The Gut Microbiome and the Estrobolome: How gut microbes affect estrogen metabolism

Can your gut microbiome affect your hormones?

It’s All Connected!

In a systems biology approach, like every other body system structure and functioning, liver health, kidney health, gut health, and hormone health are connected.

The gut microbiome secretes bioactive metabolites: reactivated estrogens, short chain fatty acids, amino acid metabolites, and secondary bile acids that modulate estrogen levels.

Estrogen Production, Conjugation, and Excretion

Estrogens are primarily produced in the ovaries, adrenal glands, and fat cells and circulate in the bloodstream (both in free and bound form) before undergoing metabolism and conjugation in the liver.

Conjugated estrogens are eliminated from the body after being converted to water- soluble molecules (during Phase 2 liver detoxification).

Those molecules that contain conjugated estrogens are then excreted in urine (assuming the liver and kidneys are functioning optimally) or in bile in the feces (assuming optimal intestinal health).

estrobolome diagram
Image from Kwa, M.J., Plottel, C.S., Blaser, M.J., & Adams, S. (2016). The Intestinal Microbiome and Estrogen Receptor-Positive Female Breast Cancer. Journal of the National Cancer Institute, 108 8.

Microbial Deconjugation of Estrogens

The conjugated estrogens excreted in bile can be deconjugated by bacterial species in the gut that have beta-glucuronidase and beta-glucosidase activity.

Deconjugation is a reaction in which the estrogens become unbound, which leads to estrogen reabsorption into circulation from the gut (enterohepatic circulation of estrogens), which can be the underlying cause of excess estrogen in the body.

Beta-glucuronidase activity is increased by the Clostridia, Ruminococcacea, Eschericia and Shigella families of bacteria, which can be over-expressed during dysbiosis (imbalanced gut bacteria).

To date, over 60 bacterial genera and species colonizing the human intestinal tract have been identified that contain genes that encode beta-glucuronidase and beta-glucosidase (the Vibrant Gut Zoomer 3.0 measures all 60 of these species).

Balancing the circulation of estrogens between the gut and the liver (enterohepatic circulation) by optimizing gut health can have a significant impact on hormone health.

Dysbiosis is Commonplace!

Now, that’s a lot of assumptions about optimal health and functioning when, sadly, it’s known that gut dysfunction and imbalance in the gut microbiome are common.

The composition of the microbiome and the estrobolome can be impacted by host factors such as

  • age
  • ethnicity
  • genetics
  • adiposity/obesity (approximately 2/3rd of Americans are overweight or obese)
  • lifetime exposure (the exposome)
  • environmental influences such as:
    • diet
    • alcohol
    • antibiotics
    • xenobiotics
    • pollutants

All of these factors exert selective pressure on gut microbiota that modulate estrogen levels. That means they can make it easier for the wrong bacteria to flourish and harder for the right bacteria to thrive.

Estrogen-like compounds may negatively impact the growth and survival of certain species of bacteria.

Thus, the gut microbiome-estrobolome relationship is a relationship where cross-talk between microbiota and hormones may provide protection from disease or alternatively, increase disease risk.

Bottom line: gut health improves or worsens hormone health.

Gut Permeability and Gut Motility

Intestinal epithelial cells possess the ability to metabolize sex hormones, notably estrogen. Estrogen and estrogen receptor signaling play a role in maintaining what you may have heard called ‘leaky gut syndrome’ : intestinal epithelial barrier function, tight junction expression and permeability, and gastrointestinal motility.

Gut Inflammation and Oxidation

Additionally, other estrogen-like metabolites can also be produced by normal reactions in the gut and lead to synthesis of estrogen-inducible growth factors, which might have carcinogenic (cancer-causing) potential. Therefore, decreasing intestinal inflammation and oxidative stress is critical to gut microbiome and estrobolome health.

Gut Microbial Diversity

A relationship has also been found between gut microbial richness, as measured by the Shannon Index, systemic and fecal estrogens, and beta-glucuronidase activity in healthy postmenopausal women and men.

To sum it up, use the Vibrant Gut Zoomer 3.0 to assess microbiome-estrobolome health, and focus on these 8 strategies!

Healthy Microbiome Estrobolome Axis Image.png

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