TOXIC METAL EXPOSURE IN CATTLE AND DISCOVERY OF MICROBIOME FUNCTIONS THAT MITIGATE INPUT INTO THE FOOD CHAIN

The first objective of this project is to conduct experimental exposures in cattle to the top four metal toxicants threatening human health. In mammals, the gut microbiome helps detoxify metals, suggesting microbiome-focused therapies could mitigate spillover into the food chain. The second objective of this project is to identify the most efficient, potentially novel, metal detoxifying mechanisms among bovine gut microbes. We propose to evaluate the gut microbiome of bison (Bison bison) that overwinter in geothermal areas with high levels of toxic metals in Yellowstone National Park. An observational study is proposed to collect samples (feces and urine) from overwintering bison, identify metal tolerant/resistant microorganisms and statistically correlate their abundance with metal content in urine. Validation of metal detoxification activities will be performed by cloning enriched loci and performing in vitro bioassays. Stakeholders in the bison industry helped guide development of this project and are now collaboratively providing expertise and sampling opportunities. Results from this work will lead to improved risk assessment and provide key information for metal mitigation strategies by the gut microbiome.