Long-term low-dose administration of THC to simian immunodeficiency virus infected rhesus macaques suppressed neuroinflammation and dysbiosis. Specifically, THC administration increased the abundance of beneficial bacteria like Clostridia including bacterial species the produced indole-3-propionate and short chain fattyacids (butyrate) and reduced the abundance of the pathogenic bacteria. Overall, these findings suggest that THC could help reduce neuro and systemic inflammation in human immunodeficiency virus infected individuals.