It has become increasingly apparent how important the microbiome is to a host’s fitness, including our own. However, relatively little is known about the molecular mechanisms employed by symbiotic bacteria to stably colonize the gut, as they are difficult to experimentally study in isolation. As an NIH Early Independence Award recipient, I am developing the Siphamia–Photobacterium symbiosis as an experimentally tractable vertebrate model to help disentangle the complex mechanisms that shape and regulate specific microbe-host associations. This binary, gut-associated symbiosis has unlimited potential to advance our understanding of the symbiotic interactions with beneficial bacteria on which we depend.