Intestinal microbiota facilitates food breakdown for energy metabolism and influences the im-mune response and maintaining mucosal homeostasis. Overall, HIV infection is associated with intestinal dysbiosis and immune activation, which has been related to seroconversion in HIV-exposed individuals. However, to date, it is unclear whether microbiota dysbiosis is the cause or the effect of immune alterations and disease progression. We characterize the intestinal microbiota and determine its association with immune regulation in HIV-exposed seronegative individuals (HESN), HIV-infected progressors (HIV+), and healthy control (HC) subjects. For this, feces and blood were collected. The microbiota composition of HESN showed a significantly higher alpha and beta diversity compared to HC, but similar to HIV+. A lower Treg percentage was observed in HESN than HC and HIV+, with enrichment of the genus Butyrivibrio being characteristic of this profile. Interestingly, an increase in Succinivibrio and Prevotella and a re-duction in Bacteroides genus were observed in HESN compared to HC, which is typical of HIV-infected individuals. Thus, HESNs have a microbiota profile, similar to that observed in HIV+, most likely because HESN are cohabiting with their HIV+ partners.Intestinal microbiota facilitates food breakdown for energy metabolism and influences the im-mune response and maintaining mucosal homeostasis. Overall, HIV infection is associated with intestinal dysbiosis and immune activation, which has been related to seroconversion in HIV-exposed individuals. However, to date, it is unclear whether microbiota dysbiosis is the cause or the effect of immune alterations and disease progression. We characterize the intestinal microbiota and determine its association with immune regulation in HIV-exposed seronegative individuals (HESN), HIV-infected progressors (HIV+), and healthy control (HC) subjects. For this, feces and blood were collected. The microbiota composition of HESN showed a significantly higher alpha and beta diversity compared to HC, but similar to HIV+. A lower Treg percentage was observed in HESN than HC and HIV+, with enrichment of the genus Butyrivibrio being characteristic of this profile. Interestingly, an increase in Succinivibrio and Prevotella and a re-duction in Bacteroides genus were observed in HESN compared to HC, which is typical of HIV-infected individuals. Thus, HESNs have a microbiota profile, similar to that observed in HIV+, most likely because HESN are cohabiting with their HIV+ partners.https://scienti.minciencias.gov.co/cvlac/EnProdArticulo/query.do?cod_producto=73&cod_rh=0000157775https://scholar.google.com.co/citations?hl=en&user=VLZxl1UAAAAJCOL0112548https://orcid.org/0000-0002-7351-873
