More than 2,000 years ago an ancient Greek physician named Hippocrates once said, "All disease begins in the gut". However, it is only today that health experts have completely understood what Hippocrates said so long ago. Many studies have been done which further prove the link between an individual's thyroid gland and gut health.
The Gut and Its Important Functions
The "gut" refers to the hollow tube that passes from an individual's mouth to the anus. This way, anything that is being ingested in the mouth that cannot be digested will be excreted through the other end of the gut. This is a most basic yet most important role of the gut – to prevent any foreign objects or substances from entering inside a person's body.
A second critical role is to host 70% of the immune tissue inside the body. This is the part of the immune system that is collectively called GALT (Gut-Associated Lymphoid Tissue). The GALT is comprised of different types of lymphoid tissues that are capable of storing immune cells such as the T & B lymphocytes. These are the kinds of lymphocytes that defend the body by producing antibodies that fight against antigens which are identified by the immune system as disease-causing.
How Leaky Gut Syndrome Can Lead to Autoimmune Diseases
A problem occurs when one of these protective functions of a person's gut is being compromised. For example, when an individual suffers from leaky gut syndrome whereby the intestinal barrier becomes permeable, then it also becomes easier for large protein molecules to enter into the bloodstream.
Unfortunately, these large protein molecules should not be outside of the gut and if they are, the person's immune system will immediately tag it for destruction. These attacks made by the immune system, in an effort to protect the body against diseases-causing microorganisms, may also lead to the development of autoimmune diseases and one of these is Hashimoto's Disease.
Thyroid Hormones Help Protect the Gut
The tight junctions inside your stomach and your small intestines are also being strongly influenced by your thyroid hormones. The thyroid hormones T3 and T4 play a crucial role in protecting the mucosal lining of the gut from stress induced ulcer formation.
Studies reveal that people with gastric ulcers were found to have low levels of T3 and T4 hormones while their reverse T3 hormones were also in abnormal levels.
The Gut Bacteria Is Beneficial for Converting Thyroid Hormones
The gut bacteria are also very helpful in the process of converting inactive T4 hormones into an active form known as T3 thyroid hormones. About 20% of our T4 is being converted into an active form T3 inside the gastrointestinal tract with the help of an enzyme known as intestinal sulfatase. This intestinal sulfatase is produced from healthy gut bacteria.
If there is an imbalance between the amount of beneficial bacteria in the gut and the amount of pathogens, which is a condition referred to as intestinal dysbiosis, the proper conversion of thyroid hormones will also be reduced. As a result, most people who have poor gut health also suffer from the symptoms of thyroid problems.