Gastrointestinal (GI) immune system competency is dependent upon interactions with commensal microbiota, which can be influenced by wide-ranging pharmacologic interventions. In simian immunodeficiency virus (SIV)-infected Asian macaque models of human immunodeficiency virus (HIV) infection, we previously noted that initiation of antiretroviral therapy (ART) is associated with a specific imbalance (dysbiosis) of the composition of the intestinal bacteriome. To determine if ART itself might contribute to dysbiosis or immune dysfunction, we treated healthy rhesus macaques with protease, integrase, or reverse transcriptase inhibitors for 1 to 2 or for 5 to 6 weeks and evaluated intestinal immune function and the composition of the fecal bacterial microbiome. We observed that individual antiretrovirals (ARVs) modestly altered intestinal T-cell proinflammatory responses without disturbing total or activated T-cell frequencies. Moreover, we observed transient disruptions in bacterial diversity coupled with perturbations in the relative frequencies of bacterial communities. Shifts in specific bacterial frequencies were not persistent posttreatment, however, with individual taxa showing only isolated associations with T-cell proinflammatory responses. Our findings suggest that intestinal bacterial instability and modest immunological alterations can result from ART itself. These data could lead to therapeutic interventions which stabilize the microbiome in individuals prescribed ART. [ABSTRACT FROM AUTHOR]