Estrobolome: The gut-estrogen connection
Intro
The estrobolome is the term for how the gut microbiome interacts with and affects levels of estrogen. The gut microbiome is the term for all of the bacteria and other microbes in the gut. The “gut” is usually defined as the whole gastrointestinal tract, going from mouth to anus. So, the “gut” involves the mouth, the esophagus, the stomach, the liver, the pancreas, the gallbladder, the small intestine, and the large intestine.
Most of the bacteria in the gut can be found in the large intestine, but bacteria can also be found in the small intestine (such as the duodenum, jejunum, and ileum). In this blog post, you will learn how the gut microbiome can play a role in relative estrogen dominance.
Estrogen in the gut
Estrogen can end up in the gut and can interact with the gut microbiome after estrogen gets processed, metabolized, and detoxified in the liver. After going through several transformations, estrogen can go from the liver to the gallbladder and then into the small intestine via bile. Bile is a liquid that contains digestive enzymes and “toxins” that have been metabolized. Before it ends up in bile, estrogen is turned into a glucuronidated conjugate that makes the detoxified estrogen ready for elimination out of the body via fecal matter (aka poop).
Glucuronidated estrogens can be un-glucuronidated in the gut, which reactivates them. Reversal of glucuronidation is completed via a gut bacteria-produced enzyme called beta-glucuronidase. There are specific types of bacteria that produce this enzyme, and there are several factors that can determine the population size of this bacteria and therefore affect the amount of beta-glucuronidase in the gut.
It should also be noted that estrogen metabolism can happen in other organs too, such as the kidneys. But, we’ll speak about estrogen detoxification in more-detail in another post.
Gut Bacteria + Estrogen
There are several bacteria that produce beta-glucuronidase, and depending on their population sizes, more estrogen metabolites could get reactivated. The level of bacteria responsible for the production of beta-glucuronidase can be tested for via functional stool testing. And, certain functional labs can also test for levels of beta-glucuronidase in the gut. The specific bacteria that make beta-glucuronidase are:
Collinsella, Bacteriodes, Bifidobacterium Citrobacter, Escherichia, Faecalibacterium, Lactobacillus, Proprionobacterium, and more.
After glucuronidated estrogen metabolites are reactivated by beta-glucuronidase, these reactivated estrogen metabolites can be reabsorbed through the intestines, end up in the blood, and act on estrogen receptors in the body. And, researchers hypothesize that the estrobolome could play a role in the development of unopposed estrogens, such as breast cancer.
Diet & The Estrobolome
The population of the gut microbiome & levels of beta-glucuronidase can change depending on one’s diet. Science shows that a diet that is high in fat or protein led to higher levels of beta-glucuronidase. And, science also shows that those who regularly consumed fiber led to lower levels of beta-glucuronidase. In a small study with 20 premenopausal females that compared levels of estrogens in stool and in blood in those who had a standard American diet with high fat content and low fiber and those who had a vegetarian diet with high fiber and moderate fat content, it was seen that vegetarians had higher amounts of estrogens in stool and lower levels of estrogens in blood.
Summary & Takeaways
In this second part of my 4-part blog series on relative estrogen dominance, you learned all about the estrobolome. And, gut health and the gut microbiome are important factors to consider when one is undergoing hormone balancing treatment, especially for relative estrogen dominance.
As what you learned in this post today, certain strains of bacteria in the gut microbiome can reactivate glucuronidated estrogen metabolites, which are then reabsorbed into the blood - instead of being eliminated out of the body. And, the way estrogen is reactivated is through beta-glucuronidase.
Diet can also play a role in all of this! What science shows is that diets that are high in fat or protein leads to higher levels of beta-glucuronidase in the gut and that diets that are higher in fiber led to lower levels of beta-glucuronidase in the gut. So, looking at diet is going to be a big component when balancing the gut microbiome.
Next week will be the third part of this 4-part series on relative estrogen dominance, and I will be speaking about how estrogen is detoxified in the liver. So, make sure to sign up for my email list to stay up-to-date with future blog posts and more! And, if you want to schedule an appointment with me, click here.