Gut health and menopause: the estrobolome, explained carefully

There is a genuine two-way relationship between oestrogen and the gut microbiome. A subset of gut bacteria produces beta-glucuronidase, an enzyme that reactivates oestrogen the liver had prepared for excretion, allowing it to be reabsorbed. That collection of bacteria is called the estrobolome, and microbiome diversity does decline after menopause in studies. What does not follow is that a probiotic corrects it, and that gap is where a large supplement market sits.

Published 19 September 2026

What the estrobolome actually is

The liver deactivates oestrogen by attaching a glucuronide group to it, packaging it for excretion through bile into the gut.

Certain gut bacteria produce beta-glucuronidase, which removes that group and reactivates the oestrogen, allowing it to be reabsorbed into circulation rather than excreted.

The collection of gut bacteria with this capability is termed the estrobolome. It is a real and described mechanism, and it means the gut has some influence over circulating oestrogen levels.

What changes after menopause

Studies find reduced microbiome diversity in postmenopausal compared with premenopausal women, and a shift in the balance of bacterial populations. Postmenopausal microbiomes more closely resemble those of men of similar age.

The relationship runs both ways, which is what makes it interesting: oestrogen influences the microbiome, and the microbiome influences oestrogen. Neither is simply upstream of the other.

Lower diversity is generally associated with poorer metabolic health, though association is not the same as causation and the direction of effect is genuinely unresolved.

Where the evidence stops

This is the part usually left out. Several things are described but not demonstrated:

That taking a probiotic meaningfully changes the estrobolome, which has not been shown
That any specific probiotic strain improves menopausal symptoms, where trial evidence is thin and inconsistent
That a microbiome test can tell you which supplement you need, which is not supported by any validated clinical use
That gut dysbiosis causes menopausal symptoms, which reverses an association into a causal claim the data does not carry

What does have evidence

Dietary fibre diversity is the best-supported influence on microbiome composition. Studies consistently associate a wider range of plant foods with greater bacterial diversity, and fibre is the substrate those bacteria depend on.

Fermented foods have reasonable evidence for increasing microbiome diversity and reducing inflammatory markers, better evidence than most probiotic supplements.

Alcohol reduces diversity. Repeated antibiotic courses reduce it, and recovery takes months. Sleep disruption and chronic stress both affect composition through documented routes.

None of this is menopause-specific. It is ordinary gut health advice, which is the honest answer: the estrobolome is real, and the practical implications are the same as they would be anyway.

When to see someone

See a clinician rather than buying a test for persistent bloating, a change in bowel habit lasting more than three weeks, blood in the stool, or unexplained weight loss.

Ask for coeliac serology before removing gluten from your diet, since testing is unreliable once gluten has been excluded, and this is the most common way a coeliac diagnosis is delayed by years.

Wondering if this is perimenopause?

Two free next steps: check where your symptoms and cycle sit against the clinical criteria, or go straight to clinicians who treat this every day.

Take the 12-question self-check Find a perimenopause specialist

Sources

This page is general information, not medical advice, and it does not recommend or rule out any treatment for you personally. If something here contradicts what your clinician tells you, your clinician knows your situation — this page does not.