How a Balanced Microbiome Supports Healthy Thyroid Function

How a Balanced Microbiome Supports Healthy Thyroid Function

It is estimated that over 20 million Americans have thyroid disorders. With statistics showing that one in eight women will develop thyroid disease within their lifetime, making them 5-8 times more likely to develop thyroid conditions over men. 

Thyroid disease is usually a case of an under-active thyroid (hypothyroidism) or an overactive thyroid (hyperthyroidism) and can severely affect quality of life as every organ system in the body is affected by our thyroid hormones. Hypothyroidism is the most common and typically presents with constipation, stubborn weight gain, brittle hair, hair loss, dry skin and feeling unusually cold and/or fatigued. A poor functioning thyroid can also cause menstrual cycle, metabolism and mood disturbances. Left undiagnosed or without proper management, women are at risk for infertility, osteoporosis and cardiovascular disease. 

In the US, the most common cause of hypothyroidism is Hashimoto’s thyroiditis. This is an autoimmune condition where the thyroid gland is being attacked by antibodies. Eventually this causes destruction of the thyroid gland, resulting in an inability to make thyroid hormones. The role the microbiome plays in the development of autoimmune conditions, like Hashimoto’s has been a hot topic in recent research. And when we think about the fact that 70-80% of our immune system exists in our gut, it’s easy to see the connection here. 

The Autoimmune-Microbiome Connection 

The gut is responsible for digesting and absorbing all the nutrients we get from our food and is the main site where our immune system recognizes what is safe versus what is a threat. If our microbiome is out of balance, or dysbiotic, the whole system of checks and balances can get thrown off, making us more susceptible to autoimmune conditions. 

You’ve likely heard about a condition called leaky gut, aka intestinal permeability. This is where the cells that line the intestinal wall are no longer tightly held together and allow things to “leak” into circulation that should not otherwise be there. When our immune system recognizes these “non-self” intruders, it triggers an inflammatory immune response. Sometimes mistakes happen and “self-proteins” get tagged as foreign, creating an immune response to our own tissues. We now have great research demonstrating how leaky gut leads to autoimmune conditions, like Hashimoto’s, in this way. 

Another less common type of autoimmune thyroid disease is a Grave’s Disease. This can cause an overactive thyroid gland, or hyperthyroidism. A study looking at the difference between the gut microbiome of Grave’s patients versus healthy individuals found lowered microbial diversity in the Grave’s population. This research further demonstrates the connection between the microbiome and autoimmune thyroid disease. 

How to Support a Healthy Microbiome & Thyroid 

Let’s first talk about factors that disrupt the microbiome and contribute to thyroid dysfunction: 

• Antibiotics: We all know that antibiotics are not great for our gut. This is because they do not selectively wipe out bad bacteria, but rather wipe out both the good and the bad bugs. Appropriate use of antibiotics and avoidance when possible is a great way to keep a healthy balance of good flora. 
• Avoiding food triggers: Food triggers certainly vary by person, but a common food trigger for Hashimoto’s thyroiditis is gluten. It is estimated that over 20% of people with autoimmune conditions are triggered by gluten. The work of Dr. Alessio Fasano, MD has demonstrated how the consumption of gluten triggers the release of protein called  zonulin, which can loosen the tight junctions in our gut and contribute to the development of leaky gut and autoimmune disease. 
• And many more: Other factors that harm the gut microbiome are chronic stress, environmental toxins, poor sleep, birth control pills, and diets low in fiber and rich in processed foods and sugar. 

 Now let's review ways to support a healthy thyroid and microbiome:  

•  A healthy diet: The importance of diet and its effect on the microbiome cannot be underestimated. In fact, research shows that dietary shifts can impact the microbiome in just 24 hours! There is no one “right” diet for everyone, but in general, the Mediterranean Diet continues to be one of most well researched diets for health. The many benefits it provides are being rich in antioxidants, vegetables, omega-3 fatty acids, and fiber, and it is low in refined carbohydrates and sugar. 
•  Correcting nutritional deficiencies: Deficiencies in B vitamins, magnesium, selenium and iodine can all impair thyroid function. Studies show a reduction in thyroid antibodies with daily supplementation of 200 mcg of selenium. An easy dietary hack to obtain optimal levels of selenium for a happy thyroid is to eat 3 Brazil nuts each day. 
•  Prebiotics & Probiotics: Prebiotics are specific types of dietary fiber that act like fertilizer to the bacteria in the gut microbiome. A good prebiotic can selectively help the growth of beneficial bacteria, which in turn makes you healthier! Probiotics also help influence the gut microbiome by directly placing beneficial bacteria in the gut that can help crowd out the harmful bacteria. A clinical trial comparing two groups of adults with confirmed hypothyroidism found that after 8 weeks of supplementation with prebiotics and probiotics, thyroid labs improved and the dose of thyroid medication was lowered in the supplement group. 
•  Stress reduction: Reducing stress is another great way to support optimal thyroid function and a healthy microbiome. Not only is stress a risk factor for disrupting the microbiome and developing leaky gut, but when stressed, we are unable to properly digest our food and get the nutrients we need from our diet. Guided meditation, breathwork, and making healthier lifestyle choices have all been shown to have positive impacts on thyroid function. 

Autoimmune thyroid disease, like Hashimoto’s and Grave’s disease, are on the rise. The gut microbiome is a fascinating area of research uncovering an increasingly high correlation between autoimmune disease and thyroid dysfunction. Interventions beyond prescribing thyroid hormones should be implemented to address the root cause and gain maximal improvement in symptoms for those with thyroid disease. A comprehensive treatment plan that looks at optimizing the diversity of the gut microbiome and healing leaky gut should always be considered. 

Dr. Elizabeth Wade, ND

Naturopathic Doctor

Dr. Elizabeth specializes in reproductive health, infertility, environmental medicine, and autoimmune disease. She is committed to staying up to date in the world of microbiome research and sees her doing so as fundamental in her ability to get to the root cause of her patients’ health concerns. Dr. Elizabeth offers one-on-one health consultations at her private practice in Portland, OR to ensure everyone has access to the information needed to reverse or prevent disease in the most effective and least invasive ways possible.

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