Grant: Project Grant

The trillions of bacteria that live in the human body, known as the microbiome, are increasingly recognized as key players in cancer. While most studies have focused on the gut, recent discoveries show that bacteria are also present in the lungs and even inside tumors themselves. These microbes may directly shape how cancers develop, progress, and respond to treatment. During my fellowship, I showed that bacteria within lung tumors are linked to a more inflamed tumor environment and improved survival in patients treated with immunotherapy. However, it remains unknown whether bacteria found in the lungs can colonize tumors, remain alive inside them, and influence lung cancer biology. Our research will address this gap by focusing on lung cancer, the leading cause of cancer deaths in Canada. Using bronchoalveolar lavage (BAL)-a routine clinical procedure-we will profile the lung microbiome in patients with and without lung cancer. We will combine state-of-the-art sequencing with culturomics, a high-throughput culture method that uniquely demonstrates whether bacteria are alive. We will then analyze paired BAL and tumor samples from large biobanks to determine whether airway bacteria seed tumors and how microbes interact with cancer and immune cells. Finally, we will use mouse models to test whether introducing specific bacteria into tumors alters cancer growth and the tumor microenvironment. By moving beyond descriptive studies to prove whether lung and tumor bacteria are viable and functional, our work will provide new biological insight into how cancers evolve. This research could lead to new microbiome-based screening tools to detect lung cancer earlier and innovative therapies that target harmful bacteria to improve patient outcomes.