Association of Amino Acid Prevalence and Chronic Brain Injury

Years after a suffering a brain injury, individuals remain in a physically and cognitively impaired state. The investigators believe that the concentrations of amino acids in the blood are chronically altered and yield negative effects on the individuals health. Preliminary data has shown significantly lower concentrations of amino acids in serum samples from the TBI population, these diminished levels of amino acids may be due to changes in the microbiome. Understanding these changes will help guide rehabilitative services for this population. Individuals with a chronic brain injury will donate samples of blood, oral tissue, and fecal matter to be compared to that of non-injured individuals. Genetic information from the hosts will be striped and discarded; participant\'s genetic information will not be retained. To better understand changes in the microbiome, any history of antibiotics and probiotics will be assessed.