Exploratory comparison of vaginal glycogen and Lactobacillus levels in premenopausal and postmenopausal women

Abstract

Objective Previous studies have suggested that glycogen expression in vaginal epithelium decreases at menopause, resulting in reduced levels of lactobacilli. However, free glycogen in genital fluids and its relationship to Lactobacillus levels has not been compared in pre- and post-menopausal women. Methods 82 cervico-vaginal lavage samples were collected at different phases of the menstrual cycle from 11 pre-menopausal (4 HIV-uninfected and 7 HIV-infected) and 12 post-menopausal (7 HIV-uninfected and 5 HIV-infected) women over a 1–3 month period. Free glycogen was quantified in genital fluid. Lactobacillus levels were quantified by real time PCR. Estrogen and progesterone levels in blood were determined by ELISA. Results Free glycogen was detected in both pre- and post-menopausal women. Across all samples, those from post-menopausal women had significantly lower levels of free glycogen than those from pre-menopausal women (median 0.002 vs. 0.065 µg/µl, respectively; p = 0.03). Lactobacillus levels correlated positively with free glycogen in both pre- (Spearman r=0.68, p <0.0001) and post-menopausal women (r=0.60, p <0.002). Samples from pre-menopausal women had higher Lactobacillus levels and a lower vaginal pH (median log=8.1; median pH= 4) than those from post-menopausal women (median log=7.1; median pH=4.6) although these differences were not significant. HIV status had no significant effect on these relationships. Conclusion Free glycogen was detected in both pre- and post-menopausal women and correlated with Lactobacillus in both groups. These results point to the complexity of the relationship between menopause and vaginal microbiota and indicate that more careful studies of the role played by glycogen are warranted.

Vaginal microbiota and genitourinary menopausal symptoms: a cross-sectional analysis

“…Mirmonsef et al showed a correlation between quantity of vaginal lactobacilli and free vaginal glycogen, but did not see a link between serum estrogen and either vaginal glycogen or Lactobacillus levels. 7 In Chinese women with and without vaginal signs and symptoms of atrophy, while serum estradiol levels were similar, relative proportion of vaginal lactobacilli was not. 6 These data, and our findings, suggest that there may not be direct links between serum estrogen, glycogen and Lactobacillus colonization as previously postulated.…”

“…3,4,6 Recent data have shown that free glycogen in vaginal fluid, which is liberated from epithelial cells by enzymes like α-amylase, is associated with Lactobacillus colonization in both pre- and postmenopausal women, suggesting glycogen may be a mediating factor for Lactobacillus presence. 7,8 In premenopausal women, serum estrogen levels were not correlated with free vaginal glycogen levels, but this relationship has not been examined in postmenopausal women. 9 …”

Chlamydia trachomatis Genital Tract Infections: When Host Immune Response and the Microbiome Collide

“…These changes were suggested to be dependent on estrogen levels, because the low pH and Lactobacillus spp. colonization in the vagina occur at the same time as when estrogen levels are increasing [94]. Gorodeski et al suggested that estrogen contributes to the acidification of the vaginal pH by upregulation of proton secretion via the apical membrane of vaginal ectocervical cells in their epithelial cell line model [95].…”

Genomic Comparisons of Lactobacillus crispatus and Lactobacillus iners Reveal Potential Ecological Drivers of Community Composition in the Vagina

“…The amount and composition of cervical mucus, as well as the amount of glycogen available, vary among women and through time in a single woman. Temporal variation in these characteristics occurs both on the scale of the menstrual cycle as well as through the lifetime of an individual (15)(16)(17)(18)(19). Additionally, the host can effect change in the vaginal communities via the immune system.…”