If you’ve been feeling sluggish, foggy, or exhausted, your gut could actually be playing a bigger role than you realize. Scientific research points to a fascinating connection: a percentage of thyroid hormone conversion happens in your gut. That means when your gut is inflamed or out of balance, your thyroid may struggle to keep up, leaving you with symptoms even when traditional labs look “normal.”


The Gut-Thyroid Connection: What the Research Shows


Here’s what we know:

 • Research shows that a percentage of the conversion of inactive thyroid hormone T4 into active T3 happens in your gastrointestinal tract, thanks to gut microbes and an enzyme called intestinal sulfatase. This process is essential, because T3 is what powers your energy, metabolism, and mood, and is the active thyroid hormone.

 • When gut bacteria are out of balance, what is known as dysbiosis, or when inflammation is present, the efficient conversion that normally happens, drops off. So, even if your thyroid gland is healthy, you could feel hypothyroid-like symptoms due to poor T3 availability.
 
 • The gut also supports your immune system: it’s home to 70% of your body’s immune tissue (gut-associated lymphoid tissue, or GALT). Therefore, if your gut barrier is compromised, as in “leaky gut,” inflammation can occur and this can trigger or worsen autoimmune thyroid conditions like Hashimoto’s or Graves’ disease. Having this overactive immune response can also trigger allergy-type symptoms and histamine responses.

 • Studies also show people diagnosed with hypothyroidism are more likely to have small intestinal bacterial overgrowth (SIBO)—33% compared with 15% in those without thyroid issues. Having SIBO can further worsen gut inflammation and the way your body processes hormones, causing hormone disruption.

Gut Inflammation Slows Your Thyroid—Here’s Why That Matters


When your gut is inflamed, here’s what happens:

 1. You convert less T4 into T3 (active thyroid hormone), which can leave you low on the hormone that powers your energy and metabolism, leading to fatigue, bloating, and weight gain.

 2. Your immune system may go on high alert. Breached gut barriers often trigger immune reactions, since you have more proteins floating around from the gut into the rest of your system, which can lead to worsened autoimmune attacks on your thyroid.

 3. You can experience thyroid symptoms even with normal labs like fatigue, weight gain, brain fog, cold sensitivity, especially if the gut is compromised in some way with SIBO or leaky gut.

Think of your gut as a partner with your thyroid that needs to also be looked at and treated. When your gut isn’t functioning optimally, your thyroid and thyroid hormones may be slower, even if your thyroid gland is structurally sound.

What You Can Do From Scottsdale to Anywhere


If you’re in Scottsdale or beyond, these gentle, grounded steps can support your gut-thyroid axis:

1. Support beneficial gut bacteria

Certain probiotic strains such as Lactobacillus and Bifidobacterium are great probiotics for thyroid health, and have been shown to support gut balance. They may also aid thyroid hormone conversion since these bacterium are often low in hypothyroidism.

2. Nurture your gut lining

Focus on nutrient-dense, anti-inflammatory foods, consisting of whole produce, healthy fats, minimal sugar, and lean proteins. The Mediterranean diet has been shown to have positive influence on normalizing thyroid hormones, especially for those with subclinical hypothyroidism.

3. Work to restore gut balance

If you’re experiencing SIBO or dysbiosis, addressing overgrowth and easing gut inflammation is key, not just for digestion, but for thyroid health, too.

4. Heal the immune terrain

Supporting gut barrier integrity helps calm overactive immune responses and that can help to reduce autoimmune attacks on the thyroid.

5. Get personalized guidance

Each gut-thyroid story is very different, especially since everyone’s immune systems and gut integrity are vastly different. Working with a qualified practitioner, especially one experienced in gut-thyroid connections, can help you uncover the unique steps your body needs.

If you’re ready to get started and get some answers, especially if you’re looking for gut and thyroid support in Scottsdale, AZ, you can grab your spot on an alignment call with me here.

Final Thoughts


When gut inflammation interferes with the conversion of T4 to T3, it can leave you low on the hormone that fuels your energy and vitality, even if your thyroid gland itself is functioning.

By nurturing your gut through balanced nutrition, calming inflammation, and supporting microbial balance, you’re creating balance with better gut and thyroid health. While you may be able to make some progress on your own, it's suggested to get the right testing and treatment from a healthcare provider that resonates with you.


Frequently Asked Questions (FAQs)

Dr. Valerie Gettings in a white suit sitting on chair, smiling confidently in a modern office setting with natural light.

About the Author


Dr. Valerie Gettings, NMD, PLLC

Naturopathic Medical Doctor | Gut & Thyroid Health


Dr. Valerie Gettings is a Scottsdale-based naturopathic doctor who helps high-performing women resolve gut and thyroid issues so they can feel clear, energized, and fully themselves again. Through her evidence-based Gettings Gut Health Method, she blends clinical expertise with individualized, root-cause medicine to restore energy, balance hormones, and support whole-body wellness, so her patients can live an adventure-filled life.


If you’re ready to finally get answers about your gut or thyroid symptoms, you can book an Alignment Call with Dr. Gettings here.