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Lorraine Chalifour

Lorraine Chalifour, PhD

Molecular & Regenerative Medicine

Cardiac surgery, Echocardiography, Gut microbiome and metabolome, Inflammation, Myocardial infarction, Resistant starch diet, Sex-dependent response, Total western diet
  • Senior Investigator and Associate Director of Training , Lady Davis Institute for Medical Research
  • Associate professor, Experimental Medicine, Faculty of Medicine and Health Sciences, McGill University
  • Associate Dean, Graduate and Postdoctoral Studies, Dental Medicine and Oral Health Sciences, Kinesiology and Physical Education, Management, Medicine and Health Sciences, McGill University

Contact details

(514) 340-8222 ext. 24295


On average, ~ 38,000 Canadians per year experience a cardiac surgery. Serious adverse events requiring acute care or hospital readmission occur in up to 25% of coronary bypass graft patients. This indicates that some key components, which control recovery, are being overlooked. Few studies have focused on the effects of surgery on the microbiota and metabolome and fewer still have investigated interventions to maintain gut health. Our research asks how surgery influences the gut microbiome such that recovery is impaired.

Our overarching hypothesis is that surgery induces a gut dysbiosis which contributes to greater systemic inflammation and impaired recovery. Our goal is to characterize the gut dysbiosis with time post- cardiac surgery, define recovery-promoting microbiome profiles and test intervention strategies to promote the resident microbiota such that gut health and cardiac structure/function are improved.

Major Research Activities

The intestinal microbiome senses and reacts to our environment. Dysbiosis is an altered microbiome with reduced bacteria diversity, increased mucosal barrier permeability and aberrant local immune responses. Men and women are often malnourished before cardiac surgery and are at high risk for intestinal dysbiosis given dietary insufficiency and antibiotic use. Using a mouse model of a major cardiac surgery we are testing the hypothesis that surgery induces a sex-dependent gut dysbiosis that hampers healing.

We have 3 aims:

  • First, we will define the physiological, immune, microbiota and metabolome responses post-cardiac surgery. Our goal is to characterize surgery-induced gut dysbiosis, cardiac structure/function, and inflammatory cell infiltration into the heart and to assess the potential for gut-specific changes to negatively affect cardiac repair and function post-surgery in mice and then humans.
  • Secondly, we plan to re-engineer the mouse gut microbiome by transplant of mouse or human fecal matter. We will test the impact of antibiotics usually prescribed on the gut microbiota composition. Here, we will test if the addition of beneficial bacteria will alleviate gut dysbiosis and if antibiotics hinder or help recovery.
  • Thirdly, we are investigating the role of diet and diet supplementation during the immediate post-surgery period on recovery. We test a resistant starch enriched diet which is designed to increase beneficial bacteria on recovery. Mimicking a Western diet typical of the malnourished elderly, we will test if a poor diet impairs recovery equally in male and female mice and if supplementation of microbiota-sparing nutrients will allow a better recovery.

Recent Publications and References