Why study gut microbes? This is a question I am constantly addressed with while trying to explain my research interests. My response? Why not study gut microbes?! The microbiome of living organisms has been termed the “forgotten organ”, with a collective metabolic activity equal to that of a virtual organ. Gut microbes in particular are of crucial importance to their host, assisting in digestion of food matter, absorption of nutrients and development of a properly functioning immune system. Studies estimate that the number of genes within the gastrointestinal microbiome is 100 times greater than that of the human genome. So, it comes as no surprise that scientists across multiple fields have been diving head first into the world of gut microbes, in hopes of better understanding everything from individual organisms to entire population structures.
My research focuses on immunomodulating gut bacteria, or groups of bacteria in the vertebrate gut that affect host immune homeostasis. In particular, I am interested in a group of bacteria called segmented filamentous bacteria (SFB). These tiny inhabitants of the intestines have amazing capabilities to directly influence the production of T helper cells that produce inflammatory cytokines in the body. This is paramount in protecting the body from disease and infection.
But how does this relate back to conservation biology? In order to effectively protect species, we must understand them at all levels, including the inner antics of their tiny commensal friends. These bacteria are heavily influenced by diet and environment, so it is assumed that in a changing world, the composition of the gut microbiota will change as well, ultimately affecting host health. Studying immunomodulating bacteria and what affects them, could give conservation biologists a more solid base for understanding the health status of species in a rapidly changing world. With the importance of gut microbes growing with every newly published study, it is clear that we must put increased focus on studying them through the lens of ecology and conservation.
Right now, I have two projects to investigate this unbelievably interesting stuff! Dr. Pat Thomas (Vice President at the Bronx Zoo) and I have captured and transitioned wild house mice into captivity at the Bronx Zoo. Some of these mice are being fed a standard zoo diet, while others are being fed a diet more similar to what a house mouse would eat in the wild, varied by season. The plan is for these mice to reproduce to produce multiple generations, mimicking the process that happens every day in captive facilities. We will test for levels of SFB between the two diet treatments and over multiple generations. The goal will be to investigate the effects of a captive diet on levels of SFB. This information can hopefully provide zoos, (which are an increasingly important tool in the conservation toolkit) with information to better the health of their captive populations for future reintroductions. The second project focuses on mice in the wild. I will be trapping wild white-footed mice from urban, suburban and rural field sites. Levels of SFB will be compared between these populations to shed some light on how urbanization affects levels of SFB in wild populations of organisms. These results could provide conservation biologists with information on how increased urbanization in the coming years may affect the health of species in the wild.
The bottom line is that there is much work to be done. There are hundreds of distinct species present in the mammalian gastrointestinal tract with many specific functions crucial to their host. Studying them could give us an astronomically enhanced understanding of how organisms function, and even how populations of organisms function. So, in closing, that is why I study gut microbes! More to come from the field in the coming weeks!