the Gut-Hormone Connection

Understanding the interplay between our gut and our hormones can be an important step in improving your wellbeing.

Your Gut Is a Hormone Factory

The gastrointestinal tract produces and regulates more than 20 different hormones that influence:

• Appetite and satiety (ghrelin, leptin)

• Blood sugar control

• Stress response (serotonin, which begins in the gut)

• Inflammation

In fact, around 90% of the body’s serotonin is produced in the gut. While you may be thinking that serotonin is a neurotransmitter, it also acts as a hormone in that it helps regulate digestion and triggers cellular activity.

Your hormones influence your microbiome

Cortisol (stress hormone)

Chronic stress increases cortisol levels, which can:

• Slow digestion

• Increase gut permeability ("leaky gut")

• Alter the microbiome

• Heighten inflammation

Estrogen and progesterone

These hormones affect gut movement and sensitivity. That’s why many women experience the following symptoms during their menstrual cycle, pregnancy and peri/menopause:

• Bloating

• Constipation

• Diarrhea

• Cramping

The Microbiome Helps Regulate Hormones

Your gut microbiome plays a crucial part in hormone metabolism.

A healthy microbiome helps:

• Break down and recycle estrogen through the estrobolome, a specific group of gut bacteria involved in estrogen regulation

• Reduce inflammation, which can otherwise disrupt progesterone and cortisol

When the microbiome becomes imbalanced (a state called dysbiosis), hormone imbalances often follow. Symptoms may include:

• PMS or worsened menstrual symptoms

• Hot flashes or irregular cycles

• Mood swings

• Weight shifts

• Fatigue

• Thyroid fluctuations

The bacteria in our gut, especially the bacteria that make up the estrobolome, have a huge impact on the the levels and types of estrogen circulating in the body. The estrobolome produce beta-glucuronidase, a key enzyme for determine the fate of estrogen in the body- whether it will be excreted or reabsorbed back into the blood stream.

Undestanding Estrogen and beta-glucuronidase

Beta-glucuronidase is an enzyme that we need for helping to break down estrogen and it determines whether the estrogen will be excreted or reabsorbed back into the bloodstream. We want to have this enzyme! But we also don't want too much of it. Women, especially during perimenopause, might notice symptoms of estrogen dominance and this is likely related to an imbalance in the microbiome where there are too many beta-glucuronidase-producing bacteria and too much estrogen is reabsorbed instead of excreted out of the body. Estrogen dominance is not about too much estrogen being produced, but rather, not enough of it leaving the body.

When estrogen is repeatedly reabsorbed, people may experience:

• Heavy or painful periods

• PMS or PMDD

• Breast tenderness or fibrocystic breasts

• Endometriosis or fibroids

• Migraines (especially cyclical)

• Mood swings or anxiety

• Weight gain around hips/thighs

• Worsening perimenopause symptoms

We want our bodies to be flushing out excess hormones and toxins and the best way to do this is to move the body, drink plenty of clean fluids, and eat lots of fibre. If you're already checking these boxes and you're still having issues associated with estrogen dominance, it could be that your microbiome is producing too much beta-glucuronidase and estrogen is recycled back into the bloodstream.

If you think you may have an issue with estrogen dominance, it would be best to have some understanding of why. Common reasons include:

• Gut dysbiosis (imbalanced gut bacteria)

• Antibiotic use

• Low fiber intake

• Constipation (estrogen sits longer in the gut)

• High alcohol intake

• Liver detoxification issues

• Chronic inflammation

• Exposure to environmental estrogens (xenoestrogens)

How to support the hormone-gut connection:

Eat fibre-rich foods

Fiber feeds beneficial bacteria and helps remove excess hormones (especially estrogen). Vegetables, beans, berries, whole grains, seeds

Add fermented foods (or a probiotic)

To support microbial diversity you can add some yogurt, kefir, kimchi, sauerkraut, miso to your diet.

Prioritize stress management

Stress plays a major role in how we experience the effects of fluctuating hormones. It also influences our cravings and how we digest food and store fat.

Avoid environmental toxins

Be aware of the toxins in your environment from food, cleaning supplies, plastic containers, furniture. Toxic chemicals are everywhere but taking steps to minimize them can be benefit your hormonal health.

Balance blood sugar

Having protein-rich meals with healthy fats and avoiding carb-heavy meals can make a big difference. Planning both meals and snacks and having them on hand can help you avoid turning to those foods that you love when cortisol is high.

Limit alcohol

Alcohol can disrupt the microbiome and lead to estrogen dominance and inflammation- it raises beta-glucuronidase.

Eat foods with glucaric acid

Citrus fruits, apples, and cruciferous vegetables like broccoli and cabbage contain glucaric acid, a compound can help ensure that estrogen is flushed out of the colon.

Support the liver

The liver is the first step in detoxifying excess estrogen so have plenty of leafy greens, bitter foods, cruciferous vegetables, onions, garlic, antioxidants and healthy fats.

The takeaway

Hormones and gut health are very interconnected. When your gut is functioning well, your hormones have a stable foundation—and when hormones are balanced, your gut operates more smoothly. Like any two-way feedback loop, when you support one system, you naturally support the other. If you’re experiencing digestive issues alongside mood changes, fatigue, or menstrual irregularities, it might be your body hinting that this gut–hormone connection needs attention.