When you have hypothyroidism it's easy to get caught up in thyroid lab values and which thyroid meds and supplements work the best. While these are significant factors in improving thyroid health, it's important to remember gut health is foundational to thyroid health. As long as you struggle with a leaky gut, gut inflammation, gut infections or parasites, heartburn, poor digestion, or chronic constipation or diarrhea - conditions that are so popular they fuel a multi-billion-dollar industry of drugstore remedies - you'll never experience optimum thyroid health.
As I mention in the introduction to my book, poor thyroid function is like the engine light in your car turning on - it's an indication to open the hood, investigate the engine, and repair what's wrong. You don't want to just take a drug or a supplement that will make the engine light go off.
The gut-thyroid connection can be a vicious circle as hypothyroidism causes poor digestive health, and poor digestive health may cause hypothyroidism. This is why it's so important to appropriately manage Hashimoto's and hypothyroidism, which involves more than finding the right thyroid medication. For the most part however, America's addiction to processed foods, sweets, and stressed-out lifestyles leaves most people in need of some serious gut repair.

How poor gut health impacts the thyroid

For 90 percent of Americans, hypothyroidism is caused by Hashimoto's, an autoimmune thyroid disease. Since most of the immune system is situated in the gastrointestinal (GI) tract, poor gut health is a significant factor in triggering and exacerbating autoimmune diseases such as Hashimoto's. An important step in taming Hashimoto's is to repair gut health.

Conversely, appropriately managing Hashimoto's and restoring thyroid function can help improve digestive function. Studies show both T4 and T3 protect the intestinal lining from ulcers. Studies also show hypothyroidism can cause intestinal permeability, or "leaky gut," which allows undigested food into the bloodstream and instigates an immune attack. These are examples of the thyroid-gut vicious cycle and how you may need to go after both fronts at once.

Gut flora and T3

Our digestive tracts host an array of bacteria that contribute to our health in a number of ways. One way is in the production of active thyroid hormones. A whopping 20 percent of thyroid function depends on a sufficient supply of healthy gut bacteria to convert T4 to T3. When diets are poor and digestion falters, dysbiosis, an overabundance of bad bacteria, crowds out the beneficial bacteria, thus hampering the production of active thyroid hormone. Studies have also shown that bacterial gut infections reduce thyroid hormone levels, dull thyroid hormone receptor sites, increase the amount of inactive T3, decrease TSH, and promote autoimmune thyroid disorders. Additionally, some studies have found connections between Yersinia enterocolitica and Hashimoto's disease - antibodies to this bacteria are 14 times higher in people with Hashimoto's. Maintaining healthy gut flora and addressing bacterial overgrowth is an important component of good thyroid function.

Low stomach acid

Hypothyroidism contributes to hypochlorhydria, a condition in which stomach acid is too low. For someone with acid reflux this may sound like a good thing, but in fact low stomach acid often causes heartburn. When hydrochloric acid is low the stomach cannot digest food thoroughly. The food in the stomach begins to rot and putrify. The small intestine attempts to reject this rotting mess, so the putrified food shoots back up into the esophagus. Though the food is not acidic enough for the small intestine, it is too acidic for the delicate tissue of the esophagus and causes painful heartburn. When this poorly digested food eventually does make its way into the digestive tract, it contributes to intestinal inflammation, infection, and leaky gut.

Although hypothyroidism can contribute to low stomach acid, low stomach acid can also contribute to hypothyroidism. It's estimated more than 90 percent of the population suffers from hypochlorhydria, due to nutrition-poor diets of processed foods. The digestive dysfunctions stemming from low stomach acid likewise set the stage for autoimmune disease, chronic stress, and poor absorption of nutrients, all of which can lead to hypothyroidism.

Poor gallbladder function

Many people don't realize how important the gallbladder is for proper digestion. It secretes bile to emulsify fats, which in turns aids in mineral absorption and prevents irritation of the GI tract. Hypothyroidism can cause the gallbladder to become sluggish and congested. A sluggish gallbladder increases the risk of gallstones; studies show more gallstones and bile duct stones among those with hypothyroidism.

A sluggish gallbladder also hinders the liver's ability to detoxify. Poor liver detoxification not only hinders the conversion of T4 to T3, but also prevents the elimination of excess estrogen. As a consequence excess estrogen leads to an over abundance of the thyroid-binding proteins that transport thyroid hormones through the bloodstream. Too many thyroid-binding thyroid hormones prevent thyroid hormones from getting into the cells and hypothyroid symptoms ensue.

Repairing the gut begins at the plate

The topic of repairing digestive health is discussed in my book, and is worthy of a book in itself. However a few key points are worth mentioning again:

Food intolerances

The Elimination/Provocation Diet requires you eliminate gluten, dairy, eggs, soy, corn, and yeast for two to three weeks, and then reintroduce each food every 72 hours to monitor reactions. It's imperative to eliminate problem foods to support gut health. And of course if you have Hashimoto's you should be on a strict gluten-free diet anyway, as the book explains.

The 4-R program

In the book I go over the basics of restoring gut integrity, which is known as the 4-R program. The remove phase removes harmful foods from your diet and eradicates bacterial and/or parasitic infections. The reinoculate phase restores healthy gut flora, necessary for T3 conversions, with probiotics. The replace phase includes support for hydrochloric acid, digestive enzymes, and gallbladder function until your GI tract is up and running on its own again. Lastly, the repair phase includes the use of specific herbs and nutrients to reduce gastric inflammation and regenerate the intestinal walls.

Manage stress and blood sugar swings

Chronic stressors lead to either too much or too little of the stress hormone cortisol. Studies show both extremes weaken the integrity of the GI tract. Blood sugar imbalances from diabetes, insulin resistance, or hypoglycemia are the most common chronic stressors today, and contribute to poor GI and thyroid health.

Address small intestinal bacterial overgrowth

Although dysbiosis in the large intestine has been the target of attention for some time, newer research is showing the importance of addressing dysbiosis in the small intestine. I find a monosaccharide diet to be quite effective in managing this issue. As I mentioned in last month's article, this is a diet akin to the GAPS diet that eliminates all grains, starchy vegetables (such as potatoes), and sweeteners except for honey. It also includes daily consumption of homemade bone broths, which are soothing to the gastric lining. For people who find a gluten-free diet isn't delivering the expected benefits, a monosaccharide diet may be the next step.

Don't remove the engine light

The topic of restoring digestive health is vast and formidable, and this overview in no way constitutes a comprehensive approach. Instead it is an introduction to some fundamentals of thyroid health that go beyond thyroid meds and supplements. As I mention in the introduction to my book, poor thyroid function is like the engine light in your car turning on - it's an indication to open the hood, investigate the engine, and repair what's wrong. You don't want to just take a drug or a supplement that will make the engine light go off.

Given the deleterious combination of poor diets, blood sugar imbalances, and the chronically stressful lives so prevalent today, the gut is usually the first to complain. Don't ignore what it has to say with the use of over-the-counter medicines. When it goes down other systems in the body quickly follow suit, including the thyroid (the brain is also severely impacted, which will be the topic of my next book). When you set about recovering your thyroid health, it's imperative you address digestive health as well.