Menopause: unbalanced vaginal microbiota may promote inflammation
A study on menopausal women suggests that it may one day be possible to reduce inflammation of the vaginal mucosa by modulating the vaginal microbiota. Crucially, this could reduce the risk of infection and cervical cancer.
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About this article
At menopause, the vaginal microbiota may play a key role in women’s gynecological health.
Under normal circumstances, lactic acid bacteria called Lactobacillus, found in abundance in the vaginal flora, acidify the vaginal environment, helping to balance the microbiota.
45 to 55 the age at which the menopause transition most often begins ¹
87% of women experience at least one symptom in addition to the cessation of menstruation ²
20-25% suffer severe disorders affecting quality of life ²
How menopause modifies vaginal microbiota
During the premenopause (the period before menstruation ceases for good, see text box), the drop in estrogen levels leads to a reduction in the glycogen content of the mucosal cells, glycogen being the preferred food of Lactobacillus.
Less well nourished, Lactobacillus become less abundant and lose their dominant position in the flora, which can lead to imbalances in the vaginal microbiota ( (sidenote: Dysbiosis Generally defined as an alteration in the composition and function of the microbiota caused by a combination of environmental and individual-specific factors. Levy M, Kolodziejczyk AA, Thaiss CA, et al. Dysbiosis and the immune system. Nat Rev Immunol. 2017;17(4):219-232. ) ). The reduction in sex hormones is also associated with a harmful increase in microbial diversity.
55% of women are aware that from childhood to menopause, a woman's vaginal microbiota does not remain the same.
Several studies have shown that the loss of Lactobacillus dominance and the increase in bacterial diversity are associated with inflammation of the vaginal mucosa. Inflammation increases the risk of infection, particularly with sexually transmitted infections (STIs), and of precancerous cervical lesions.
While the link between changes in the vaginal microbiota and inflammation has been shown in premenopausal women, no study has yet been carried out to determine whether it persists in the postmenopausal period (see text box).
Modulating the vaginal microbiota to preserve health?
To document this, a team of US researchers used data from 119 postmenopausal women (average age 61) who had taken part in a clinical trial comparing the effects of estrogen or a moisturizing cream on the vaginal flora.
They analyzed both bacterial populations and markers of inflammation (cytokines) in the volunteers’ vaginal fluids to determine whether these two parameters were linked. 3
They found that the women whose vaginal microbiota was the most diverse, or the most depleted in Lactobacillus, had the highest levels of cytokines. These two characteristics of the vaginal microbiota are therefore associated with inflammation, as in premenopausal women.
The vaginal microbiota
These results are interesting, since they suggest that it may one day be possible, by modulating the vaginal microbiota of postmenopausal women, to limit inflammation of the vaginal mucosa, and thus act preventively to preserve their health.
