Spatiotemporal population dynamics of native and engineered bacteria in the gut microbiome

Colorectal (CRC) cancer is the fourth most commonly diagnosed cancer and the fourth most common cause of cancer deaths in the US. Recent studies have indicated a rise in CRC in adults under fifty, a subset of the population that does not undergo regular screening for CRC. Recent research shows that the gut microbiome plays an important role in CRC. We are part of a collaborative team of experimentalists and modelers developing a non-invasive approach where genetically modified native bacteria in the gut microbiome can be used to diagnose and disrupt CRC. As part of the theory and modeling, we use a generalized model of population dynamics that extends the Lotka-Volterra equations beyond the usual predator-prey dynamics to include other types of interactions between engineered and native bacterial species. We also include bacteria's diffusion and advection to account for the spatial movement and variation of different bacterial populations. By solving the resulting spatiotemporal population dynamics, we make predictions of the conditions for the survival and grafting of engineered bacterial populations in the gut microbiome. Our results also provide an understanding of how different types of microbial interactions impact the dynamics of these bacterial populations.