Abstract

Antagonistic coevolution (AC) is defined as the reciprocal selection for host resistance and parasite infectivity. Bacteria and their lytic viral parasites, bacteriophages or phages, are ubiquitous and highly abundant components of the biosphere and AC between bacteria and phages is now recognised to play a key role in driving and maintaining microbial diversity. Consequently, AC is predicted to affect all levels of biological organisation, from the individual to ecosystem scales. Nonetheless, we know very little about bacteria–phage AC in perhaps the most important and clinically relevant microbial ecosystem known to mankind – the human gut microbiome. In this seminar I will present data emerging from the temporal analysis of populations of bacteria and phages isolated from the human gut as well as results from a complementary in vitro study that was developed to study AC dynamics between populations of gut bacteria and associated phages. Finally, I will discuss these data in the context of AC and its potential role in driving observed patterns of intra- and interindividual variation in the gut microbiome together with detailing the functional consequences of such AC-driven microbial variation for human health and disease.