasks of our immune system is to distinguish between friends (self) and foes (not self) so that we can fend off invading pathogens while avoiding needless inflammation. This feature is best illustrated in the gut, where the immune system co-exists peacefully with billions of microbes, which are not self (or are they?) and may or may not be beneficial to us. How does the immune system know how and when to react to the non-self so that peace is maintained? What factors may contribute to the breakage of peace, leading to the development of inflammatory bowel disease and what can we do to restore the peace or even prevent the peace from being broken? Using animal models, 3D organoid cultures, microscopy, and flow cytometry, I investigate these research questions.
Dr. Larissa Celiberto
My background includes a BSc in Nutrition and Dietetics and a MSc in Food and Nutrition where I investigated the role of several probiotic bacteria in animal models of intestinal inflammation. My strong interest in the gut microbiome took me to Vancouver in 2016 to pursue a PhD in Experimental Medicine at the University of British Columbia in collaboration with the Sao Paulo State University. As a Postdoctoral Fellow, my research focuses on the relationship between the mucus overlying the intestinal epithelial cells and the gut microbiome. I am particularly interested in exploring the functions of mucus beyond its role as a protective barrier for the epithelial cells and how microbes-mucus interactions influence gut homeostasis and host defense. In addition to my work as a Postdoctoral Fellow, I also work as a Clinical Research Coordinator for the Gut4Health Microbiome Core. In this role, I assist clinicians and researchers to bridge the gap between cutting-edge research and practical applications to ensure that scientific advancements translate into tangible benefits for patients with gastrointestinal diseases. Outside the lab I enjoy various activities such as running, reading, watching Netflix, and spending quality time outdoors with my very active toddler.
- CDDW distinction poster award, Canadian Digestive Disease Week (2020)
- Travel award from BCCHR to attend the Canadian Digestive Disease Week (2020)
- Crohn’s and Colitis Canada Student Research Prize, Canadian Digestive Disease Week (2018)
- Latin American Studentship Award, Canadian Association of Gastroenterology (2016)
Dr. Paula Littlejohn
I am a Postdoctoral Research Fellow co-supervised by Dr. Michael Kobor and Dr. Bruce Vallance at the University of British Columbia & BC Children’s Hospital Research Institute. I received my PhD in microbiology & immunology from UBC in the lab of Dr. Brett Finlay, where I developed the first animal model to examine the impact of postnatal exposure to multiple micronutrient deficiencies on the gut microbiome and gut resistome (collection of antibiotic resistance genes and their mechanisms). I also created a mouse model to study a phenomenon known as the double burden of malnutrition and a maternal micronutrient deficient model. Presently, my work investigates the epigenetic signatures that contribute to inflammatory bowel disease (IBD) in children and how these might be used as clinical biomarkers for diagnosis, prognosis, and precision nutrition. As a wife and mom of 5, I enjoy spending time baking, walking, watching epic movies, and learning Mandarin with my family.
I am a recent (top-ranked) inaugural recipient of the TRIANGLE (TRaIning A New Generation of Researchers in Gastroenterology and Liver) AMPLIFY Postdoctoral Award supported by Crohn’s and Colitis Canada. I am an active member of the Canadian Black Scientists Network, Black Microbiology Association (USA), UBC Social Exposome Cluster and American Society for Nutrition.
In 2022, I moved back home to Vancouver to begin my doctoral studies at UBC in the Vallance lab after completing a BSc (Hons) and MSc in Microbiology at the University of Alberta. My doctoral research focuses on Escherichia coli pathobionts (commensal bacteria with pathogenic potential) isolated from ulcerative colitis (UC) patients and their interactions with the mucosal barrier. To investigate these interactions, I will use 3D organoid culture, organoid-derived monolayers, and relevant IBD mouse models. The goal of my research is to identify the mechanisms E. coli pathobionts use to cross the protective mucus layer, thus allowing them access to the colonic epithelium to promote and/or exacerbate disease.
- Canadian Institutes of Health Research Doctoral Research Award: Canada Graduate Scholarships (CIHR CGS-D)
Maira Jiménez Sánchez
Immune and inflammatory illnesses, such as inflammatory bowel disease (IBD) and multiple sclerosis (MS), are increasing in Western society due to changes in modern lifestyle: overuse of antibiotics and reduced exposure to sunlight, including ultraviolet B (UVB) light. My work focuses on how UVB light exposure on the skin affects gut homeostasis in mice. Specifically, we want to determine if UVB light exposure can prevent or treat inflammatory diseases such as IBD through vitamin D and the aryl hydrocarbon receptor.
- CONACYT (Mexican National Council of Science and Technology) PhD award, 2021
Pathogenic Escherichia coli and Campylobacter jejuni are among the most common bacterial causes of gastroenteritis around the world. Upon entering the host, these pathogens encounter the mucus layer overlining the surface of the GI tract that protects the epithelium. My research seeks to understand mucus-pathogen interactions, including the pathogens’ metabolic adaptation to the mucus niche to acquire nutrients in the competitive gut environment, and virulence strategies that the pathogens employ to overcome the mucus barrier and/or interact with the underlying epithelial cells to induce disease.
My research focuses on innate immunity at the intestinal epithelium. Using 3D organoid cultures, I am interested to see how enteric pathogens such as Salmonella enterica and pathogenic strains of Escherichia coli isolated from IBD patients can interact with the intestinal epithelium to trigger inflammatory responses and cell death. Additionally, I am also investigating the relationship between mucus secretion and cell proliferation at the intestinal epithelium.
Our group previously discovered that Toll like receptor 2 (Tlr2) expression by nonhematopoietic cells in mice played an important protective role in the Citrobacter rodentium model of infectious colitis. My research focuses on the novel role of Tlr2 signalling in intestinal epithelial cells by using organoids. Besides, we developed a novel in vitro model of C. rodentium infection to better study the role of IECs in promoting host defence during bacterial infection.
My research involves the development of novel bioinformatic pipelines to process and analyze gut microbiome data. I am involved in a fascinating project looking at the effect of diet supplementation on the gut microbiome in toddlers. To that end, I am interested in multi-omic data integration to gain a comprehensive understanding of the gut microbiome. In addition to my research, I also provide bioinformatic support to other lab members, helping them to analyze and interpret their own experimental data.
I am fascinated by the gut microbiome and its impact not only on IBD but also on various aspects of human health, including conditions that were once thought to be unrelated to the gut. Currently, my research focuses on investigating the therapeutic potential of fecal microbiota transplantation (FMT) in a mouse model deficient in mucin 2 and its protective effects against colitis. As a Master's student, I have gained practical experience in conducting in vivo mouse experiments and in vitro organoid culturing.
- CDDW poster prize, Canadian Digestive Disease Week (2023)
- Canada Graduate Scholarships – Master's (CGS M) award (2022)
I’m a gastroenterologist and microbiologist studying host-microbiota-pathogens interactions and their nutritional programs.
My role in the lab involves taking care of the daily operations. My area of research interest is to make various bacteria mutant strains for in vivo mouse experiments in order to study inflammatory response in the intestine.
Dr. Catherine Chan
Dr. Cathy Chan obtained her PhD from the University of Calgary where she studied membrane protein biochemistry of microbial systems. She continued her post-doctoral research at the University of British Columbia studying bacterial secretion systems and membrane proteomics. This was followed by a second fellowship studying anti-inflammation signalling pathways in mice as she wanted to learn more about animal models and immune systems. After an extended maternity leave with her amazing daughter, she joined a biotech company developing novel antibody-based therapeutics to combat animal gastrointestinal diseases. Her expertise in biochemistry and microbial systems is a valuable addition to the continued development in the at Gut4Health.
I work in isolating and culturing intestinal organoids from pediatric and adult patients with and without Inflammatory Bowel Disease.
One of the most innovative breakthroughs in stem cell research in the past decade has been the development of 3D organoid models. These in-vitro systems provide a biologically relevant model which highlights important characteristics of human organs which has allowed us to study cell-to-cell roles and interactions previously unknown. In the lab, I get to work with the newest techniques for establishing and maintaining enteric organoids from paediatric and adult tissue samples to provide a model to study Inflammatory Bowel Disease. I also support students with their research by assisting with the collection of mouse intestinal tissues which are used to grow enteric organoids for comparative model analysis. Additionally, I am responsible for the culture and care of other cell lines used in the lab to produce biological compounds. Finally, I ensure protocols are updated and followed by lab members to promote experimental repeatability and safety within the lab. Outside the lab I am a fan of bird watching and going for long walks, and I am always in search of a new podcast or audiobook to keep me entertained.
Past Team Members
Dr. Deanna Gibson
Dr. Marinieve Montero
Dr. Yanet Valdez
Dr. Lisa Mansson
Dr. Maryam Zarepour
Dr. Martin Stahl
Dr. HT Law
Dr. Vijay Morampudi
Dr. Joannie Allaire
Dr. Travis De Wolfe
Dr. Genelle Lunken
Dr. Kirk Bergstrom
Dr. Natasha Ryz
Dr. Shauna Crowley
Dr. Else Bosman
Dr. Kiran Bhullar
Dr. Ganive Bhinder
Dr. Mohammed Khan
Mr. Justin Chan
Technician and visiting scientist
Dr. Qin Yu
Ms. Tina Huang
Technician and Visiting Scientist
Dr. Alana Schick
Dr. Adi Eindor
Research in the Vallance Lab is supported by the following grants:
- CIHR Team Grant
Role of microbes in the pathogenesis of PIBD: From discovery, through causation, to novel treatments (2019)
Colonic goblet cells: Active players in host defense and mucosal protection? (2016)
Preserving gut defense by suppressing epithelial TLR/IL-1R signaling (2018)
Colonic goblet cells and mucus: Defining their roles in host defense and mucosal protection (2021)
Epithelial intrinsic inflammasomes direct host defense against gut microbes (2018)
- Genome Canada
Microbiome-based precision medicine in inflammatory bowel disease (2019)
Defining a novel skin-gut axis that controls immune and microbial homeostasis in the mammalian GI tract (2018)
- Crohn’s and Colitis Foundation
Bacterial pathobionts and ulcerative colitis: Causation to novel therapies (2019)
- Weston Family Foundation
Characterizing the Gut Microbiome in Patients during COVID-19 Infection (2020)