Thyroid Fatigue, Oxalates, Leaky Gut Testing

Welcome to Healthy Gut Healthy Thyroid!

This is your weekly roundup of the BEST actionable steps for those people with thyroid and autoimmune thyroid conditions who want to restore their health…by healing their gut. Whether you have hyperthyroidism or Hashimoto’s you will benefit from the content in this newsletter.

In today's issue:

• Main Topic: Fixing Fatigue by Healing the Gut and Thyroid

• Podcast Review: Having the Antibodies for Graves’ Disease and Hashimoto’s

• Understand Your Tests: Testing for Yeast/Candida

• Ask Dr. Eric:
  ✔️Do I need to strictly avoid high oxalate foods?
  ✔️How do I know if my gut has been healed?

Fixing Fatigue by Healing the Gut and Thyroid

Fatigue is a common symptom in individuals with Hashimoto's thyroiditis. However, many people with hyperthyroidism also experience fatigue.

While it may seem logical that low or overtly low thyroid hormone levels contribute to fatigue, why do some individuals with elevated thyroid hormones also struggle with low energy levels?

The reason lies in the oxidative stress caused by hyperthyroidism, which can ultimately lead to mitochondrial dysfunction. The mitochondria serve as the energy powerhouses of the cell, and when they become impaired, fatigue is a likely consequence.

Did I Experience Fatigue While Dealing With Graves' Disease?

When I was dealing with Graves' disease, I can't say I experienced significant fatigue. This was true despite my adrenal function being severely compromised, as my saliva test showed low cortisol and low DHEA levels.

Given my poor adrenal function, one might expect that I would have been fatigued. However, if anything, I felt more "revved up," suggesting that my mitochondria were not significantly dysfunctional.

That being said, compromised adrenal function is a major reason why many people experience fatigue. This is one of the reasons I often test adrenal function in my patients, typically through saliva or dried urine testing (i.e., the DUTCH test).

The Impact of Blood Sugar Imbalances

Another common cause of fatigue is blood sugar imbalances. Both insulin resistance and hypoglycemia can contribute to low energy levels.

If you frequently experience fatigue in the early afternoon, there is a strong likelihood that blood sugar dysregulation is a contributing factor. This is also a common reason why individuals wake up in the middle of the night and struggle to fall back asleep.

I will delve deeper into blood sugar imbalances in a future edition of this newsletter. However, while dietary modifications are essential for managing insulin resistance and hypoglycemia, diet alone may not be sufficient. Often, an underlying inflammatory process needs to be addressed, particularly in cases of insulin resistance.

How a Compromised Gut Can Cause Fatigue

Now that we understand how both low and high thyroid hormone levels can contribute to fatigue through different mechanisms, let’s explore the role of gut health in energy levels.

Research has established a connection between fatigue and the gut microbiome, particularly in patients with chronic fatigue syndrome (CFS). A study published in May 2024 concluded:

"The reported associations between altered microbiota composition and cardinal symptoms of ME/CFS and long COVID suggest that the use of microbial preparations, such as probiotics, by restoring the homeostasis of the brain-immune-gut axis, may help in the management of symptoms in both conditions."¹

In other words, taking probiotics may help to alleviate fatigue by restoring balance within the brain-immune-gut axis. While probiotics alone are unlikely to be a complete solution for chronic fatigue, this study reinforces the strong connection between gut health and energy levels.

Fatigue Caused by Nutrient Deficiencies

Certain nutrient deficiencies are also well-documented contributors to fatigue. The following deficiencies have been linked to low energy levels in scientific literature ^{2, 3}:

• Coenzyme Q10

• L-carnitine

• Zinc

• Magnesium

• Iron

• Methionine

• Nicotinamide adenine dinucleotide (NAD)

• Vitamins C, D, and B-complex

An important question to ask is: What causes these nutrient deficiencies?

Identifying the root cause is key to addressing the problem effectively.

For example, as readers of this newsletter know, gut health plays a crucial role in nutrient digestion and absorption. Maintaining a healthy gut is, therefore, a key factor in preventing nutrient deficiencies.

Other Causes of Nutrient Deficiencies

While poor gut health is a significant factor, other contributors to nutrient depletion include:

• Inadequate dietary intake

• Increased toxic burden

• Chronic stress

• Underlying infections

It may seem obvious that a poor diet can lead to nutrient deficiencies, but many people overlook the impact of toxins, stress, and infections. For example, both phase one and phase two detoxification processes rely on adequate nutrient availability. The higher your toxic burden, the more nutrients your body requires to support detoxification.

Similarly, chronic stress and underlying infections can gradually deplete the body's nutrient stores. While a healthy gut is essential, addressing these additional factors may also be necessary.

In summary, fatigue can result from multiple factors, including thyroid imbalances, gut dysfunction, and nutrient deficiencies. Understanding and addressing these root causes—whether through optimizing thyroid function, improving gut health, balancing blood sugar, or replenishing key nutrients—can significantly improve energy levels and overall well-being.

 5 Steps To Reverse Hyperthyroidism and Avoid Radioactive Iodine and Thyroid Surgery

If you have hyperthyroidism (i.e. Graves’ disease, toxic multinodular goiter), visiting an endocrinologist is likely to result in one of the following three recommendations:

1. A prescription for antithyroid medication

2. Radioactive iodine

3. Thyroid surgery

While there is a time and place for conventional medical treatment, it’s crazy that most medical doctors don’t do anything to address the underlying cause of your condition.

The good news is that you can do things to reverse hyperthyroidism, which I discuss in my free webinar entitled “5 Steps To Reverse Hyperthyroidism and Avoid Radioactive Iodine and Thyroid Surgery”.

Click Here to register for the free webinar

Here are some of the things you’ll learn by attending this free webinar:

• How to avoid radioactive iodine and restore your thyroid and immune system health so you can feel great again and live a healthy life!

• The 4 main categories of Graves' disease triggers, and why you shouldn't overlook "hidden" hyperthyroid triggers

• How to break the "hyperthyroid cycle"

• How to address thyroid eye disease and toxic multinodular goiter

Click Here to register for the free webinar

Save My Thyroid Podcast Review

I have a podcast called "Save My Thyroid", where I discuss how people with hyperthyroidism and Hashimoto's can save their thyroid and regain their health. And during each edition of this newsletter I'll briefly discuss a recent podcast episode.

In a recent Q & A podcast episode I answered the question “What approach should I take if I have the antibodies for both Graves’ disease and Hashimoto’s?” Many people have thyroid antibodies for both Graves’ disease and Hashimoto’s, with some combination of the main three types: thyroid peroxidase, thyroglobulin, and thyroid stimulating immunoglobulins.

In this episode I share a brief overview of these antibodies, whether your approach should be different depending on which antibodies are present, why it’s important to address the Triad of Autoimmunity, and the need for individualized strategies for symptom management.

The truth is that many of my patients have the antibodies for both Graves’ disease and Hashimoto’s. And while there is no question that my approach to managing the symptoms of hyperthyroidism and hypothyroidism differ, there is a lot of overlap when it comes to addressing the autoimmune component of Graves’ disease and Hashimoto’s.

Understand Your Tests

Testing for Yeast/Candida

In the previous edition of this newsletter, I discussed yeast overgrowth. Today, I want to dive straight into the different testing methods available for detecting Candida and other yeast overgrowths. Below, I’ll outline three testing approaches, including real patient results.

Testing option #1: Candida Antibodies in the Blood (Test #1). This is the simplest and most accessible method for testing for Candida, though it is my least preferred option.

I recently began recommending this test more often after interviewing Dr. Ami Kapadia on my podcast. She shared how she finds Candida IgG antibodies to be helpful in diagnosing yeast overgrowth. However, keep in mind that Candida IgG antibodies can remain elevated for some time even after the overgrowth has been treated.

Testing option #2: Yeast/Fungi in Stool. Stool testing can detect the presence of Candida, but a negative result does not rule out a yeast overgrowth.

For example, in the test results I included above from a patient (Test #2), Candida species were detected, confirming yeast as a factor in their case. However, because yeast doesn’t always appear in stool samples, this test alone may not be sufficient for an accurate diagnosis.

Testing option #3: Organic Acids Testing (OAT). This is the most reliable method for detecting yeast or fungal overgrowth. In my patient’s test results above (Test #3), three of the nine yeast/fungal markers were elevated, indicating yeast overgrowth.

Arabinose (Marker #7) was elevated, suggesting Candida overgrowth. Two other yeast-related markers were also out of range, with one significantly elevated.

Additionally, the test identifies five markers related to fungi, which are associated with mold exposure.

It’s important to note that organic acids testing detects mold colonization, which is different from urinary mycotoxins testing (previously discussed in this newsletter). OAT does not measure mycotoxins—instead, it reveals whether mold is actively colonizing in the body.

Conclusion: If you're looking for a quick way to screen for Candida, testing for Candida antibodies in the blood is an option. However, for a more comprehensive assessment of yeast overgrowth, the Organic Acids Test (OAT) is the best choice.

Ask Dr. Eric

During every issue I'll answer a few questions that I think can benefit most people with a thyroid or autoimmune thyroid condition. If you'd like for me to consider your question for a future edition of this newsletter email your question to [email protected].

QUESTION #1: DO I NEED TO STRICTLY AVOID HIGH OXALATE FOODS?

Dr. Eric, I listened to your podcast episode on oxalates with Sally K. Norton, and I wanted to know how strict I need to be when it comes to avoiding foods high in oxalates.

For those unfamiliar with oxalates, they are small molecules capable of forming crystals that can accumulate in various parts of the body, including the thyroid gland. These oxalates can impair the function of affected organs or glands. Common areas of accumulation include the bones, blood vessels, central and peripheral nervous systems, retina, skin, and thyroid gland.

During my interview with Sally K. Norton, she highlighted how oxalates may also contribute to dysfunction of the epithelial barrier in the small intestine, potentially leading to or exacerbating leaky gut.

In some cases, oxalates can directly impact thyroid function, while in others, they may contribute to a leaky gut, which is a key factor in autoimmune conditions, as discussed in a previous edition of this newsletter.

As a result, oxalates could be a potential roadblock to recovery. However, this does not necessarily mean you must eliminate them entirely from your diet. That being said, minimizing your intake of high-oxalate foods may be beneficial.

Which Foods Are High in Oxalates?

I plan to explore oxalates in greater detail in a future article, but here are some common high-oxalate foods:

• Spinach

• Swiss chard

• Nuts (especially almonds and cashews)

• Soy

• Peanuts

• Beets

• Sweet potatoes

• Chia seeds

• Collagen (contains hydroxyproline, which is converted into oxalate in the body)

Does this mean you must completely avoid these foods? Not necessarily. For example, I still add collagen to my smoothies, and many of my patients consume sweet potatoes without issues.

As with many dietary topics, opinions vary. I am certain that Sally K. Norton would recommend completely avoiding high-oxalate foods, while others will take a more moderate approach.

Educate Yourself About Oxalates

My goal here is not to provide an exhaustive discussion on oxalates. If you would like to learn more, I have included links to my articles and podcast episodes in the "Additional Resources" section below. I also dedicate a chapter to oxalates in my book The Hyperthyroid Healing Diet.

QUESTION #2: HOW DO I KNOW IF MY GUT HAS BEEN HEALED?

Dr. Eric, is there any way to know if my gut has been healed? Should I do a leaky gut test?

A common question I receive is: "How do I know if and when my gut has healed?"

Years ago, I routinely conducted leaky gut testing to assess intestinal permeability. If a patient tested positive, they could later retest to determine if their gut had healed. While this is still an option, I no longer recommend leaky gut testing for all my patients for several reasons:

Why I No Longer Recommend Routine Leaky Gut Testing

1. Most People with Thyroid Autoimmunity Have Increased Intestinal Permeability. In the past, I frequently used the Intestinal Antigenic Permeability Screen from Cyrex Labs and found that the vast majority of patients tested positive for leaky gut. Rather than having every patient spend hundreds of dollars on such testing, I now assume that most individuals with thyroid autoimmunity have some degree of leaky gut.
   
   Even if a patient doesn’t have leaky gut, the gut-friendly interventions we use won’t cause harm and can still support overall health.
   

2. False Negative Results Are Possible. While the Cyrex Labs test is one of the better options, no test is perfect. Other leaky gut tests, such as the lactulose-mannitol test and the zonulin marker, also have limitations.
   
   For example, an elevated zonulin level on a stool test indicates leaky gut, but a normal zonulin level does not necessarily rule it out.
   

3. These Tests Don’t Identify the Cause of Leaky Gut. A positive result confirms intestinal permeability, but it doesn’t reveal the underlying trigger. Additional testing is often necessary to pinpoint the root cause, such as gut infections, food sensitivities, or stress.

How Can You Tell If Your Gut Has Healed?

Since I don’t rely on leaky gut testing, I evaluate gut healing using the following criteria:

1. Resolution of Digestive Symptoms. While the absence of digestive symptoms alone doesn’t guarantee gut healing, it’s an important factor—especially if symptoms were present initially.
   
   If a patient experiences gas, bloating, heartburn, or other digestive issues, we must resolve these symptoms before considering the gut healed.
   

2. Regular Bowel Movements and Healthy Stool Formation. This also isn't a perfect indication of gut health, and this is especially true in those with thyroid conditions. For example, someone might experience constipation due to hypothyroidism, and not a digestive disorder, and similarly, someone with hyperthyroidism might experience loose stools.
   
   But if someone has balanced thyroid hormones, which is one of the main goals when I work with a patient, we would hope that they would have regular bowel movements and healthy-looking stool. This is especially true if they are eating a healthy diet.
   

3. Normalization of Previously Abnormal Test Results. If a patient originally tested positive for small intestinal bacterial overgrowth (SIBO), H. pylori, or parasites, we would expect negative results upon retesting.
   
   Similarly, if a stool test initially showed opportunistic bacteria, we don’t necessarily expect a perfect result later, but we do aim for significant improvement.
   
   In an earlier edition of this newsletter I also brought up the marker secretory IgA, which in my situation was initial depressed, and eventually normalized. While this isn't a specific leaky gut marker, when it is low it usually relates to a leaky gut.
   

4. Reduction or Elimination of Thyroid Antibodies. For those with Graves’ disease or Hashimoto’s, a key goal is to normalize thyroid antibodies. While this can be challenging, a decline in thyroid antibodies—combined with the other factors mentioned—can be a strong sign of gut healing.

Final Thoughts: Every healthcare practitioner takes a different approach. While I don’t routinely recommend leaky gut testing, some practitioners do. However, if a patient wants to undergo such testing, I have no issue ordering it for them.

Ultimately, assessing gut healing is about more than just a test result—it’s about addressing symptoms, evaluating overall health markers, and ensuring long-term well-being. Thyroid-Related Resources

Additional Thyroid-Related Resources

Click Here for The Impact of Toxic Superfoods (episode 98)

Click Here for Oxalates and Thyroid Health (podcast episode)

Click Here for A Deep Dive Into the Gut Microbiome (episode 101)

Click Here for 5 Things to Know About Oxalates and Thyroid Health (article)

Click Here to access hundreds of thyroid-related articles and blog posts

Click Here to join the Graves’ disease and Hashimoto’s community

Click Here to purchase one of Dr. Eric’s thyroid-related books

Click Here to work with Dr. Eric and his team

References:

(1) https://pubmed.ncbi.nlm.nih.gov/38892479/ 

(2) https://pmc.ncbi.nlm.nih.gov/articles/PMC10181316/ 

(3) https://pmc.ncbi.nlm.nih.gov/articles/PMC7019700/

That’s a wrap