The Gut-Hormone Connection
The health of your gut is so important for your overall health because it directly impacts almost every other system of your body, including your hormones. The relationship between the gut microbiome and hormonal health is complicated, but this post will cover one major connection that I see frequently in my practice.
But first, what is the gut microbiome?
Your gut microbiome is the collection of bacteria, fungi, archaea, and viruses (or as I like to say, all the"critters") that live throughout your digestive tract. Every single person's microbiome is unique, and it is also constantly changing in response to the environment you provide for it, including your diet, medications, supplements, exercise habits, and even stress levels.
Your microbiome is home to a bunch of different critters, some of which are really beneficial and even crucial to your health, and others that are less beneficial and potentially even dangerous. Certain microorganisms in your gut play a huge role in your body's metabolism of estrogen. These microorganisms are collectively referred to as the estrobolome. Many of these microbes produced an enzyme in your gut called beta-glucuronidase that is key to regulating estrogen levels in your body.
Let's back up and run through the steps of estrogen metabolism real quick: estrogen is produced by the ovaries, circulates in your bloodstream, and then needs to be detoxified by the liver and excreted. The main pathway for excreting estrogen is through the gut, meaning you have to have a bowel movement to eliminate it. By the time that estrogen makes it to the gut, it has been altered by the liver to become inactive and bound to something called glucuronic acid.
Alright, now back to the role of the gut microbiome here! Beta-glucuronidase breaks this bond between estrogen and glucuronic acid, which then makes it possible for your body to reabsorb estrogen before it is fully excreted. If you have lots of bacteria in your gut that make beta-glucuronidase, you will reabsorb more estrogen, allowing it to recirculate, and causing high estrogen symptoms like breast tenderness, menstrual cramps, heavy periods, PMS/PMDD, and even uterine fibroids. Additionally, if you aren't having a bowel movement daily, this gives your body more time to reabsorb this estrogen from your gut as well.
There’s so much you can do to support your gut microbiome, but it all starts with your food choices! Here are some of my favorite tips for a healthy gut and healthy hormones:
Eat the rainbow of different fruits and vegetables because your gut critters love variety in your diet (here's a great guide!)
Focus specifically on eating prebiotic foods to feed your healthy gut bacteria. These include under-ripe bananas, onions, leeks, garlic, asparagus, sunchokes, dandelion greens, oats, apples, and beans.
Minimize your intake of sugar, artificial sweeteners, and alcohol since these promote the growth of more inflammatory bacteria in your gut
Load up on lots of cruciferous vegetables to support estrogen metabolism. These include broccoli, cauliflower, cabbage, brussel sprouts, kale, and bok choy
Drink enough water daily to prevent constipation
The gut microbiome impacts so much about your health; your digestion, immune system, nervous system, and even hormones all are strongly influenced by the health of your gut. When your microbiome is thriving, your body can clear estrogen efficiently and keep your hormones in harmony. Focus on plant diversity, hydration, daily movement (yes, that includes your bowels!), and fiber-rich foods. These small daily habits help your gut critters do their best work!
References:
Baker, J. M., Al-Nakkash, L., & Herbst-Kralovetz, M. M. (2017). Estrogen-gut microbiome axis: Physiological and clinical implications. Maturitas, 103, 45–53. https://doi.org/10.1016/j.maturitas.2017.06.025
Ervin, S. M., Li, H., Lim, L., Roberts, L. R., Liang, X., Mani, S., & Redinbo, M. R. (2019). Gut microbial β-glucuronidases reactivate estrogens as components of the estrobolome that reactivate estrogens. The Journal of biological chemistry, 294(49), 18586–18599. https://doi.org/10.1074/jbc.RA119.010950
Heiman, M. L., & Greenway, F. L. (2016). A healthy gastrointestinal microbiome is dependent on dietary diversity. Molecular metabolism, 5(5), 317–320. https://doi.org/10.1016/j.molmet.2016.02.00