Research

Our intestines are home to a complex community of trillions of microbes collectively known as the gut microbiota. Studies using germ-free and gnotobiotic mice have demonstrated that the gut microbiota critically impacts numerous aspects of host development and physiology and host susceptibility to infection and chronic disease. The gut microbiota is directly exposed to our diet, xenobiotics and endogenous hormones and chemicals synthesized by our bodies. Therefore, our overarching research goal is to investigate how diet- and host-derived signals modulate the behaviors and physiology of the gut microbiota and consequent host-bacterial interactions.  

We are broadly interested in studying how gut resident bacteria and invading pathogens sense specific nutrients and signaling molecules and how these molecular interactions a) shape bacterial physiology and behaviors in the gut, and b) modulate host-bacterial interactions and host susceptibility to infection and chronic inflammatory diseases. In particular, we are investigating how dietary lipids and endocannabinoids, a class of lipid hormones synthesized by the host, modulate the behaviors of commensal and pathogenic E. coli in the gut. Endocannabinoids regulate various aspects of mammalian biology, including intestinal physiology and immunity, through their engagement with cannabinoid receptors expressed on host cells. Recently, my postdoctoral work demonstrated that one specific endocannabinoid, 2-arachidonoyl glycerol, is also recognized by a provirulence receptor that is expressed by numerous important Enterobacteriaceae including E. coli and Salmonella. This interaction attenuates the virulence of several enteric pathogens, thus providing a direct molecular mechanism by which the mammalian endocannabinoid system can modulate the outcome of infection. Using a combination of microbial genetics, in vitro infections and mouse models, we are interested in investigating whether other endocannabinoids and dietary lipids are also sensed by gut bacteria and the consequent effects on bacterial function, host-bacterial interactions and disease susceptibility in the host.