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.
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.
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.