Postmenopause: treating symptoms while preserving the vaginal microbiota

Menopause

Estradiol vaginal tablets or intimate moisturizer?
Although both appear equally effective in relieving symptoms of the menopause, their impact on the vaginal microbiota varies considerably.

About this article

Created 01 June 2022

Updated 09 June 2022

Vaginal dryness, itching, frequent urination, pain during intercourse... The period following menopause (postmenopause) is not always easy.
Genitourinary syndrome of menopause (GSM)¹ is a condition whose symptoms can mostly be attributed to the estrogen deficiency typical of menopause. Displaying various degrees of severity, the condition can be treated via hormonal treatments such as estradiol vaginal tablets, or non-hormonal treatments such as vaginal moisturizers.
The question is, what impact do these treatments have on vaginal pH, the vaginal microbiota, and metabolites produced by the microorganisms contained in it?

Menopause and postmenopause

Menopause is the cessation of ovulation and menstruation due to the interruption of estrogen and progesterone secretion.⁴ It generally occurs around the age of 50. The period that follows is known as the postmenopause⁵, which is characterized by the onset of various symptoms (hot flushes, sleep disturbance, fatigue, irritability, vaginal dryness, etc.) and an increased risk of certain diseases (osteoporosis, cardiovascular disease⁶).

Importance of vaginal microbiota for health

We know that the bacteria in the vaginal microbiota contribute to maintaining a healthy vaginal environment. Unlike the gut microbiota, the vaginal microbiota is balanced when it is not very diverse and is composed mainly of lactobacilli. Some of these bacteria produce lactic acid, which maintains the vagina’s acidic pH (pH ≤ 4.5), thus preventing the growth of pathogens. At menopause, estrogen levels decrease significantly. As a result, vaginal pH increases and the vaginal flora undergoes a change (fewer lactobacilli and greater bacterial diversity).²

The vaginal microbiota

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Treatments have different impact on vaginal microbiota

This new clinical study³ involved 144 postmenopausal women (mean age 64) experiencing moderate to severe vulvovaginal discomfort. The researchers compared the impact on the microbiota of an estradiol vaginal tablet, a moisturizing gel, and a double placebo (tablet and gel with no active compound).

At 12 weeks, 80% of women in the estradiol group had vaginal bacterial communities dominated by Lactobacillus and Bifidobacterium, compared to only 36% in the moisturizer group and 26% in the placebo group. Moreover, in the women treated with estradiol, more than half of the metabolites in the vaginal fluid changed, with an increase in lactate production almost certainly contributing to the marked decrease in pH in this group.

Estradiol for a healthy intimate area

The effect of estradiol was more pronounced in women who initially had a very diverse vaginal microbiota (considered less healthy) and a high vaginal pH. According to the researchers, this hormone may stimulate the metabolic activity of beneficial lactic acid-producing bacteria, such as lactobacilli and bifidobacteria, which in turn lowers vaginal pH. They thus suggest that estradiol tablets should be prioritized, since they may offer additional benefits for genitourinary health in postmenopausal women.

Sources

^{1 Angelou K, Grigoriadis T, Diakosavvas M, et al. The Genitourinary Syndrome of Menopause: An Overview of the Recent Data. Cureus. 2020 Apr 8;12(4):e7586.}

^{2 Greenbaum S, Greenbaum G, Moran-Gilad J, et al. Ecological dynamics of the vaginal microbiome in relation to health and disease. Am J Obstet Gynecol. 2019 Apr;220(4):324-335.}

^{3 Srinivasan S, Hua X, Wu MC, et al. Impact of Topical Interventions on the Vaginal Microbiota and Metabolome in Postmenopausal Women: A Secondary Analysis of a Randomized Clinical Trial. JAMA Netw Open. 2022 Mar 1;5(3):e225032.}

^{4 O’Neill S., Eden J. The pathophysiology of menopausal symptoms. Obstetrics, Gynaecology & Reproductive Medicine 2017 Oct;27(10):303-310}

^{5 Koothirezhi R, Ranganathan S. Postmenopausal Syndrome. [Updated 2022 Apr 28]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-.}

^{6 Rossi R, Grimaldi T, Origliani G, et al. Menopause and cardiovascular risk. Pathophysiol Haemost Thromb. 2002 Sep-Dec;32(5-6):325-8.}