This project aims to explore impact of acute mTBI on the human microbiome and the effects of the human microbiome on mental health outcomes post-injury. Since the start of this longitudinal study, regulatory approval has been obtained and study personnel were hired and trained. Nine participants have been recruited. Initial samples at baseline were obtained and ongoing data collection has been initiated. During the pause of recruitment due to COVID-19, follow-up data collection has continued for those previously enrolled in the study.