Why Your GUT is important for Thyroid Function

If you have read any of my earlier blogs, you will know that I am a huge promoter of trying to dig to the deeper level of thyroid imbalances. While TSH is the main hormone that is tested, it doesn’t always explain the whole picture. Many times thyroid health depends on a complex interplay between the active thyroid hormone T3, reverse T3, inflammation, stress and sex hormones.  


For proper thyroid function to happen, the T4 in your body has to be converted into its active form T3.  This process is partially done in the digestive tract! The GI tract needs to have plenty of healthy colonies of bacteria in order for this process to happen. An imbalance of good to bad bacteria in the gut, otherwise known as dysbiosis can lead to low thyroid function.   This is the explanation why so many thyroid patients will have normal blood work, but feel like they still have all of the symptoms of an imbalanced thyroid.


If we take a look at thyroid symptoms, it is interesting that hypothyroid patients will get constipated while hyperthyroid patients tend to have diarrhea. These digestive symptoms are partially related to faulty metabolism but are also created by faulty digestion. Meaning that gut and thyroid dysfunction tend to go hand in hand.


Hypothyroidism can also reduce the production of HCL or stomach acid, by reducing a hormone called gastrin. When there is low gastrin and consequently low HCL produced people will feel bloated, have reflux and indigestion.  Long term, low HCL will also tend to cause an imbalance of good and bad bacteria in the gut, which further will compromise thyroid function.


How do you know if you have dysbiosis?


If you experience any of the following symptoms, you should be checked for dysbiosis

  • Bloating, cramping and abdominal pain
  • Constipation or diarrhea
  • IBS
  • Indigestion, heartburn
  • Fatigue or brain fog
  • Unexplained weight gain, or difficult weight loss
  • Joint pain or skin conditions


Conditions that can cause/contribute to dysbiosis

  • High sugar or refined carb diet
  • Low fibre diet
  • History of antibiotic use
  • History of NSAID or Proton Pump Inhibitor Use
  • Stress
  • Gastrointestinal Infections
  • C-section delivery, or never being breastfed


A good digestive system is an essential part of overall vibrant health. If you suffer with any of the above symptoms it is important to optimize that digestive function especially when dealing with an autoimmune or thyroid disorder.


  1. Tammie White March 6, 2018 at 10:27 am #

    How do I get better gut health.
    I have a history of antibiotics though not so much now.
    I had 2 C Sections
    I was not breast fed…….


    • Robin Walsh March 6, 2018 at 1:37 pm #

      Hi Tammie!
      reducing sugar and refined carbohydrates
      reducing stress 🙂
      eating lots of fibre and lots of variety of vegetables
      taking a probiotic or eating fermented foods are all helpful ways of rebalancing and helping your gut function


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