What does the transition or menopause do to your gut microbiome?
Menopause changes the composition of your gut microbiome, particularly at the level of specific bacterial species and in the way your gut processes oestrogen. Whether it causes symptoms and what you can do about it yourself is still actively being researched.
During menopause, oestrogen levels fall, and this affects the composition of your gut bacteria. At the level of the major bacterial families, the changes are small: an analysis of three studies found no measurable differences in the ratio of the large main groups. At the level of specific bacterial groups, however, shifts are visible. Certain species such as Odoribacter and Bilophila increase, while Akkermansia muciniphila (a bacterium that protects the gut wall) decreases. Whether these shifts actually cause harm is still unclear.
One of the clearest effects occurs in what is known as the estrobolome: the part of your gut microbiome that processes oestrogen and partially returns it to the bloodstream. After menopause, this system is less active, meaning your body absorbs even less oestrogen than it already produces. This can become a self-reinforcing cycle: lower oestrogen leads to an altered gut microbiome, and that altered gut microbiome in turn amplifies the decline in oestrogen.
Whether overall gut microbiome diversity also declines is not clear-cut. A large study of more than 2,000 Hispanic women saw a trend in that direction, but two other studies found no significant difference. Two separate studies also found an association with less favourable blood sugar levels and fat metabolism, but these are associations observed in people, not demonstrated cause-and-effect relationships. Animal research furthermore shows that the absence of female sex hormones leads to a more permeable gut wall and greater inflammation, although this effect has not yet been confirmed in humans.
Probiotics and prebiotics are being investigated as possible forms of support, but the evidence for this is too limited for concrete recommendations. There are preliminary indications of beneficial effects on bone health and cardiometabolic risk factors, but the studies are small and the mechanisms are not yet well understood.
This answer is based on a systematic analysis of three small studies combined (156 participants), a large population study of more than 2,000 Hispanic women, animal research using ovariectomised mice, and multiple review articles. The evidence is predominantly observational: it reveals associations, but cannot yet demonstrate cause and effect in humans. In particular, the findings on gut permeability and the estrobolome come largely from animal or mechanistic research.
Does my gut microbiome change as I get older, and does it matter?
Your gut microbiome certainly changes as you get older, but whether that is harmful depends strongly on which direction that change goes. What you eat has a major influence on this, so that is a concrete area to pay attention to.
What are the signs that your gut flora is out of balance?
There are several recognisable signals, of which abdominal complaints such as persistent pain, diarrhoea, or constipation are the best supported. If you experience prolonged bowel complaints after a course of antibiotics or an infection, discuss this with your GP.
What does alcohol do to your gut microbiome?
Chronic heavy drinking demonstrably disrupts the gut microbiome, with consequences for the heart and liver. Moderate drinking was not examined in these studies, but the mechanisms identified provide a clear picture of how harm arises.
Can your gut microbiome influence inflammation in your body?
Your gut microbiome can influence inflammatory processes throughout your body via the gut wall. Eating more fibre and exercising regularly are the most well-supported ways to influence this favourably.
Does my weight and metabolism change during menopause?
During menopause, your body composition changes profoundly: more abdominal fat, less muscle and a lower resting metabolic rate. Exercise and nutrition demonstrably help, and discuss hormone therapy with your doctor as an additional option.
Is my gut flora linked to being overweight?
Your gut microbiome is probably linked to excess weight through multiple mechanisms, but a proven causal relationship in humans is still lacking. A varied diet that supports your gut microbiome is worthwhile, but specific supplements for weight loss have not yet been proven effective.