S-Equol: a novel therapeutic for HIV-1-associated gastrointestinal dysbiosis.

Objective: HIV-1 infection affects approximately 38.4 million people around the world. The advent of combination anti-retroviral therapy (cART) has greatly improved the quality of life of infected individuals; however, roughly 50 % of these individuals will still experience HIV-1-associated neurocognitive disorders (HAND). Additionally, the gastrointestinal microbiome has been reported to be dysbiotic in HIV-1 infected individuals, regardless of adherence to cART. Current research has pointed to the gut-brain-microbiota axis as a potential target to treat both cognitive deficits and microbial changes. The present study investigated S-Equol (SE) as a potential therapeutic for HAND by modulating the gastrointestinal microbiome. Methods: The study included 21 HIV-1 Tg rats and 21 F344 control animals to test the effect 0.2 mg SE has on cocaine-maintained responding on a PR schedule of reinforcement. Results: Gastrointestinal microbiome alterations between genotypes were found at the phylum and genus level, regardless of treatment group, and SE treatment had both main effects and interactions with genotype. Prevotella_UCG_001 was significantly associated with lever presses for drug, suggesting an effect on motivation for cocaine. Alloprevotella was found to significantly differentiate between genotype by treatment effects, indicating that SE differently affects genotypes. Conclusions: SE may provide a novel adjuvant treatment in addition to cART for HIV-1-associated dysbiosis and associated neurocognitive dysfunction.