Gut-Weight Connection, Stress and Thyroid Autoimmunity

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: The Gut-Weight Connection No One Talks About

• Podcast Review: How Stress Contributed to My Graves' Disease Diagnosis

• Understand Your Tests: Understanding Cyrex Labs Array #11

• Ask Dr. Eric: Is it Safe to Eat Gluten in Europe?

The Gut-Weight Connection No One Talks About

There are many reasons why someone might struggle to gain or lose weight. Hormones, diet, and lifestyle all play a role—but one major and often overlooked factor is the gut microbiome. And of course we can’t forget the role that the thyroid plays as well.

Thyroid hormones regulate metabolism, so it’s common for people with hypothyroidism (especially those with Hashimoto’s) to gain weight due to a slower metabolism. On the flip side, hyperthyroidism often causes weight loss because metabolism speeds up.

However, it’s not always so straightforward. Some people with hyperthyroidism gain weight, and some with Hashimoto’s lose weight. This shows that balancing thyroid hormones is essential, but it’s often not the only piece of the puzzle. For many, gut health is the missing link.

How the Gut Microbiome Affects Metabolism

Your gut microbes help your body break down fiber and turn it into short-chain fatty acids (SCFAs) like butyrate. These SCFAs play a key role in:¹

✔️Burning fat for energy (fatty acid oxidation)

✔️Increasing energy expenditure

✔️Improving insulin sensitivity

A healthy gut supports metabolic efficiency. When gut bacteria are imbalanced, these helpful processes are disrupted, making it harder to lose weight and easier to store fat.

Gut Inflammation and Weight Gain

Gut inflammation is another critical factor. It has been linked to higher levels of body fat (adiposity) and insulin resistance—both of which contribute to weight gain.^2,3

A common marker used to assess gut inflammation is fecal calprotectin. While a high calprotectin level confirms inflammation, a normal result doesn’t always rule it out completely.

Two Ways Gut Imbalances Impact Weight in Thyroid Patients

Impaired T4 to T3 Conversion. Gut bacteria help convert T4 (inactive) into T3 (active thyroid hormone). If the gut is imbalanced (a condition known as gut dysbiosis), T3 levels can drop—slowing metabolism and making weight loss more difficult.

Poor Nutrient Absorption. A damaged intestinal lining or low stomach acid can prevent your body from absorbing iodine, iron, selenium, and zinc—all essential for thyroid function and metabolic health.

Gut Dysbiosis, Hunger Hormones, and Estrogen

Your gut influences hormones that regulate hunger and fullness, including:

✔️Leptin – signals fullness

✔️Ghrelin – signals hunger

✔️GLP-1 – helps reduce appetite

When gut bacteria are imbalanced, these signals can be thrown off—leading to increased hunger, cravings, and overeating.

An imbalanced gut can also impair estrogen detoxification. This can cause estrogen dominance, which promotes fat storage, especially around the hips, thighs, and belly.

Other Gut-Related Imbalances That Can Worsen Weight Struggles

✅Candida Overgrowth. You probably know that candida is a yeast that naturally lives in the gut, and it can overgrow due to antibiotics, sugar intake, or weakened immunity. It produces toxins that may impair liver detoxification and lead to cravings—especially for sugar and carbs, which feed the yeast. This can indirectly lead to weight gain and bloating.

✅Small Intestinal Bacterial Overgrowth (SIBO). SIBO occurs when too many bacteria grow in the small intestine. It can cause gas, bloating, constipation, or diarrhea. SIBO is linked to slow motility, poor nutrient absorption, and inflammation, which all interfere with weight balance.

✅Low Stomach Acid. Low hydrochloric acid impairs protein digestion and reduces absorption of nutrients important for thyroid and gut health. It also increases the risk of bacterial overgrowth. Poor protein digestion can lead to fatigue and muscle loss, which slows metabolism.

✅Chronic Stress and Vagus Nerve Dysfunction. Chronic stress affects gut health by weakening the gut lining, slowing motility, and disrupting digestion. The vagus nerve plays a key role in the brain-gut connection and digestion. If it’s not functioning well, it can lead to bloating, dysbiosis, and inflammation, all of which impact weight.

How Gut Imbalances Can Cause Weight Loss

While weight gain is more common in hypothyroid patients, gut issues can sometimes cause unwanted weight loss—in both hypothyroid and hyperthyroid patients. Contributing factors include:

➤ Parasites – May cause malabsorption and nutrient loss

➤SIBO – Can impair digestion and lead to food sensitivities or weight loss

➤Inflammatory Bowel Disease (IBD) – Often leads to poor nutrient absorption and unintentional weight loss

➤Celiac Disease – More common in people with Hashimoto’s or Graves’, this autoimmune condition can damage the gut lining and impair nutrient uptake

How to Support Gut Health to Improve Weight Balance

➡️Identify and Remove Triggers

• Avoid inflammatory foods (gluten, sugar, ultra-processed foods)

• Test and treat hidden infections or overgrowths

➡️Rebuild Digestive Function

• Support stomach acid with digestive bitters or betaine HCl (under supervision)

• Use digestive enzymes if needed

• Practice mindful eating and do things to stimulate the vagus nerve

➡️Rebalance the Microbiome

• Eat a wide variety of fiber-rich, plant-based foods

• Incorporate fermented foods (if tolerated) like sauerkraut or coconut yogurt

• Use probiotics with well-researched strains, such as SMT-Probio

➡️Repair the Gut Lining

• Use gut-healing nutrients and herbs: L-glutamine, slippery elm, marshmallow root, zinc carnosine

• Focus on reducing systemic inflammation

➡️Regulate Estrogen and Detox Pathways

• Support liver and bile flow with foods like beets, dandelion greens, and artichoke

• Ensure daily bowel movements (use magnesium citrate or triphala if needed)

• Increase dietary fiber to bind excess estrogen

Conclusion

If you’re struggling with weight gain or weight loss, it’s time to look beyond just hormones and calories. Your gut may be the missing link. Gut imbalances can slow your metabolism, mess with your hunger cues, block nutrient absorption, and increase inflammation.

By identifying and addressing these imbalances—Candida, SIBO, low stomach acid, and stress—you can improve not only your gut and thyroid health but your ability maintain a healthy weight.

Find Your Hashimoto’s Triggers

If you have Hashimoto’s thyroiditis, visiting an endocrinologist is likely to result in a prescription for thyroid hormone replacement. And while there is a time and place for thyroid hormone, the problem is that it doesn’t do anything for the autoimmune component of Hashimoto’s.

And so what happens is that many people will take thyroid hormone without doing anything to improve the health of their immune system, which means that over time further damage to their thyroid gland will take place.

The good news is that you can do things to reverse the autoimmune component of Hashimoto’s. And the best way to accomplish this is by finding and removing your triggers.

My book “Hashimoto’s Triggers” will show you how to do this. By reading this book you will discover the following:

• More than one dozen triggers of Hashimoto’s thyroiditis

• The different diet options, and how to detect your specific food triggers

• Everything you need to know to heal your gut

• How to reduce fatigue, brain fog, hair loss, lose weight, and address other common symptoms

• Strategies to lower thyroid antibodies when nothing else has worked

• Nutritional supplements and herbs for Hashimoto’s

• A comprehensive list of the blood tests you should get, along with other specific tests that can help detect your triggers

• What you need to do to achieve optimal adrenal health

• Natural treatment options for viruses, pathogenic bacteria, parasites, Candida, and SIBO

Click Here to order the book “Hashimoto’s Triggers”

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 “How can chronic stress affect the gut and the thyroid?” If you’ve been focusing on gut and thyroid health but haven’t given much thought to stress, this is worth checking out.

Based on personal experiences and clinical patterns I’ve seen, chronic stress plays a bigger role than people realize. It’s not about eliminating stress completely— (because that’s usually not realistic), but understanding how it might be affecting your body and what you can do to better support your system. I also share a few simple, practical ideas that might help, especially if things feel a bit stuck.

If progress feels slow despite your best efforts, I really encourage you to give this one a listen. It could shift the way you think about your healing path..

Understand Your Tests

Understanding Cyrex Labs Array #11

In a previous edition of the newsletter I discussed "Testing for Toxicants", and included different types of tests, including the Array #11 from Cyrex Labs. However, recently I had a patient do this test and have a lot of positive findings, which you can see under the Patient Test above.

Just a reminder that while most tests for toxins measure the levels, this measures the immune system response to toxins and toxicants. Obviously anything out of range is considered positive, while those "in range" are considered negative. An "Equivocal" result represents the range between negative and suspicious low positive results.

Loss of Immune Tolerance

This patient has 9 markers out of range, and 8 markers in the equivocal range. So this person has a loss of what's called a "loss of immune tolerance", and so while it would be a good idea for this person to do things to reduce his toxic burden, he also should be doing things to optimize his immune system and gut health.

In the next edition of this newsletter I’ll discuss immune tolerance in greater detail, but the main reason I brought up the Array #11 is because if someone with Graves' disease or Hashimoto's has done everything from a diet and lifestyle standpoint, and also has done a lot of testing to identify triggers, yet hasn’t been progressing as expected, then they might want to consider doing a test like the Array #11.

Ask Dr. Eric

During every issue I'll answer a question or two 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: IS IT SAFE TO EAT GLUTEN IN EUROPE?

Dr. Eric, I've heard that the wheat in the United States isn't the same as it is in other countries because of the glyphosate, and so I wanted to know if it's okay to eat wheat outside of the United States?

This is a common question I hear from patients who are planning a trip to Europe or traveling outside the United States. Many wonder whether they can “get away with” eating pizza or pasta in Italy, or fresh-baked bread in France, without experiencing the same digestive distress they get from eating gluten at home.

Glyphosate Is a Global Issue

First, it’s important to understand that glyphosate, the controversial herbicide found in products like Roundup, is not used exclusively in the United States. While it’s true that glyphosate is more heavily used in U.S. agriculture—especially on wheat and other grains—it is also used in Canada, Australia, China, and even in some European countries.

That said, certain countries in Europe have taken a stricter stance on glyphosate use. In many cases, their wheat products may contain lower levels of glyphosate residue, but that doesn’t necessarily mean they’re completely safe to consume.

But I Felt Fine Eating Gluten Abroad—Why?

If gluten is still gluten, why do some people feel fine eating it in Europe, yet suffer with bloating, fatigue, or joint pain after eating it in the United States?

I recently asked this very question to Dr. Tom O’Bryan, one of the world’s leading experts on gluten sensitivity, during his appearance on the Save My Thyroid podcast. His response was enlightening:

“The reason some people seem to do fine with gluten outside of the United States is because the wheat in the U.S. is higher in FODMAPs, which can trigger gas, bloating, and other digestive symptoms—especially in people with irritable bowel syndrome (IBS) or gut dysbiosis.”

In short, while gluten is still a problem, it may be the added FODMAP burden in American wheat that worsens symptoms. FODMAPs are fermentable carbohydrates that can feed certain bacteria in the gut, causing fermentation, gas, and bloating—especially in people with underlying gut imbalances.

Should You Eat Gluten Abroad?

Ultimately, the choice is up to you. If you're in active recovery from thyroid autoimmunity (such as Hashimoto’s or Graves’ disease), or if you're still healing your gut, you’ll want to think carefully before indulging in gluten-containing foods—even when traveling.

I haven’t yet been to Italy myself, and while I’m now accustomed to gluten-free pizza, I’ll likely try the “real thing” when I visit someday. However, I’ll do so with a full understanding of the possible consequences, and I encourage my patients to do the same.

If you’ve been gluten-free and suddenly reintroduce gluten—whether in the U.S. or abroad—you may trigger intestinal permeability (leaky gut), immune system activation, or symptom flares.

What To Do If You React to Gluten While Traveling

If you decide to eat gluten abroad and experience a flare-up, here are some foods and supplements that can help support gut healing and reduce inflammation:

Gut-Healing Foods

✔️Bone Broth: Rich in collagen, gelatin, and amino acids that help repair the gut lining.

✔️Fermented Foods: Such as sauerkraut, kimchi, and coconut yogurt, which help rebalance gut bacteria (if tolerated).

✔️Cooked, Non-Starchy Vegetables: Easy to digest and gentle on an inflamed gut.

✔️Wild Blueberries & Pomegranate: High in antioxidants to help calm inflammation.

✔️Cabbage Juice: Contains compounds like glutamine that support intestinal repair.

Gut-Healing Supplements

✔️L-Glutamine: An amino acid that fuels cells in the gut lining and supports barrier integrity.

✔️Zinc Carnosine: Helps repair and protect the stomach and intestinal mucosa.

✔️Aloe Vera (inner leaf juice): Soothes inflammation and supports mucosal healing.

✔️Slippery Elm & Marshmallow Root: Plant mucilages that coat and protect the gut lining.

✔️Probiotics: Support microbial diversity, but choose strains carefully—especially if you suspect SIBO.

✔️Digestive Enzymes: Support food breakdown and reduce irritation in the gut.

✔️Curcumin: A powerful anti-inflammatory that can help reduce immune reactivity.

Many of these can be found in my Gut Healing Bundle for thyroid patients, which you can learn more about by visiting GutHealingBundle.com.

Additional Thyroid-Related Resources

Click Here for How Stress Contributed to My Graves' Disease Diagnosis

Click Here Most People Have These Toxins and Don’t Know It (episode 204)

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://pmc.ncbi.nlm.nih.gov/articles/PMC10334151/ 

(2) https://pubmed.ncbi.nlm.nih.gov/30553096/ 

(3) https://pmc.ncbi.nlm.nih.gov/articles/PMC4839080/

That’s a wrap