The Thyroid-Gut Connection
Chances are, if you are suffering with metabolic challenges such as difficulty losing weigh, low energy, brain fog, constipation or body aches and pain, then you’ve had your thyroid hormones tested. If you haven’t, then you definitely should. However, checking thyroid hormone levels alone doesn’t tell you the whole story.
There are two common scenarios that lead to these thyroid related symptoms. The first is Hashimoto’s disease, an autoimmune condition that accounts for 90% of all cases hypothyroidism. In this case, your thyroid hormones will likely be outside the normal range when tested. The second is a pattern called thyroid hormone resistance, where thyroid markers on a blood panel (THS) look completely normal, yet you still have all the signs and symptoms of hypothyroid.
Both scenarios are very common and both have a strong connection to the health of your gut.
My guess is that your doctor hasn’t mentioned a thing about your gut at all…let alone the gut-thyroid connection. And why would they? Since, in the conventional medicine model, the endocrinologist treats your thyroid, while the gastroenterologist treats your gut.
The truth is, there is a strong connection between your thyroid and gut, and both must be addressed if you want to restore your health and vitality.
Gut Autoimmune Connection
As mentioned above, Hashimoto’s Disease (Autoimmune Hypothyroid) is by far the most common cause of hypothyroid in the US. The villain in this story is not the thyroid gland, but instead, a misbehaving immune system. Autoimmune conditions occur when one’s immune system becomes triggered and overzealous, causing the immune system to misidentify the body’s healthy tissue as a foreign invader. In the case of Hashimoto’s, this case of mistaken identity results in the immune system attacking and destroying the thyroid gland, eventually leading to hypothyroidism.
Do you know where the majority of your immune system is located? You guest it, your gut!
Between 70-80% or your immune system is located in your gut. This tissue, know as gut associated lymphoid tissue (GALT), provides a critical immune barrier between the contents of your gut and the delicate environment in your cells and bloodstream. When this barrier breaks down or becomes threatened, the GALT initiates an all out attack. Antibodies search for and tag the foreign invaders for destruction. If the threat become too overwhelming, the immune system can lose specificity and may tag and destroy any protein, including healthy tissue.
This phenomenon is call loss of immune tolerance, and it must be resolved to calm down the autoimmune thyroid storm.
The GALT can become triggered by multiple factors including stress, infectious agents, food particles, toxic compounds, medications and more.
Potential Causes of GUT Immune Barrier Breakdown
- Overuse of Antibiotics. Antibiotics disrupt the bacterial environment in your gut known as the microbiome. Normal healthy bacteria are suppressed leaving room for harmful organisms to take over. A single round of antibiotics can disrupt the gut immune barrier for 6-12 months.
- NSAID’s. Chronic use of NSAIDs (non-steroidal anti-inflammatory drugs) like ibuprofen and aspirin can cause damage to the intestinal lining resulting in breakdown of the gut immune barrier.
- Birth Control Pill. Birth control medications are commonly prescribed to treat many different conditions besides their typical use as a contraceptive. These include acne, menstrual irregularities, menopausal symptoms and mood disorders. The pill is known to increase the likelihood of SIBO and SIFO (small intestine bacterial or fungal overgrowth), both of which cause major damage to the gut immune barrier.
- Diets High in Refined Sugars and Grains. Refined sugars and grains wreck havoc on your gut’s immune barrier. Over consumption will lead to pathogenic overgrowth of bacteria, yeast and other dangerous microorganisms that threaten your gut’s immune barrier.
- Chronic Stress. It’s well documented that excess stress over time will lead to profound changes in your microbiome and significant weakening of all your immune barriers.
You may be thinking “But I don’t have any gut problems” because you may not have the typical gut symptoms. It’s possible, even common, to have food sensitivities, dysbiosis, immune barrier breakdown and even Celiac disease with any gut symptoms at all. In fact, over 50% of individuals diagnosed with Celiac disease do not complain of gut symptoms. Clues that you may have an underlying gut problem without the typical gut symptoms include skin rashes, mood swings, poor concentration, acne, PMS, headaches, sinus congestion, vertigo or fatigue.
For many of my patients, the first sign of a potential digestive problem is actually being diagnosed with an autoimmune condition.
But beyond autoimmunity, your gut also supports your thyroid health in other ways.
Your Gut and Thyroid Hormone Conversion
There are two thyroid hormones produced by your thyroid gland, T4 and T3. The majority of what your thyroid puts out (90%) is T4 and only a small fraction is T3. The problem here is that T4 is actually an inactive form of thyroid hormone that must to be converted into active T3 to have any effect in your body. This conversion from inactive T4 to active T3 takes place in tissues outside the thyroid gland. Over 20% of this conversion is made by friendly bacteria in your gut. If you have an overgrowth of unfriendly organisms, you may not be making all the active T3 your body requires.
This can lead to low thyroid symptoms even though your thyroid is working just fine.
Your Gut and Thyroid Hormone Resistance
Hormone resistance occurs when there are adequate levels of hormones in your body but your cells are not able to use them. You have likely heard the term “insulin resistance”. This occurs when insulin receptors found in the membranes of all cells become desensitized to insulin. When this occurs, there is plenty of insulin available but the cells are unable to use it. The same thing can, and often does, happen with thyroid hormone. When your cells are resistant to thyroid hormone, no amount of that hormone will help. This is why many of my patients will still complain of thyroid symptoms even though they are already taking thyroid hormones. Also this is why your labs can appear completely normal, yet you can still suffer with all the thyroid symptoms. The number one cause of thyroid hormone resistance is inflammation coming from the gut.
Improving gut health and eliminating the inflammation is the only way to improve the health of your thyroid.
Heal Your Gut
It’s imperative to heal your gut if want to regain your energy, get rid of brain fog, loss the stubborn weight, end the nagging aches and pains, and start feel like yourself again. Your thyroid health is depending on it. I recommend working with a functional medicine practitioner that understands the connections between your gut and your health, and who has the expertise to create a personalized treatment plan based on your specific needs.
