Surprising effects of menopause on microbiota

How do the hormonal changes associated with menopause alter oral, gut, and urogenital microbiota composition? To answer this question, a team of Spanish researchers analyzed more than 100 studies on the subject. 

Published in the journal npj Women Health ¹, their analysis shows that the decline in sex hormones (estrogen and progesterone) significantly alters mucous membranes, with multiple impacts on the body’s various bacterial communities. Unsurprisingly, this has an impact on women’s health.

Oral microbiota

Changes related to declining estrogen levels are particularly noticeable in the oral cavity. In addition to changes in the mucous membrane that disrupt microbial communities, there is a decrease in the quantity and quality of saliva, which becomes more acidic. 

These two alterations can promote inflammation and colonization of the oral flora by pathogenic bacteria. This disrupted microbiota is less balanced, increasing the risk of lesions and diseases such as candidiasis (proliferation of Candida albicans), gingivostomatitis (inflammation of the gums), and angular cheilitis (inflammation of the corners of the mouth).

Vaginal microbiota

The decline in estrogen reduces the glycogen content of the cells in the vaginal wall, glycogen being the preferred food source for lactobacilli. These bacteria usually dominate the vaginal microbiota, secreting lactic acid which acidifies the vagina and prevents the proliferation of pathogens. 

When lactobacilli become less abundant, the vagina becomes less acidic and bacterial diversity increases. This is known as the “menopause paradox.” This imbalance in the vaginal flora opens the door to disorders such as inflammation, or recurrent infections such as bacterial vaginosis, and may contribute to endometrial cancer. It may also lead to persistent dryness. 

Gut microbiota

Studies to date do not tell us whether the decline in estrogen affects the balance of the gut microbiota. However, we do know that postmenopausal women have lower levels of bacteria from the Ruminococcus family, some of which produce beneficial short-chain fatty acids (SCFAs (sidenote: Short chain fatty acids (SCFA) Short chain fatty acids (SCFA) are a source of energy (fuel) for an individual’s cells. They interact with the immune system and are involved in communication between the intestine and the brain. Silva YP, Bernardi A, Frozza RL. The Role of Short-Chain Fatty Acids From Gut Microbiota in Gut-Brain Communication. Front Endocrinol (Lausanne). 2020;11:25. ) ). They also have a greater abundance of Prevotella and Sutterella, two bacteria associated with obesity.

This imbalance in the gut flora may contribute to certain metabolic, digestive, and immune disorders. A balanced gut flora appears to play an essential role in overall health, including hormone regulation.

Take care of your microbiota

While further studies are needed before specific treatments targeting microorganisms in the gut, vagina, and mouth can be recommended for postmenopausal women (e.g. probiotics tailored to each flora, dietary changes, etc.), limiting damage by taking care of your microbiota seems a good place to start. 

A varied diet rich in fiber and fermented foods, daily physical activity, if possible in a natural environment, giving up smoking and alcohol, and using antibiotics as sparingly as possible: all have proven beneficial effects on the microbiota.

A healthy, balanced lifestyle is thus a sure way to support the balance of the microbial flora during menopause.