BRC-BIO: Evolution of nitrogen exchange and transformation in mammalian gut microbes

About This Grant

All mammals house a community of microbes in their digestive tracts. These microbes influence their hosts by consuming and transforming nutrients from the host itself and the host’s diet. Many of these microbes are found in a relatively small number of host species, suggesting that they may be adapted to the specific nutrient environment of their particular host. These adaptations could lead to differences in the overall function of the gut microbiome across host species. Improved understanding of variation in gut microbiome composition and function could have important implications for the use of probiotics to improve human health or livestock production. This project will study how gut microbes from different host species vary in their capacities to use and transform nitrogen, an essential nutrient that impacts the growth and activity of many gut microbes. Undergraduate students will contribute to data collection and analysis as research assistants and in a new course-based research experience in microbiology. As part of this project, researchers will create and share reusable materials for advanced education and training in microbial genomics. This project will investigate the role of nitrogen source availability as a determinant of host range in mammalian gut microbes. Nitrogen is thought to be biomass-limiting in the gut of many hosts, yet how nitrogen availability may shape microbiome metabolism and adaptation is largely unknown. First, researchers will computationally reconstruct the microbial network of nitrogen-transforming metabolic reactions in various mammalian hosts using a set of metabolic annotation tools applied to public metagenomic datasets. This resource will be used to assess evidence for diversification and dietary specialization of nitrogen pathways in microbial taxonomic groups that are broadly found across mammalian hosts. Secondly, researchers will study the adaptive responses of representatives of two model bacterial species from different mammalian hosts to varying nitrogen source conditions in experimental settings. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.