The Glycine Lipids of Bacteroides thetaiotaomicron Are Important for Fitness during Growth In Vivo and In Vitro

The gut microbiome has an important role in both health and disease of the host. The mammalian gut microbiome is often dominated by bacteria from the Bacteroidales , an order that includes Bacteroides and Prevotella . In this study, we have identified an acylated amino acid, called glycine lipid, produced by Bacteroides thetaiotaomicron , a beneficial bacterium originally isolated from the human gut. In addition to identifying the genes required for the production of glycine lipids, we show that glycine lipids have an important role during the adaptation of B. thetaiotaomicron to a number of environmental stresses, including exposure to either bile or air. We also show that glycine lipids are important for the normal colonization of the murine gut by B. thetaiotaomicron . This work identifies glycine lipids as an important fitness determinant in B. thetaiotaomicron and therefore increases our understanding of the molecular mechanisms underpinning colonization of the mammalian gut by beneficial bacteria.