HIV-exposed seronegative individuals (HESIs) are a small fraction of persons who are multiply exposed to human immunodeficiency virus (HIV), but do not exhibit serological or clinical evidence of HIV infection. In other words, they are groups of people maintaining an uninfected status for a long time, even after being exposed to HIV several times. The long-term non-progressors (LTNPs), on the other hand, are a group of HIV-infected individuals (approx. 5%) who remain clinically and immunologically stable for an extended number of years without combination antiretroviral therapy (cART). Meanwhile, elite controllers are comprise a much lower number (0.5%) of HIV-infected persons who spontaneously and durably control viremia to below levels of detection for at least 12 months, even when using the most sensitive assays, such as polymerase chain reaction (PCR) in the absence of cART. Despite the fact that there is no universal agreement regarding the mechanisms by which these groups of individuals are able to control HIV infection and/or disease progression, there is a general consensus that the mechanisms of protection are multifaceted and include genetic, immunological as well as viral factors. In this review, we analyze and compare the biological factors responsible for the control of HIV in these unique groups of individuals.

As a rapidly growing field of research over the past two decades, the Gut Microbiome has emerged as an important player with an integral role in human body functions. Its perturbed function correlates with several diseases such as diabetes, obesity, liver dysfunction, degenerative conditions, and neurological conditions. Studies utilizing the technological advancements with multi-omics methodologies continue to allow the detection and identification of gut microbes and provide mechanistic insights into their functioning. This review provides an overall understanding of the gut microbiome, its function, and communication with the brain and liver via the gut-brain axis and gut-liver axis. This review further discusses its role in some of the common disease states and some ways to potentially modulate the gut microbiome.