Dr. Dawn Bowdish: When the Gut Gets Old, Does the Immune System Follow?

1 day ago

3 min read

INTRODUCTION

Humans are exposed to dangerous microorganisms everyday. Although there are many potential pathogens that we encounter on a daily basis, we stay healthy due to our immune system; in particular, specialized blood cells called macrophages. As we get older, levels of inflammatory cytokines, damaged proteins and bacterial waste increases, this can lead to an increased risk of infection.

As we age, there are many changes to the body, one being our adaptive immune system is continuously remodelled by many extrinsic and intrinsic factors. Recent evidence has suggested that as we age, the immune system and gut microbiome undergoes changes in composition and function that correlates to “inflammaging”. The microbiome plays an essential role in regulating immune function and age-related change in diversity and composition.

These changes can alter our responses to vaccinations, affect intestinal barriers and increase exposure to microbials that stimulate the immune system. Dr. Bowdish’s lab focuses on understanding why and how the immune system ages and why older adults are more susceptible to respiratory infections and the long-term issues that occur after serious infections.

Dr. Dawn Bowdish

AFFILIATION

Dr. Dawn Bowdish is a professor and principal investigator of the Bowdish Lab in the Department of Medicine, Faculty of Health Sciences at McMaster University. She is also the executive director of the Firestone Institute for Respiratory Health, one of Canada’s largest respirology research institutes.

ACADEMIC & TEACHING BACKGROUND

Undergraduate study:

Dr. Bowdish completed her undergraduate studies at the University of Guelph in 1999, earning an Honours Bachelors of Science in Microbiology.

Graduate study:

She then completed her PhD in Microbiology and Immunology from the University of British Columbia in 2005. Following these degrees, she also completed a postdoctoral fellowship at the University of Oxford from 2005-2008.

Teaching and Researching Career:

Dr. Bowdish was then appointed to the Department of Pathology & Molecular Medicine at McMaster University in 2009. Where her lab is located in the M. G. DeGroote Centre for Living & Discovery.

RESEARCH INTERESTS

Dr. Bowdish started her lab at McMaster University in 2009. The Bowdish lab focuses on two major topics: how age and inflammation can increase one’s susceptibility to infection, and how the microbiome changes with age and how this develops into chronic inflammatory conditions.

When people age, the composition of the gut microbiome shifts. There is a loss of microbial diversity and a drop in beneficial short-chain fatty acid (SCFA)-producing bacteria and an overgrowth of pro-inflammatory bacteria. Additionally, aging weakens the intestinal epithelial barrier and thins the mucosal layer; this is also known as leaky gut. This breakdown lets bacterial components (i.e. lipopolysaccharides) and other live microbes enter the bloodstream. Overall, Dr. Bowdish and her team's vision is to understand why and how the immune system changes with age and aims to uncover why older adults are susceptible to respiratory infections.

AWARDS & LEADERSHIP

Research Canada Leadership in Advocacy Award (2025)
YWCA Hamilton Women of Distinction Award - Health and Recreation (2022)
McMaster Student Union Community Engagement Award (2019)
McMaster University Scholar (2018-2022)
Canada Research Chair in Aging & Immunity Tier 2 (2014-2019)
Best Teacher Award, Department of Pathology & Molecular Medicine (2014)
G. Jeanette Thorbecke New Investigator Award (2011)
ASPIRE, Pfizer Young Investigator Award for study of post-influenza pneumonia
in the elderly (2010)
JMH Junior Research Fellowship awarded by Linacre College at the University of Oxford (2006-2008)
Cangene Gold Award, Awarded by the Canadian Society of Microbiology for the highest ranked PhD thesis in Microbiology (2006)
Canada Graduate Scholarship awarded by the Canadian Institute of Health Research (2003-2005)

EPISODE OVERVIEW

In this episode, we follow Dr. Dawn Bowdish as she takes us along her academic journey and what has led her to her large array of achievements in the Department of Medicine. She shares how she got started in academia and how her passions have blossomed into the work she produces in the lab.