Estrogen, Probiotics and Vaginal Health to Prevent HIV Infection in ACB Women

Women are at increased risk of HIV acquisition compared with men. A number of biological factors are associated with increased risk, many of which likely enhance risk by increasing inflammation in the female genital tract. Susceptibility to infections and immune responses in the female genital tract are regulated by hormones: progesterone increases inflammation and HIV susceptibility and estrogen decreases inflammation and enhances colonization with Lactobacilli. A Lactobacillus dominant vaginal microbiome is associated with increased protection against HIV, while a polymicrobial vaginal flora, as seen in bacterial vaginosis, is associated with increased risk. About 40% of ACB women have a polymicrobial flora. The goal of this study is to establish a Lactobacillus dominant vaginal microbiome in ACB women, that will be associated with decreased inflammation and decreased susceptibility to HIV, by administering a low level of intravaginal estrogen to increase colonization with Lactobacilli together with a Lactobacillus‐containing probiotic.