The Estrobolome: The influence of gut bacteria on estrogen levels

Dr. Julia Christensen, ND

As naturopathic physicians we take a thorough history and ask questions about the functioning of most body systems.  The reason we do this is because the function of one system can very much influence another. In my practice, many people book visits to work on hormone balancing and regulation.  Often times in these sessions, (and this can be a surprise to many), my education involves teaching about the importance of optimal gut and liver function as these two organ systems play a huge role in regulation, breakdown and proper elimination of hormones.

In this article I’d like to talk about the estrobolome, which is a collection of specific gut bacteria that aid in the break down of estrogens.  Estrogen plays a role in many facets of health including cardiovascular, skin, cognition, fertility, weight, mood, and bone health.  Lower amounts of estrogen in post-menopausal years are especially noticeable when women tend to experience a change in short term memory, increase in weight, and a higher risk for osteoporosis and cardiovascular disease.

In a broader sense, there is more and more research coming out linking the development of many conditions to an unhealthy gastrointestinal microbiome.  And specifically in relation to estrogen, there is an enzyme called beta glucuronidase in our gut, which can break down estrogen.  When this enzyme is active it causes the release of estrogen, making it freely available to re-circulate in our bodies and be active once again. When we have higher amounts of beta glucuronidase we can cause an increase in circulating estrogen, and vice versa with too little beta glucuronidase causing too little estrogen.  The implication of higher amounts of estrogen in the body is the potential for development of estrogen related conditions such as polycystic ovarian syndrome (PCOS), endometriosis, painful periods (dysmenorrhea), or estrogen related cancers. The opposite is also true in that not enough beta glucaronidase can lead to lower levels of estrogen in the body.  As mentioned earlier these can include: a higher risk for osteoporosis and cardiovascular disease, obesity, a decline in cognition, and mood changes such as anxiety and depression.

As with anything in the body we want to find a homeostasis or a sweet spot of balance in the body. The good news is that there are modifiable lifestyle factors that we can alter to control the levels of beta glucuronidase in your gut which can help to mitigate the levels of estrogen in your body. Things that negatively impact the body and cause an increase in the level of beta glucaronidase and therefore higher circulating estrogen levels include: alcohol, antibiotics, oral contraceptive pills, higher amounts of adipose tissue (ie fat cells), and high cholesterol (measured in the blood).  Ways that we can maintain a healthy gut microbiome and decrease the amount of beta glucuronidase include: eating fermented foods, lactobacillus probiotic strains (reuteri, gasseri, and acidophilus), and exercise.

In summary, get to know and be friendly with your microbes, as we now know the importance of ensuring adequate liver and gut function to support healthy estrogen levels.