Probiotics, allies for menopausal women?

The menopause is biologically characterised by the cessation of menstruation due to a drastic decrease in the production of oestrogen and progesterone by the ovarian follicles. This reduction significantly alters the vaginal microbiota, that is, the collection of microorganisms (bacteria, yeasts, viruses...) living in the vagina. Research has shown that the transition to menopause is associated with a decrease in Lactobacillus bacteria , which disrupts the balance of the microbiota. Before menopause, these bacteria dominate the vaginal microbiota and represent 90% of the microorganism population.

From puberty to menopause, the increase in oestrogen levels promotes the growth of these lactic acid-producing bacteria, resulting in the creation of a protective acidic environment. Menopause increases bacterial diversity in the vagina, thus promoting the occurrence of symptoms such as vaginal dryness and vulvo-vaginal atrophy. Indeed, while these phenomena largely result directly from the decrease in oestrogen levels, many researchers have shown that they can also be attributed to changes in the vaginal microbiota.

Probiotics are microorganisms introduced through diet or topically that can confer benefits to the body. They are particularly effective in restoring the homeostasis of the vaginal microbiota. The mechanisms of action of probiotics are diverse and include improving the barrier function, blocking the adhesion of pathogenic bacteria, reducing pH, and altering the overall immunity of the mucosa and vaginal health. The oral and vaginal routes of administration have been the subject of clinical studies aimed at restoring vaginal homeostasis through the administration of probiotic formulations based on Lactobacillus.

Although it has not been specifically studied in menopausal women, a recent study examined the composition of the vaginal microbiota in pre-menopausal women before and after the vaginal instillation of probiotics. Samples taken after six months of probiotic administration revealed that the majority of participants showed a change in their bacterial microbiota in favour of Lactobacillus compared to samples taken before the study. This suggests that the instillation of such probiotics after menopause could have a rebalancing effect on the vaginal microbiota.

Another study highlighted the benefits of oral intake of probiotics Lactobacillus rhamnosus and Lactobacillus reuteri on the quality of the vaginal flora in 72 menopausal women. These women were divided into two groups. One group received the probiotics once a day for 14 days while the other received a placebo. Final vaginal swabs were taken one day after the last tablet administration and the Nugent score was measured. This score ranges from 0 to 10 and reflects the quality of the vaginal microbiota: if it is between 0 and 3, the flora is balanced and predominantly Lactobacillus, if it is between 4 and 6, the flora is slightly altered, and if it is 7 or above, bacterial vaginosis is considered. At the end of the study, 60% of the women in the first group showed a reduction in the Nugent score of at least two levels.

The findings from various studies demonstrate a genuine interest in probiotics for restoring the vaginal flora in menopausal women.

In addition to an imbalance in their vaginal microbiota, menopausal women are often prone to osteoporosis. This bone disease is a direct consequence of the decrease in the amount of oestrogens in the body during menopause. It is characterised by a reduction in bone mass and a degradation of the tissue structure that composes it, which significantly increases the risk of fractures. According to a study conducted among menopausal women, about 6 out of 10 women have suffered one or more fractures during the first 5 years following their menopause. Moreover, recent research has highlighted a close relationship between the microbiota and bone health, thus suggesting a potential benefit of probiotics for strengthening bones.

In a 12-month double-blind, placebo-controlled study, 90 women aged between 75 and 80 years suffering from osteopenia were divided into two groups to receive a daily oral supplementation of Lactobacillus reuteri or a placebo. For your information, osteopenia is a decrease in bone density and is a precursor state to osteoporosis. At the end of the study, scientists observed a reduction in the loss of body mass density and an enhancement of bone health in those who received the probiotic. These results highlight the potential benefits of such supplementation in older women suffering from osteopenia.

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• KISS H. & al. Randomised, double-blind, placebo-controlled study of oral lactobacilli to enhance the vaginal flora of postmenopausal women. European Journal of Obstetrics, Gynaecology and Reproductive Biology (2008).

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• MUELLER E. & al. Oral probiotics and the female urinary microbiome: a double-blinded randomised placebo-controlled trial. International Urology and Nephrology (2019).

• MUSCOGIURI G. & al. Probiotics and Prebiotics: Do They Have a Role in Diseases Related to Menopause? Current Nutrition Reports (2023).