The Gut-Hormone Connecion

Recent studies reveal that your gut microbiota regulate and impact nearly every hormone in your body, including thyroid hormones, estrogen, melatonin and stress hormones.

From a female perspective, this clinical research has been so needed by millions of women who have been suffering with digestion and female hormonal imbalances. Finally, the ancestral wisdom of “food as medicine” is coming to light in a clinical format.

We now have the studies to show the connection and confirmation that it is absolutely necessary to change our food and lifestyle in order to create a balanced gut microbiota. The gut is the fundamental starting point for treating and preventing many chronic diseases.

Let’s focus on the gut-hormone connection.

Your gut and brain send signals and communicate to each other through the vagus nerve. This communication pathway is called the gut-brain axis, regulated by neurotransmitters, various hormones, immune system cell signals, and different organisms. In general, this axis regulates gastric and intestinal function and energy balancing. It works as a ‘bi-directional feedback loop’. Let’s look at 4 hormones:

Thyroid:

• The thyroid hormone Free T3, also known as the active form of T3, is what makes your thyroid increase your energy, manage your weight, regulate your menstrual cycle, control heart, muscle and digestive function, brain development, regulates lipid metabolism, and bone maintenance. Let’s just focus on digestive function.

• Conversion is essential: 20% of the conversion from inactive T4, into the active form T3, happens in your gut! The remaining conversion happens in your liver, kidneys and thyroid. But 20% is still significant.

• 80% of your immune system is in your gut! For those with bloating, gas, leaky gut syndrome, Inflammatory Bowel Disease, Small Intestinal Bacterial Overgrowth (SIBO), or other forms of gut imbalance (dysbiosis), this causes chronic low-grade and systemic inflammatory response by your immune system. This inflammatory response impairs the brain-gut signalling, and lowers TSH output from the brain, causing low T4 output by your thyroid. The less thyroid hormone your body produces, the less energy every single cell in your body receives.

• Low levels of circulating thyroid hormone can also cause impaired gut motility and constipation, which can perpetuate the cycle of hormone imbalance.

• Cortisol and T3 work together. Inflammation in the gut triggers the release of cortisol, a hormone produced by the adrenal glands, and is the body’s natural response to stress, inflammation, and injury.

• However, ongoing stress/cortisol release decreases active T3 levels while increasing levels of inactive T3, which can lead to thyroid dysfunction, as well as adrenal fatigue (low cortisol).

• You can also experience low cortisol levels which occurs after you’ve been living in over-drive for a long time and constantly releasing cortisol. Your hypothalamus-pituitary-adrenal axis is one area that is disrupted, and your adrenals say, “Hey, I can’t keep up making cortisol. Give me some more hormones to work with.” Progesterone, the pre-cursor to cortisol, now has to increase her contribution to fill the cortisol gap, which now disrupts the estrogen/progesterone balance. Everything is connected!

There are other possible variations why you may have a thyroid imbalance. Low gastric acid called hypochlorhydria, infections, food intolerances (especially gluten), stress, and other factors may play significant roles.

Anyone reading this who has thyroid and hormone imbalances, I urge you to discuss ordering a Thyroid Panel test, or a Complete Dutch test with your health care provider, or order online without a doctor’s referral. Unfortunately, thyroid imbalance and sub-clinical hypothyroidism is commonly overlooked.

Estrogen:

• One specific gut microbe, called estrobolome produce an enzyme, beta-glucoronidase, that converts female estrogens into its active form. 

• Estrobolome plays a crucial role metabolizing circulating estrogen levels.

• However, when gut dysbiosis is present, estrogen can be reabsorbed into the bloodstream causing estrogen dominance. This can lead to a wide range of health issues: including obesity, metabolic syndrome, cancer, endometriosis, endometrial hyperplasia, PCOS, cardiovascular disease, osteoporosis, fertility, and cognitive dysfunction. 

• Excess estrogen also increases levels of thyroid-binding globulin (TBG). When the gut microbiome is healthy, the estrobolome produces just the right amount of beta-glucuronidase to maintain estrogen homeostasis.

• However, when gut dysbiosis is present, beta-glucuronidase activity may be altered. This produces either a deficiency or an excess of free estrogen, thus promoting the development of estrogen-related pathologies.

• Probiotic supplementation has shown to regulate the estrobolome and reverse estrogen-related pathologies. Specifically, Lactobacillus variations have been successful. Current research is focussing on matching certain strains with specific health conditions.

Melatonin:

• Melatonin is a hormone that is best known as the “sleep” hormone, regulating sleep-wake cycles. However, it also has an important role regulating both inflammation and motility in the gastrointestinal tract.

• To make melatonin, your body needs serotonin, a neurotransmitter hormone. Serotonin is known as the “happy” neurotransmitter, however in relation to gut function, it also regulates appetite, eating, and digestion.
• 90% of serotonin is made in your gut. Consequently, if you don’t have the specific microbes and the right amounts present in your gut, such as spore-forming microbes, you won’t produce enough serotonin, thus unable to produce melatonin.

Stress/PTSD:

• Ongoing release of cortisol, epinephrine, and norepinephrine hormones put your body on high alert.

• This causes damage to gene expression in some gut microbes, causing increased susceptibility to infection and increased damaging effects, including inflammation of intestinal walls and damage to “good” bacteria living in the gut.

But what if you’re one of those people who eat what many define as a “well balanced” diet of raw veggies and fruit, possibly minimal red meat, gluten-free grains, and avoiding foods that are processed, or that contain trans fats and refined sugars?

In general, this diet may sound ideal, and may be extremely important to maintaining a healthy microbiome, however it goes beyond that. If you’re experiencing gut or hormone imbalance symptoms, this is your body’s way of saying, or screaming: “Listen up, I’m here to help balance you. Something is not balanced. Please fix it.”

The main areas that most commonly need balancing, along with Thyroid support include: (assuming you’ve seen your GP to rule out other conditions)

• Blood sugar balancing

• Adrenal support (hypothalamic-pituitary-adrenal axis)

• Gut support

• Detoxification of liver and gallbladder (and in some cases kidney)

• Essential Fatty Acid (EFA) balance

Author: Marla Samuel, MSc, RNCP, DipHom

What else damages and imbalances ‘good’ gut bacteria ?