Microbial translocation in HIV infection: causes, consequences and treatment opportunities

Even when receiving antiretroviral therapy, HIV-infected individuals have an increased risk of mortality owing to systemic immune activation. Sandler and Douek review evidence showing that the translocation of microbial products from the intestine into the circulation may contribute to this risk and discuss potential therapeutic strategies. Systemic immune activation is increased in HIV-infected individuals, even in the setting of virus suppression with antiretroviral therapy. Although numerous factors may contribute, microbial products have recently emerged as potential drivers of this immune activation. In this Review, we describe the intestinal damage that occurs in HIV infection, the evidence for translocation of microbial products into the systemic circulation and the pathways by which these products activate the immune system. We also discuss novel therapies that disrupt the translocation of microbial products and the downstream effects of microbial translocation.