Beating cancer by eating cancer

Researchers engineer bacteria capable of consuming tumours from the inside out

At first glance, infecting yourself with bacteria to get healthy sounds counterintuitive. How could something that gets us sick make us better? But bacteria, like people, come in many varieties: some are beneficial which we consider symbiotic and some are harmful which we consider pathogenic; but the vast majority are neutral and don’t have a direct impact on our day-to-day lives. Dr. Marc Aucoin and his research group at the University of Waterloo are exploiting this dynamic by genetically engineering bacteria to destroy cancer tumors.

             This study utilizes Clostridium sporogeneses, an anaerobic bacterium often found in soil. Anaerobic bacteria thrive in oxygen-poor environments such as deep soil, lake mud, and even within the guts of animals and humans. As tumors grow, oxygen struggles to reach the center of the tumor, leaving it starved of oxygen or “hypoxic”. The human cells in these hypoxic regions can’t survive and die off leading to a buildup of cellular debris, creating a hypoxic environment full of nutrients, the perfect spot for anaerobic bacteria to thrive.

             Capitalizing on this realization, Dr. Marc Aucoins’ research group started by introducing their genetically engineered spores to the tumor region. There, the spores would seek out the perfect place to colonize and grow, which happens to be the hypoxic regions at the center of cancer tumors. Once the hypoxic area of the tumor is destroyed, the anaerobic bacteria are no longer able to thrive as outside of the hypoxic area; as healthy tissue is  oxygen-rich and inhospitable to them. While this is an amazing find, this study also highlights the importance of intersectionality in science, as without collaboration between microbiologists, engineers, and cancer biologists this groundbreaking discovery would never have been found.