The overarching theme for this program project grant (PPG) is that alcohol associated gut dysbiosis and gut dysbiotic metabolites are cardiovascular disease (CVD) risk factors among people living with HIV infection (PLWH) who are heavy drinkers. The goals of this research are (1) to determine if a tailored probiotic (i.e., contains bacteria supporting butyrate synthesis) can mitigate alcohol associated gut dysbiosis and lower levels of microbial translocation, inflammation, and improve harmful dysbiotic metabolite profiles (e.g. trimethylamine N oxide, TMAO) and (2) to determine if these metabolites are associated with incident CVD and death among PLWH. We hypothesize that, among PLWH, a probiotic vs. placebo can mitigate alcohol associated gut dysbiosis and lower levels of microbial translocation, inflammation, and improve metabolite profiles (Project 1 RCT, n=250); and that harmful alterations of these metabolites will be associated with higher risk of incident CVD and death (Project 2 Cohort, n=2,900). Project 1 will be conducted at Pavlov State Medical University in St. Petersburg, Russia, the same site as our gut microbiome and metabolite studies (ACME HIV and TMAO HIV). Project 2 will leverage the Veterans Aging Cohort Study, an observational cohort of veterans living with and without HIV. The Projects will be supported by our Administrative Core at Vanderbilt University Medical Center and the Integrated Metagenomics and Metabolomics Core at the University of Louisville's Alcohol Research Center (ULARC). The latter is the core for ACME HIV and will generate the metagenomics and metabolomics for this PPG. The former will coordinate all study projects/cores and integrate the Vanderbilt SCHolars in HIV and Heart, Lung, Blood, and Sleep ReSearch NIH K12 training program into the PPG. Our preliminary data: (1) HIV infection is a CVD risk factor; (2) inflammation is associated with increased risk of CVD among PLWH; (3) among PLWH, heavy drinking is associated with increased CVD risk and correlated with measures of gut dysbiosis, characterized by loss of butyrate producing bacteria; (4) gut dysbiosis among PLWH who are heavy drinkers is correlated with higher levels of inflammation, TMAO, and adverse bile acid metabolite profiles; and (5) ULARC data in murine models show heavy drinking causes dysbiosis, that dysbiosis leads to increased biomarker levels of inflammation, and that probiotic administration targeting alcohol-associated gut dysbiosis attenuates the rise in these inflammatory biomarkers even in the presence of alcohol consumption. Cross project validation: Biospecimens from Project 1 will be used to validate significant findings in Project 2. Metabolites significantly associated with alcohol and CVD in Project 2, will be explored in Project 1 to see if probiotics favorably impact the levels of those metabolites. The Microbiome, METabolites, and Alcohol in HIV to reduce CVD (META HIV CVD) PPG will inform probiotics' role as standard adju...