Effect of Menopausal Hormone Therapy on the Vaginal Microbiota and Genitourinary Syndrome of Menopause in Chinese Menopausal Women

Nationwide Observational Case-Control Study of Risk Factors for Aerococcus Bloodstream Infections, Sweden

Risk factors for developing bloodstream infections (BSIs) caused by Aerococcus bacteria remain insufficiently examined. In this nationwide case-control study in Sweden, 19 of 23 clinical microbiological laboratories identified patients who had aerococcal BSIs during 2012-2016. We compared each of those index patients with 4 controls matched for age, sex, and county of residence. Overall, 588 episodes of aerococcal BSI occurred over 39.6 million person-years, corresponding to an average incidence of 1.48/100,000 person-years (95% CI 1.37-1.60/100,000 person-years). Most infections developed in men >65 years of age. Aerococcal BSI was associated with neurologic (adjusted odds ratio 2.89 [95% CI 2.26-3.70]) and urologic (adjusted odds ratio 2.15 [95% CI 1.72-2.68]) conditions and previous hospitalization or infection treatment. Our findings support the previously observed predilection for aerococcal BSIs developing in elderly men with urinary tract disorders. Awareness of Aerococcus spp. in patients, especially elderly men, will be needed to manage invasive infections.

Deciphering the influence of gut and oral microbiomes on menopause for healthy aging

Menopause is characterized by the cessation of menstruation and a decline in reproductive function, which is an intrinsic component of the aging process. However, it has been a frequently overlooked field of women's health. The oral and gut microbiota, constituting the largest ecosystem within the human body, are important for maintaining human health and notably contribute to the healthy aging of menopausal women. Therefore, a comprehensive review elucidating the impact of the gut and oral microbiota on menopause for healthy aging is of paramount importance. This paper presents the current understanding of the microbiome during menopause, with a particular focus on alterations in the oral and gut microbiota. Our study elucidates the complex interplay between the microbiome and sex hormone levels, explores microbial crosstalk dynamics, and investigates the associations between the microbiome and diseases linked to menopause. Additionally, this review explores the potential of microbiome-targeting therapies for managing menopause-related diseases. Given that menopause can last for approximately 30 years, gaining insights into how the microbiome and menopause interact could pave the way for innovative interventions, which may result in symptomatic relief from menopause and an increase in quality of life in women.

Vaginal microbiota transplantation alleviates vaginal atrophy in ovariectomized mice

Vaginal atrophy is a prevalent symptom in menopausal women, affecting over 50% of older women and patients with loss of ovarian function. The role of factors other than estrogen, such as the vaginal microbiota (VM), in the development of vaginal atrophy has not been fully explored. Therefore, we selected 8-week-old C57 mice with bilateral ovariectomy for experimentation. After four weeks of treatment, we observed that the vaginal epithelium of ovariectomized mice showed signs of atrophy. There were also significant differences in the structure and metabolites of VM. Vaginal transplantation of microbiota from ovary-intact mice significantly alleviated the vaginal atrophy of ovariectomized mice and altered the structure and metabolism of VM. These findings indicate that ovarian activity significantly affects the structure and metabolism of VM. VM of ovary-intact mice may promote vaginal health by upregulating the estrogen receptor alpha gene (ESR1, one-way ANOVA, F4, 25 = 17.76, P < 0.0001) in vaginal epithelial cells in ovariectomized mice, which in turn promotes cell proliferation (the number of vaginal epithelial cell layers, one-way ANOVA, F4, 25 = 28.04, P < 0.0001). Further studies are needed to investigate the interactions between VM and vaginal health. This finding can help develop new therapeutic strategies and interventions for patients suffering from vaginal atrophy.

Vaginal microbiota, menopause, and the use of menopausal hormone therapy: a cross-sectional, pilot study in Chinese women

OBJECTIVE

To compare the vaginal microbiota of premenopausal and postmenopausal women and postmenopausal women undergoing menopausal hormone therapy (MHT) and examine the association between vaginal microbiota and genitourinary syndrome of menopause (GSM).

METHODS

This cross-sectional study classified 94 women aged 40 to 60 years into three groups: premenopausal (Pre, n = 32), postmenopausal (Post, n = 30), and postmenopausal women who received MHT orally (Post + MHT, n = 32). Neither the Pre nor the Post group received hormone therapy within the past 6 months. Postmenopausal women who received vaginal MHT were not included. Vaginal swabs were obtained, and microbial composition was characterized by 16S rRNA gene sequencing targeting the V3 to V4 region. Clinical data were collected and serum sex hormones were measured. The most bothersome symptom approach and vaginal health index were used to evaluate GSM. Mann-Whitney U or Kruskal-Wallis ANOVA followed by multiple comparison tests were performed for comparison between or across groups. The correlations between GSM symptom scores and vaginal microbiota were determined using Spearman's correlation analysis.

RESULTS

The vaginal community of postmenopausal women was characterized by a decreased abundance of Lactobacillus (Post 18% vs Pre 69%); an increased abundance of several anaerobic bacteria, including Prevotella , Escherichia-Shigella , and Bifidobacterium ; and a higher microbial diversity ( P < 0.001 for Shannon and Simpson indexes) than those of premenopausal women. The vaginal community of postmenopausal women who received MHT had an increased abundance of Lactobacillus (54%) and lower microbial diversity ( P < 0.001 for Shannon and Simpson indexes) than the postmenopausal women. The vaginal microbial community composition of the Pre group shared more similarity with that of the Post + MHT group (Adonis P = 0.051) than with that of the Post group (Adonis P < 0.001). A decreased abundance of Lactobacillus and high diversity in the vaginal community were found in women with moderate to severe GSM symptoms.

CONCLUSIONS

Among Chinese postmenopausal women, those receiving MHT had higher Lactobacillus abundance but lower abundance of diverse anaerobes and diversity of the vaginal microbial community compared to non-MHT women. MHT in postmenopausal women may potentially contribute to reestablishing vaginal microbiota homeostasis. Findings in this pilot study, however, need to be examined in larger, prospective studies.

Exploring menopausal symptoms, attitudes, and behaviors among menopausal women in China: an online research perspective

OBJECTIVE

The number of perimenopausal women in China is rising, but the population's concept of menopausal hormone therapy (MHT) is still relatively outdated.

METHODS

In this study, we used the Knowledge-Attitude-Practice (KAP) theory and collected online questionnaires from 1,100 women aged 40 to 60 years nationwide to find out their menopausal symptom profiles; to learn about their perceptions, attitudes, and behaviors toward menopause and MHT; to explore the factors influencing the acceptance of hormone treatments; and to look for better ways to promote the dissemination of menopausal knowledge.

RESULTS

The results revealed that among women aged 40 to 60 years, 82.36% experienced possible menopausal symptoms, with hot flushes/sweating, sleep disorders, mood disorders, and fatigue being the most prevalent; 55.90% reported moderate to severe symptoms, but only 46.99% of them sought healthcare services. Among those who sought medical care, 16.00% had their first visit to climacteric clinics/gynecological endocrinology, and 5.66% accepted MHT. Furthermore, 77.82% of participants never heard of MHT or were unaware of its existence. The healthcare-seeking behavior of menopausal women in response to symptoms and their willingness to accept MHT were found to be closely associated with their level of self-care.

CONCLUSIONS

The prevalence of menopausal symptoms is higher in China than previous research findings, but due to a lack of relevant knowledge, the rate of seeking treatment from the appropriate medical department and accepting MHT is relatively low. Enhancing physicians' knowledge of the menopausal transition and using Internet tools might help improve Chinese women's knowledge of menopause and help them pass through this period smoothly.

Associations of vaginal microbiota with the onset, severity, and type of symptoms of genitourinary syndrome of menopause in women

Introduction

Genitourinary syndrome of menopause (GSM) describes the symptoms and signs resulting from the effect of estrogen deficiency on the female genitourinary tract, including genital, urinary, and sexual symptoms. However, besides estrogen deficiency, little is known about the etiology of GSM. The objective of this study was to investigate the effects of vaginal microbiota dysbiosis on the occurrence and development of GSM in perimenopausal and postmenopausal women.

Methods

In total, 96 women were enrolled in this cross-sectional study and clinical data were collected. GSM symptoms were divided into three types: genital, urological, and sexual symptoms. Full-length 16S rRNA gene sequencing using the third-generation PacBio sequencing technology was performed to analyze the vaginal microbiome using vaginal swabs of non-GSM and GSM women with different types of GSM symptoms. Live Lactobacillus Capsule for Vaginal Use (LLCVU) treatment was used to verify the effects of Lactobacillus on GSM symptoms.

Results

We found that 83.58% (56/67) of women experienced GSM symptoms in the perimenopausal and postmenopausal stages. Among these women with GSM, 23.21% (13/56), 23.21% (13/56), and 53.57% (30/56) had one type, two types, and three types of GSM symptoms, respectively. The richness and diversity of vaginal microbiota gradually increased from reproductive to postmenopausal women. There were significant differences in vaginal microbial community among non-GSM women and GSM women with different types of symptoms. Lactobacillus was found to be negatively associated with the onset, severity, and type of GSM while some bacteria, such as Escherichia-shigella, Anaerococcus, Finegoldia, Enterococcus, Peptoniphilus_harei, and Streptococcus, were found to be positively associated with these aspects of GSM, and these bacteria were especially associated with the types of genital and sexual symptoms in GSM women. LLCVU significantly relieved genital symptoms and improved the sexual life of GSM women in shortterm observation.

Conclusions

The onset, severity, and type of GSM symptoms may be associated with changes in vaginal microbiota in perimenopausal and postmenopausal women. Vaginal microbiota dysbiosis probably contributes to the occurrence and development of GSMsymptoms, especially vaginal and sexual symptoms. Lactobacillus used in the vagina may be a possible option for non-hormonal treatment of GSM women with genital and sexual symptoms.

Clinical Trial Registration

https://www.chictr.org.cn/indexEN.html, identifier ChiCTR2100044237.

Association between vaginal microbiota and vaginal inflammatory immune markers in postmenopausal women

OBJECTIVE

In premenopausal individuals, vaginal microbiota diversity and lack of Lactobacillus dominance are associated with greater mucosal inflammation, which is linked to a higher risk of cervical dysplasia and infections. It is not known if the association between the vaginal microbiota and inflammation is present after menopause, when the vaginal microbiota is generally higher-diversity and fewer people have Lactobacillus dominance.

METHODS

This is a post hoc analysis of a subset of postmenopausal individuals enrolled in a randomized trial for treatment of moderate-severe vulvovaginal discomfort that compared vaginal moisturizer, estradiol, or placebo. Vaginal fluid samples from 0, 4, and 12 weeks were characterized using 16S rRNA gene sequencing (microbiota) and MesoScale Discovery (vaginal fluid immune markers: IL-1b, IL-1a, IL-2, IL-6, IL-18, IL-10, IL-9, IL-13, IL-8, IP10, MIP1a, MIP1b, MIP3a). Global associations between cytokines and microbiota (assessed by relative abundance of individual taxa and Shannon index for alpha, or community, diversity) were explored, adjusting for treatment arm, using linear mixed models, principal component analysis, and Generalized Linear Mixed Model + Microbiome Regression-based Kernel Association Test (GLMM-MiRKAT).

RESULTS

A total of 119 individuals with mean age of 61 years were included. At baseline, 29.5% of participants had a Lactobacillus -dominant vaginal microbiota. Across all timepoints, alpha diversity (Shannon index, P = 0.003) was highly associated with immune markers. Individual markers that were associated with Lactobacillus dominance were similar to those observed in premenopausal people: IL-10, IL-1b, IL-6, IL-8 (false discovery rate [FDR] < 0.01), IL-13 (FDR = 0.02), and IL-2 (FDR = 0.09). Over 12 weeks, change in alpha diversity was associated with change in cytokine concentration (Shannon, P = 0.018), with decreased proinflammatory cytokine concentrations observed with decreasing alpha diversity.

CONCLUSIONS

In this cohort of postmenopausal individuals, Lactobacillus dominance and lower alpha diversity were associated with lower concentrations of inflammatory immune markers, as has been reported in premenopausal people. This suggests that after menopause lactobacilli continue to have beneficial effects on vaginal immune homeostasis, despite lower prevalence.

Effects of Guizhi and Erxian Decoction on menopausal hot flashes: insights from the gut microbiome and metabolic profiles

AIMS

To examine the influence of GED on the gut microbiota and metabolites using a bilateral ovariectomized (OVX) rat model. We tried to elucidate the underlying mechanisms of GED in the treatment of menopausal hot flashes.

METHODS AND RESULTS

16S rRNA sequencing, metabonomics, molecular biological analysis, and fecal microbiota transplantation (FMT) were conducted to elucidate the mechanisms by which GED regulates the gut microbiota. GED significantly reduced OVX-induced hot flashes and improved disturbances in the gut microbiota metabolites. Moreover, FMT validated that the gut microbiota can trigger hot flashes, while GED can alleviate hot flash symptoms by modulating the composition of the gut microbiota. Specifically, GED upregulated the abundance of Blautia, thereby increasing l(+)-ornithine levels for the treatment of menopausal hot flashes. Additionally, GED affected endothelial nitric oxide synthase and heat shock protein 70 (HSP70) levels in the hypothalamic preoptic area by changing the gut microbiota composition.

CONCLUSIONS

Our study illuminated the underlying mechanisms by which GED attenuated the hot flashes through modulation of the gut microbiota and explored the regulatory role of the gut microbiota on HSP70 expression in the preoptic anterior hypothalamus, thereby establishing a foundation for further exploration of the role of the gut-brain axis in hot flashes.

The Postmenopausal Vaginal Microbiome and Genitourinary Syndrome of Menopause

This review summarizes our current understanding of associations of the postmenopausal vaginal microbiome with genitourinary syndrome of menopause. We review the normal postmenopausal microbiota, examine the association of the microbiome with vulvovaginal symptoms, describe microbial communities associated with physical and laboratory findings, and report the impact of different treatments for genitourinary syndrome of menopause on microbiota and symptom improvement. Postmenopausal vaginal symptoms have an underlying pathophysiology that has not been fully elucidated. Estrogen treatment may not be sufficient to relieve symptoms of vaginal discomfort in all postmenopausal individuals. In addition, other interventions targeted at changing the microbiota or pH do not consistently improve symptom severity.

Human vaginal microbiota colonization is regulated by female sex hormones in a mouse model

Introduction

Clinically, a Lactobacillus rich vaginal microbiota (VMB) is considered optimal for reproductive outcomes, while a VMB populated by anaerobes is associated with dysbiosis and the clinical condition bacterial vaginosis (BV), which is linked to increased susceptibility to sexually transmitted infections and adverse reproductive outcomes. Mouse models that mimic eubiotic and dysbiotic VMB are currently lacking but could play a critical role in improving protective interventions.

Methods

In this study, probiotic, eubiotic, and dysbiotic models were developed in C57BL/6 mice, using probiotic strains Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14, eubiotic Lactobacillus crispatus, or dysbiotic Gardnerella vaginalis strains. Endogenous sex hormones were manipulated by either ovariectomizing (OVX) mice or administering 17β-estradiol or progesterone pellets in OVX mice. Hormone-altered mice were inoculated with probiotic Lactobacillus species, L. crispatus, or G. vaginalis, and colonization was tracked using quantitative plating assays. Glycogen and MUC-1 levels in hormone-treated mice were determined with ELISA and MUC-1 staining.

Results

Following a single administration, L. rhamnosus and L. reuteri persisted in the mouse vaginal tract for up to eight days, L. crispatus persisted for up to three days, and G. vaginalis persisted for up to two days, as measured by quantitative plating assays and qPCR. Colonization of G. vaginalis was facilitated by the presence of mucin. The lack of endogenous hormones in OVX mice dramatically decreased VMB bacterial load compared to normal mice. None of the exogenous bacteria including Lactobacilli could colonize OVX mice for more than 24 hours. Treatment with 17β-estradiol but not progesterone restored the endogenous VMB and colonization with Lactobacilli and G. vaginalis. Interestingly, 17β-estradiol treated mice had significantly increased levels of glycogen compared to OVX and progesterone-treated mice.

Discussion

Based on the results, we have shown that estrogen played a significant role in the ability for human VMB species to colonize in our mouse models, potentially through a glycogen mediated mechanism. These results suggest there is a dynamic interaction between sex hormones and the VMB, which can affect bacterial diversity and the ability for a VMB to colonize.

Bacterial Vaginosis in Postmenopausal Women

Purpose of Review

Bacterial vaginosis (BV) is the most common vaginal infection worldwide, but most research has been conducted in premenopausal women. After menopause, endogenous estrogen production decreases, often leading to the genitourinary syndrome of menopause (GSM), characterized by vulvovaginal dryness and irritation. The estrogen-deficient postmenopausal state results in an elevated vaginal pH and depletion of vaginal lactobacilli. Use of traditional BV diagnostics (Amsel criteria, Nugent score) is difficult in post-menopausal women, especially those not on estrogen replacement therapy, as these methods were originally developed in premenopausal women. In this review, we discuss recent clinical data on BV in postmenopausal women, difficulties in diagnosis using traditional methods, the role of BV molecular diagnostics, and our current expert opinion for managing BV in this population.

Recent Findings

BV prevalence has been found to range between 2%-57% among postmenopausal women per Amsel and Nugent criteria. This is likely an over-estimate of the true prevalence due to limitations in these criteria which were only validated in pre-menopausal women. Despite increasing diagnostic options for BV in recent years, including highly sensitive and specific BV nucleic acid amplification tests (NAATs), the physiologic changes of menopause and limited inclusion of postmenopausal women in clinical studies, diagnosis is difficult in this population. Recent studies utilizing 16s rRNA gene sequencing suggest that the vaginal microbiota of premenopausal and postmenopausal women is quite different, even if BV is not present. Data also suggest that obese postmenopausal women have significantly lower rates of BV compared to non-obese postmenopausal women, although further research is needed in this area. Multiple treatment options exist for vaginal atrophy and BV in this population.

Summary

Data are limited regarding optimal diagnostic approaches for BV in postmenopausal women; BV NAATs and 16s rRNA gene sequencing may have a role for diagnosing BV in symptomatic women although further studies are needed. Menopausal women with characteristic vaginal symptoms and an elevated vaginal pH should be initially treated for estrogen deficiency prior to considering a diagnosis of BV; subsequent treatment for BV should be driven by symptoms.

The Importance of the Microbiota in Shaping Women’s Health—The Current State of Knowledge

According to current knowledge, a properly colonized human microbiota contributes to the proper functioning of the body. The composition of the natural flora changes depending on age, health, living conditions, and the use of antimicrobial agents: antibiotics, disinfectants, and some cosmetics. The human body is diversely populated with microorganisms and undergoes constant changes under the influence of various factors, and its proper composition is extremely important for the proper functioning of the body. Given the above, it was decided that we would review current scientific research that explains the cause–effect relationship between the composition of microorganisms populating the human body and health, focusing on women’s health. As a result, an overview paper was prepared based on 109 scientific sources from 2009–2022. Special attention was paid to the most recent scientific studies of the last five years, which account for more than 75% of the cited sources.

The relationship between pelvic floor functions and vaginal microbiota in 6-8 weeks postpartum women

The impairment of pelvic floor muscle functions and Lactobacillus-deficient vaginal microbiota is common in postpartum women. However, few studies have explored the correlation between pelvic floor muscle functions and vaginal microbiota. Given this research gap, our study aims to investigate any potential association between these two conditions of postpartum women (6-8 weeks after childbirth). A total of 230 women who required postpartum pelvic floor function examination at Peking University International Hospital from December 2021 to April 2022 were enrolled in this study. The collected questionnaire information included progestational weight, body mass index (BMI), weight gain during pregnancy, neonatal weight, delivery type, multiparity, postpartum time, and urinary incontinence (UI). A total of 187 samples of vaginal secretions were collected, and the vaginal microbiota was detected by 16S rRNA sequence analysis. Finally, 183 samples were analyzed in the trial. All individuals were divided into two groups according to the results of pelvic floor muscle assessment to explore the difference between the incidence of postpartum urinary incontinence and vaginal microbiota. We found that the prevalence of UI was higher in the group with weakened pelvic floor muscles. Vaginal delivery, overweight, age, neonatal weight, and weight gain during pregnancy were all risk factors for postpartum urinary incontinence. The vaginal microbiome was no longer Lactobacillus dominant of most postpartum women (91.8%), while the diversity of microbiota increased. The Lactobacillus-deficient community, commonly labeled as community state type (CST) IV, was sub-divided into four communities. The abundance of vaginal Lactobacillus decreased in the group with compromised pelvic muscle functions, while the species richness and diversity increased significantly. In conclusion, the decreased pelvic floor muscle functions of postpartum women 6-8 weeks after delivery may disrupt the balance of vaginal microbiota, and the restoration of pelvic floor functions may contribute to a healthy and balanced vaginal microbiota.

Association of Cervical Dysbacteriosis, HPV Oncogene Expression, and Cervical Lesion Progression

As the fourth most common gynecological cancer, cervical cancer has resulted in more than 300,000 deaths worldwide in 2020. The expression of the human papillomavirus (HPV) oncogenes E6 and E7 is significantly involved in the initiation and progression of cervical neoplasia. Additionally, the composition of the vaginal microbiome was also closely associated with the ability of HPV to induce cervical cancer. However, the relationship between the expression of HPV E6/E7 oncogene and the composition of the vaginal microbiome has not been clearly explored. In our present study, to investigate the relationship between the HPV E6/E7 oncogene and vaginal microbiome, cervical swabs from 115 patients were collected, and their vaginal microbiomes were analyzed by using metagenomics sequencing. Along with the progression of cervical lesions, the diversity of cervical flora increased gradually, and the abundance of Lactobacillus decreased. Compared with the HPV group, the prevalence of HPV E6/E7 and oncogene expression level were significantly upregulated in cervical intraepithelial neoplasia (CIN) and cervical cancer (CC) groups. Additionally, a positive correlation between the expression of the HPV oncogene and the genera Sneathia, Salmonella, Leptotrichia, Pseudomonas, and Roseovarius in the HPV group was observed. In the CIN group, the enrichment of the genera Sneathia and Megasphaera was weakly linked with HPV oncogene overexpression. In the CC group, a strong association between the overabundance of the genera Peptostreptococcus and Enterococcus and the high expression of HPV oncogene was also found. The increased diversity of the vaginal microbiota and the decreased Lactobacillus abundance were significantly associated with the severity of cervical disease, and the expression of the HPV oncogene could also be regulated by certain pathogens in different stages of cervical lesions.

IMPORTANCE The main findings of this study were that we clarified the associations of the different bacterial species with the expression of human papillomavirus (HPV) oncogenes at different stages of cervical cancer. Along with the severity of cervical lesions, the abundance of the genus and species of Lactobacillus obviously declined, while the aerobic and anaerobic bacteria, as well as the prevalence and expression of HPV E6/E7 oncogene, were increased dramatically.