Grant: Doctoral: Vanier Canada Graduate Scholarships

The microbiome consists of trillions of bacteria, viruses and fungi that co-exist with humans in sites such as the intestines, nose and mouth, and is important to most aspects of health. My project will explore links between the microbiome and Parkinson's (PD) and Alzheimer's disease (AD) and the conditions that often accompany these diseases, such as depression and anxiety. PD leads to loss of motor control and affects 100,000 Canadians. Studies have shown that the intestinal microbiome differs between those with and without PD. Interestingly, most patients experience constipation and loss of smell years before motor symptoms; these early symptoms take place at sites densely populated by microbes. AD is the leading cause of dementia, which affects 400,000 Canadians. Animal studies have found that the microbiome is important in AD; therefore, this is a key area to explore in humans. My first aim is to compare the microbiome of PD and AD patients versus controls. We will see whether a microbial "signature" exists for each disease and associate microbiome findings with disease severity. A second aim is to see whether probiotics improve depression, anxiety and fatigue in PD, as these conditions are also associated with microbial imbalances. As most patients have intestinal problems, we hope that shifting their microbiome to a healthier state could improve these symptoms. Finally, any discoveries will be further explored in the lab to understand the mechanisms connecting microbes to brain diseases. This will include seeing whether different microbial populations can modify PD/AD symptoms in mice, and examining how molecules made by microbes impact cells such as neurons and immune cells. The goal of my research is to provide new understanding of how the microbiome is important in neurodegenerative disease, and ultimately to work towards non-invasive interventions such as diet changes or carefully-designed probiotics that might help treat or even prevent these diseases.