Longitudinal profiles of the vaginal microbiota of pre-, peri-, and postmenopausal women: preliminary insights from a secondary data analysis

Abstract Objective Menopause is often accompanied by lowered Lactobacillus spp. relative abundance and increased abundance of diverse anaerobic/aerobic bacteria in the vaginal microbiota due in part to declines in estrogen. These microbiota are associated with urogenital symptoms and infections. In premenopause, vaginal microbiota can fluctuate rapidly, particularly with menstrual cycles and sexual activity; however, the longitudinal dynamics of vaginal microbiota are understudied in peri- and postmenopause. We described vaginal community stability across reproductive stages. Methods Pre- (n = 83), peri- (n = 8), and postmenopausal (n = 11) participants provided twice-weekly mid-vaginal samples (total, 1,556; average, 15 per participant) over 8 weeks in an observational study. Composition of the vaginal microbiota was characterized by 16S rRNA gene amplicon sequencing, and a community state type (CST) was assigned to each sample. Clustering of longitudinal CST profiles, CST transition rates, duration of low- Lactobacillus /high bacterial diversity CSTs, and other metrics of bacterial community dynamics were assessed across reproductive stages. Results The proportion of participants with longitudinal CST profiles characterized by low- Lactobacillus CSTs was similar among pre- (38.6%), peri- (37.5%), and postmenopausal (36.4%) participants ( P = 0.69). CST transition rates between consecutive samples were 21.1%, 16.7%, and 14.6% for pre-, peri-, and postmenopausal participants, respectively ( P = 0.49). Low- Lactobacillus CST tended to persist for at least 4 weeks, irrespective of reproductive stage. Conclusions Findings from this small yet frequently sampled cohort revealed vaginal bacterial fluctuations over 8 weeks that were similar across reproductive stages. Larger and longer-term studies based on these preliminary data could provide insights into the influence of microbiota dynamics on urogenital outcomes during menopause.