To address these questions, healthy women of reproductive age will receive a 10-day course of amoxicillin (a broad-spectrum, beta-lactam antibiotic) or a placeboand will undergo vaginal sampling for microbiomic and immunologic analyses before, during and after antibiotic administration over a 90-day period. The hypothesis of this study is that women who develop amoxicillin-associated VVC will have a characteristic microbiomic profile (as compared to women with absent or asymptomatic Candida colonization) with associated impairment in local mucosal anti-Candida immune responses. The aim of this study is to elucidate the vaginal microbiomic and immunologic perturbations that allow Candida to transition from commensal to pathogen in the context of antibiotic administration. A better understanding of the role of specific microbiota and mucosal immune factors in averting Candida infection may lead to the design of targeted preventive and/or therapeutic interventions against VVC.