Consistent with an important role for adaptive immunity in modulating interactions between intestinal bacteria and host, dramatic alteration in the composition of gut microbes during chronic HIV infection was recently reported by ourselves and independently by four other research groups. Here we evaluate our results in the context of these other studies and delve into the effects of antiretroviral therapy (ART). Although gut microbiota of HIV-positive individuals on ART usually does not resemble that of HIV-negative individuals, the degree to which ART restores health-associated prevalence varies across bacterial taxa. Finally, we discuss potential drivers and health consequences of gut microbiota alterations. We propose that understanding the mechanism of HIV-associated gut microbiota changes will elucidate the role of adaptive immunity in shaping gut microbiota composition, and lay the foundation for therapeutics targeting the microbiota to attenuate HIV disease progression and reduce the risk of gut-linked disease in people with HIV.
Keywords: CD4+ T cells; bacteria; bacteroides; gastrointestinal tract; inflammation; metabolic disease; microbiome; prevotella; regulatory T cells.