All natural populations are constantly subject to new mutations, and frequently face novel environments, to which they adapt. However fundamental questions such as: What is the rate and distribution of fitness effects of mutations across environments? What fraction of the genome is under positive selection? How does natural selection operates in the context of a complex ecosystem? Still remain incompletely answered.

Our lab is performing research to answer these fundamental questions,  by studying bacteria that colonise the mammalian gut.

We use Escherichia coli and Mus musculus as our main model study systems. E. coli is a typical coloniser of the gut of most humans and of many mammals. Laboratory mice offer the power of mouse genetics to gain deeper insights on the mechanisms underlying host-microbe interactions. 

We combine empirical work with theoretical modelling with the aim at a better understanding of the major forces that shape variation in microbial populations colonising healthy and ailing hosts.