Vaginal microbiota and genitourinary menopausal symptoms

The overall objective of the project was to examine associations between the composition of the vaginal microbiota and genitourinary menopausal symptoms, serum estrogen, and vaginal glycogen. Women (n=88) ages 40-62 enrolled in a hot flash treatment trial provided vaginal swabs and a blood sample at enrollment. Women with symptoms (n=38) contributed samples at weeks 4 and 8 after intervention with either venlafaxine (n=10), estradiol (n=9) or placebo (n=19). Bacterial communities were characterized using 16S rRNA PCR and deep sequencing targeting the V3-V4 region. Self-reported genitourinary symptoms included: 1) presence and severity of individual symptoms and 2) identification of most bothersome symptom. Glycogen was measured fluorometrically in swab eluate. Serum estradiol (E2) and estrone (E1) were measured by liquid chromatography/mass spectrometry. Associations between bacteria, symptoms, glycogen, and serum estrogens were tested by linear regression or Wilcoxon signed-rank test, adjusted for multiple comparisons. Comparisons between groups used Kruskall-Wallis or Fisher's exact test. Of the 88 women, 33 (38%) had a majority of Lactobacillus species, while 58 (66%) had any Lactobacillus detected. Over half (53%) reported ≥ 1 vulvovaginal symptom (most commonly dryness. Women with Lactobacillus dominant communities had higher unconjugated serum estrone, but no difference in vaginal glycogen levels, compared to those with non-Lactobacillus dominant communities. Higher serum E2 and E1 were not associated with higher vaginal glycogen, nor detection of individual genera. Presence of Lactobacillus-dominant vaginal microbiota was not associated with vulvovaginal symptoms. Serum estrone was higher in women with Lactobacillus-dominance, but vaginal free glycogen was not associated with composition of the vaginal microbiota.