Gut Microbiome-Thyroid: the missing link for gut healing?


For many of us, the goal of improving gut bacteria and healing leaky gut is a moving target. Taking probiotics is supposed to help, but of course for many people it seems not to help. There are even research studies indicating probiotics don’t work! Those studies look at whether the probiotic bacteria are present in stool samples weeks after discontinuing the probiotic, so they are testing whether the new organisms have colonized the gut successfully. There’s a point of logic those studies are missing, however: if the organisms weren’t present in the gut before, and nothing else changed, it isn’t logical to expect that the bacteria will colonize. There had to be a reason they weren’t there to start with, right? and those reasons can be: poor diet, high stress levels/altered HPA axis, pharmaceutical/recreational/occupational exposure to chemicals, too many harmful bacteria (ie the enemies of the probiotic bacteria), poor stomach acidity, high inflammation levels, and….poor thyroid function! In case you were wondering, no, those factors are never controlled for in the research studies that I’ve read.

Yes, the thyroid affects the gut, and as is typical the gut also affects the thyroid. Shall we call it a gut-thyroid axis? This would certainly be fitting. What we know is that several factors entwine the function of both:

  1. Gut bacteria affect/control immune function, and altered gut bacteria can cause autoimmune thyroiditis which lowers your thyroid hormone levels
  2. Imbalanced gut bacteria can also cause inflammation, which interferes with thyroid function
  3. The thyroid produces T4, which is changed into the more active T3 via an enzyme, which the gut bacteria produce
  4. Gut bacteria require selenium, as does the thyroid. Altered gut bacteria results in more usage of selenium, robbing the thyroid of it
  5. Thyroid hormone production requires iodine, and gut bacteria are primarily responsible for the absorption of this nutrient from ingested foods
  6. Poor thyroid function results in loss of gut microvilli, reduced absorption, and dysbiotic gut bacteria
  7. Imbalanced gut bacteria reduce the recycling (deconjugation) of thyroid hormone, effectively reducing the body’s storage of thyroid hormone
  8. TRH, Thyrotropin Releasing Hormone, is produced from the hypothalamus, which is affected by the gut bacteria as part of the HPA (hypothalamus pituitary adrenal) axis. This affects production of TSH, Thyroid Stimulating hormone, which causes release of thyroid hormone from the thyroid. Thus, gut bacteria affect release of thyroid hormone

There are other connections, but the point is that gut bacteria and thyroid are mutually dependent for function. Loss of function of one results in loss of function of the other. The most logical next thought is to consider what the symptoms of low thyroid are:

  1. Fatigue
  2. Muscle cramps
  3. Cold sensitivity
  4. Constipation
  5. Dry skin
  6. Weight gain
  7. Puffy face
  8. Muscle weakness
  9. Muscle aches and pains
  10. heavier or irregular menstrual periods
  11. Thinning hair
  12. Depression
  13. Reduced memory

If you’re on a quest to become healthier, improve your gut bacteria, reduce your inflammation, and feel/look younger, then you really should consider your thyroid part of that equation. If the symptoms listed above seem very familiar to you, there is a high probability that you’re experiencing thyroid problems. Anyone who has been fighting to improve gut function/gut bacteria and has these symptoms should do some testing and/or start taking a thyroid supplement. An example of a good thyroid supplement, incorporating both the nutritional and glandular component approach, would be this excellent supplement

The best approach to solving the problem is to address as many of the affected systems as possible. This means testing your gut bacteria to see what’s imbalanced, using probiotics and prebiotics, working to improve your autonomic status, controlling stress (and finding fun again!) and a few other critical components.

Tying together all of these potential issues to address may seem like a monumental task…but like many such things it can be broken down into do-able steps and worked with. It’s a bit like solving a Rubik’s cube: one face is gut bacteria, one is lifestyle, one is thyroid status, immune status, chemical exposure, etc. The point is that you cannot change only one of these, and a problem with any of them affects all of the others-also just like a Rubik’s cube!

My upcoming course will provide the tools to address all of these issues. Thyroid is the last component I’m adding to the course (I promise…) so that it can finally be completed and made available. The format will include written material, worksheets, questionnaires, videos…the whole thing to facilitate learning and guiding you to better gut health!

To stay posted on developments and be notified when the course becomes available, please visit my website at and add your name and email to the list to receive updates. I never share/sell emails, so no spam will result!



One thought on “Gut Microbiome-Thyroid: the missing link for gut healing?

  1. Is really is important to make sure that our thyroids have the needed nutrients, vitamins, and minerals needed for them to work as well as they possibly can. Many patients have deficiencies that make it hard for their thyroids. As you mentioned, thyroid supplements can help with this significantly.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.