Given the highly complex nature of HIV, including the challenges of protecting mucosal surfaces from transmission and high variability of the virus, developing innovative vaccination strategies is crucial. Indeed, despite extensive research, a fully efficacious vaccine to prevent HIV transmission remains elusive, and there is limited understanding of correlates of protection, particularly at mucosal surfaces. Recently, the importance of the microbiome in mucosal immunity have become appreciated, and here we hypothesize that we can exploit the microbiome to induce protective vaccine responses. Here we propose a novel HIV vaccination approach that uses persistent probiotic therapy as an adjuvant to enhance immunogenicity and protection induced by a potent combined vaccine strategy. Our vaccine consists of concurrently administered SIV (gag p55) and HIV (gp140) DNA + HIV gp140 trimer protein. Recent studies have provided evidence that combining DNA and protein for vaccination elicits increased vaccine specific cellular and humoral immunity, In addition, our preliminary studies provocatively demonstrated that probiotic treatment in SIV-uninfected macaques results in increased T follicular helper cells in lymph nodes, IgA expressing B cells in mucosal tissues, increased antigen presenting cells in mucosal tissues, and increased multifunctional T cells, as well as decreased proliferation and activation of CD4+ T cells. Thus, we hypothesize that combining the potent immunomodulatory effects of beneficial microbiota manipulation with a novel vaccine platform that should induce robust cellular and humoral immunity will result in unprecedented high levels of vaccine specific responses in both mucosal and systemic tissues, resulting in protection from rectal SHIV challenge. There are several innovative aspects of this vaccine design, including: (i.) Modulation of the microbiota with probiotics to enhance mucosal vaccine responses; (ii.) utilization of a novel dual SHIV DNA-HIV gp140 protein vaccination platform; (iii.) novel measurements of potential vaccination correlates will be measured including microbiome morphogenesis, homeostatic mucosal responses, innate immune responses, and T follicular helper and germinal center B cell responses, in addition to standard correlates of vaccination (antibody and T cell responses).