Neutral mutants can prevail in gut microbiota, enhancing diversity

Scientists at EPFL and Sorbonne propose a new model of the diversity and evolution of gut bacteria that shows how the gut environment helps neutral mutations become prevalent, with significant potential implications on health and metabolic diseases. We are used to thinking of evolution as a very slow process, and this is definitely the case for large mammals etc,- says Professor Anne-Florence Bitbol at EPFL's School of Life Sciences. -But viruses evolve quite fast, as the quick succession of COVID-19 variants shows us. Bacteria evolve at intermediate timescales, and those present in our gut can evolve at timescales relevant for us. The mutation and evolution of gut bacteria, can affect public health in a significant way; an obvious example is antibiotic resistance. Consequently, much research has gone into working out the factors that influence the evolution of gut bacteria, and some studies have pointed to the actual structure of the gut, including its hydrodynamic flow that causes different gradients of food and bacterial concentrations across its length. A new model of the gut Working with Darka Labavic and Claude Loverdo of Sorbonne University, Bitbol has now developed a -minimal model- of bacterial mutation and evolution in the gut, providing some keen insights about how the guts internal flow affect the distribution of the gene pool.