Gut Microbiome and Menopause: What We Know and What Remains Uncertain

A 2026 review did not find a consistent link between oestrogen levels and broad patterns in gut bacteria. Other factors may have affected the results.

The gut microbiome is the community of bacteria and other tiny organisms that live in the digestive system. Interest in how it may relate to menopause has grown quickly.

You may also have seen the term “estrobolome”. Researchers use this word for genes and enzymes made by gut microbes that may help the body process oestrogen. This is still an area of research. It is not a proven explanation for an individual person’s menopause symptoms, and it is not a routine diagnosis.

The main finding

A 2026 review combined results from seven studies. It compared gut bacteria in people after menopause or with premature ovarian insufficiency, known as POI, with gut bacteria in people who had not reached menopause. POI means the ovaries stop working normally before the age of 40.

When the researchers combined the results, they found no consistent differences in the variety of gut bacteria or in two large groups of bacteria called Bacteroidetes and Firmicutes. The overall pattern was similar when they looked separately at people after menopause, people with POI and studies that used different testing methods.

However, the individual studies varied greatly. Diet, country, health conditions, medicines, probiotic use and laboratory methods may have affected the results. This makes it too early to say that menopause reliably causes one particular pattern of gut bacteria.

The combined findings do not show that a commercial gut test can diagnose symptoms or guide treatment. A single study or an animal experiment cannot establish that either.

What the research does not yet show

These were observational studies. This means the researchers recorded what they found rather than testing whether an intervention worked. The review did not test whether gut bacteria cause symptoms or whether commercial tests, foods, supplements or treatment changes improve symptoms.

NICE’s menopause guidance does not use gut microbiome or estrobolome tests to diagnose menopause or choose treatment. Based on the sources reviewed here, it would therefore be misleading to say that:

  • a particular pattern of gut bacteria causes hot flushes, brain fog, fatigue, bloating or other menopause symptoms;
  • a commercial gut microbiome or estrobolome test can diagnose the cause of those symptoms or select menopause treatment;
  • probiotics, fermented foods or soy supplements treat menopause symptoms by changing the estrobolome; or
  • hormone replacement therapy (HRT) should be started, changed or stopped because of a gut-test result.

Future research may explain more specific functions of gut microbes. At present, the studies differ too much to support these claims.

General digestive-health advice is different from menopause treatment

Eating a balanced diet and getting enough fibre can support general digestive health. Government guidance is for adults to get 30 g of fibre a day as part of a healthy, balanced diet. Fibre should come from a variety of foods, and drinking enough fluid matters too.

This is general health advice. It is not a treatment for menopause symptoms or a proven way to “balance” the estrobolome.

If constipation is the main problem

Constipation has many possible causes. These include low fibre or fluid intake, reduced activity, changes in routine, medicines, stress, anxiety or depression. Sometimes there is no obvious cause.

Speak to your GP if constipation is not improving with treatment, happens regularly, or comes with regular bloating, blood in your poo, unexplained weight loss, ongoing tiredness, a sudden change in bowel habits or tummy pain. Do not stop prescribed medicine without speaking to the person who prescribed it.

Bowel cancer screening is for eligible people who do not have symptoms. If you have new or worrying bowel symptoms, seek medical advice rather than waiting for a screening invitation.

Menopause symptoms still need individual assessment

NICE recommends looking at each person’s situation. Symptoms, medical history, risks, preferences and other possible causes should be considered together.

A claim about the gut microbiome or a commercial gut test should not replace that assessment. If symptoms are affecting daily life or you are worried about bowel symptoms, speak to an appropriate healthcare professional.

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