Worms, bugs and drugs: Caenorhabditis elegans as a model for host-microbe-drug interactions

The microbiota plays a critical role in human health and disease. For instance, the gut microbiota aides in the digestion of foods, thereby contributing to our ability to metabolize compounds from our diet. Recently, it has become clear that the microbiota can also play an important role in the response to medications. However, several limitations in utilizing mammalian model systems, such as complex microbiota, high cost, and limited scalability, have constrained our ability to systematically test which bacteria affect the drug response and the mechanisms involved. The nematode Caenorhabditis elegans and its bacterial diet provide a facile interspecies model system to identify and characterize host-microbe-drug interactions. Two recent studies highlight the power of this model system. In brief, these studies identified two roles for bacteria in modulating the host drug response: (1) metabolic drug activation, and (2) supplementation of vitamins or nucleotides that affect the host's drug response. This review will summarize the main findings of both studies, as well as provide some perspective into the advantages and limitations of the C. elegans-bacteria model for the detailed characterization of host-microbiota-drug interactions.