The Hashimoto’s Thyroiditis - SIBO Connection

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The Hashimoto’s Thyroiditis – SIBO Connection

A healthy gut is crucial for optimal thyroid health. The first study of its kind has shown those with SIBO have an increased risk of thyroid autoimmunity. This is good news and suggests that by improving your gut health you can have a healthier thyroid.

Dr. R’s Fast Facts Summary

  • SIBO-D Group TPO 39.9, TPO SIBO – C Group 94.1
    • In both groups of patients the levels of ATPO were statistically significantly higher than in the control group
    • Not clinically significant enough to take action for TPO but indicates that taking action to improve gut health could thereby improve TPO
  • Conclusion: Thyroid function may be impaired in patients with small intestinal bacterial overgrowth which should be taken into account in the diagnostic and therapeutic management of the diseases of these organs.
  • What you can do:
    • Optimize your gut health if you are trying to optimize thyroid health

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Dr. Michael Ruscio, DC: Hi, this is Dr. Ruscio. And let’s discuss more exciting research being published that connects your digestive health to your thyroid health.

study was recently published that examined the association between thyroid function, including thyroid autoimmunity, and digestive health, most namely SIBO (small intestinal bacterial overgrowth). I’ll put the abstract up here on the screen. The study was entitled, “Thyroid Function in Patients with Small Intestinal Bacterial Overgrowth.”

DrMR: And the main finding here, I’ll quote for you. “In both groups of patients, the levels of—” They’re using the abbreviation ATPO, which is anti-thyroperoxidase antibody. So TPO antibodies, the most commonly used measure to assess the severity of thyroid autoimmunity. “—Were statistically significantly higher than in control groups.”

And I’ll continue to their conclusion. “Thyroid function may be impaired in patients with small intestinal bacterial overgrowth which should be taken into account in the diagnosis and therapeutic management of the disease of these organs.”

Now, let’s look at some of the details because the details here do matter. We actually created a results chart from their data. And this is what they found. Now, there’s a lot going on here.

Let me just pull you to the bottom row where it says TPO. And if you look at the TPO as compared to the two different SIBO groups, you see that diarrheal-type SIBO had a level of TPO antibodies of 39. And constipation-type SIBO had an antibody of 94. Now, this is compared to the control of 6. So 6 is considered a normal or acceptable level of the antibody. Usually, the cutoff point is about 30 to 35. So we see that the controls are normal for thyroid autoimmunity. Yet both groups of SIBO patients have abnormal levels of thyroid antibodies.

Now, this is exciting because it further substantiates a connection between the gut and the thyroid. We discussed numerous studies in the past that are starting to elucidate this connection.

But I should also be careful to say that the level of elevation of the antibodies here is not highly significant. Usually, for the level of elevation of thyroid antibodies to be significant, we would want to see someone whose levels are—it’s debatable here. But I think about above 300 for a TPO antibody is when we would want to start taking action. Above 500 would indicate a stronger action should be taken. And when above 1000, it would really indicate that we want to take some type of strong action.

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So the level of severity noted in this study is not hugely, clinically significant. But it does illustrate the connection between the gut and the thyroid. And it’s possible that with more research into this we’ll see a stronger association. It’s also possible that we won’t.

But what this boils down to is we know there’s a connection between your gut and your thyroid. And it would be very prudent to take steps to optimize the health of your digestion, the health of your gut in attempts and as part of a plan to optimize your thyroid health. And I can say, here in the clinic, I am just humbled by how many patients who have been floundering in the world of thyroid treatments, when they come into our office and we optimize for their digestive health, they finally see the symptomatic resolution that they’re looking to see.

And this is not far fetched. We know, for example, that the ability of someone to absorb their thyroid hormone medication is dependent upon healthy digestion. And so part of the reason why people may struggle with levothyroxine and then they try a T4/T3 combination and they never feel like they’ve quite gotten there could in part be due to the fact that they’re not consistently absorbing their medication because their digestion is not optimized. So that’s another angle through which the gut-thyroid connection could be leveraged to improve one’s health.

This is a different angle. This hints at the potential of improving thyroid autoimmunity. We do have one treatment study that has shown that the treatment of H. pylori can lower thyroid antibodies.

Thyroid Gut Connection

So we’re still new here in our understanding. But we’re definitely seeing numerous data points that associate digestive health to thyroid health.

Now, are the data here super strong and compelling? No. However, do we need to have a very strong case to defend the recommendation to optimize one’s gut health? I don’t think so, especially because when we optimize one’s gut health, we oftentimes see other improvements, namely any digestive symptoms go away. And also things like clearer skin, more optimal moods, better energy, and what have you.

So here we’re seeing some very exciting evidence showing that small intestinal bacterial overgrowth, a digestive condition, connects to thyroid autoimmunity. And I would speculate that by improving one’s SIBO or digestive health in general, we could expect to see an improvement, not only in global symptoms but also in thyroid autoimmunity.

So this is Dr. Ruscio. And I hope this helps you get healthy and get back to your life.

➕ Links & Resources
  • Konrad P, Chojnacki J, Kaczka A, Pawłowicz M, Rudnicki C, Chojnacki C. Ocena czynności tarczycy u osób z zespołem przerostu bakteryjnego jelita cienkiego [Thyroid dysfunction in patients with small intestinal bacterial overgrowth]. Pol Merkur Lekarski. 2018 Jan 23;44(259):15-18. Polish. PMID: 29374417.
  • BIOHM Health Probiotic Supplements
  • Dr. Ruscio’s Additional Resources

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