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Your Thyroid Isn't the Problem — Your Gut Is | Dr. Cassie Smith

The Dr. Josh Axe Show

Hosted by Josh Axe

58m
Transcript

Original podcast

Summary

Written by a model from the transcript; not yet reviewed.

This episode explores the deep connection between gut health, lifestyle factors, and hormone imbalances, arguing that many conventional thyroid and hormone treatments fail because they address symptoms rather than upstream root causes. The host and the guest discuss how synthetic hormones like birth control, chronic stress, poor diet, and medications can damage the gut microbiome, trigger leaky gut, and impair the body's ability to convert thyroid hormones or regulate insulin and cortisol. Listeners will gain actionable insights into essential lab markers often overlooked by doctors, the recently updated classifications of PCOS, and why a personalized, root-cause protocol is critical for true healing.

  • Request a comprehensive thyroid panel including free T3, reverse T3, and TPO antibodies rather than relying solely on TSH. 3:49
  • Aim for a ferritin level of at least 70 to ensure your cells can properly utilize thyroid hormones. 11:24
  • Ensure you are having a daily bowel movement and supporting your estrobolome to properly excrete hormone metabolites. 30:05

Chapters

  1. 0:00
    Episode Introduction and Giveaway Announcement

    Josh Axe opens the show, thanks listeners, and announces a $5,300 prize giveaway to boost engagement.

  2. 2:02
    Introducing Dr. Cassie Smith and Episode Focus

    Josh introduces his guest, Dr. Cassie Smith, and outlines the episode’s goal of uncovering root causes of hormone issues.

  3. 2:53
    Root Causes of Hypothyroidism and Autoimmunity

    Dr. Smith explains that 80% of hypothyroidism is Hashimoto’s and discusses why doctors often miss underlying autoimmune and gut issues.

  4. 35:03
    Closing and Resources

    Josh thanks Dr. Cassie, promotes her book and resources, and encourages listeners to subscribe and share the episode.

  5. 45:32
    Intro and Promotion

    Josh Axe opens the episode, promoting his cellular blood work kit and setting the stage for the discussion.

  6. 47:57
    Gut Health and Hormone Metabolism

    They explore how gut health, B vitamins, and glutathione influence hormone processing and the risk of toxic metabolites.

  7. 49:30
    Prescription Practices and Patient Safety

    Discussion on the current prescribing habits for hormones, the need for lifestyle assessment, and the concept of malpractice when ignoring gut health.

  8. 55:09
    Medical Education Gaps

    The hosts critique medical school curricula, highlighting the lack of training in nutrition, gut health, and functional medicine across all health professions.

Highlights

  • 0:00

    Hashimoto's and Hypothyroidism Root Causesinsight

    Around 80% of hypothyroidism cases are actually Hashimoto's thyroiditis, yet traditional medicine rarely addresses the root autoimmune causes.

  • 4:40

    Birth Control and Thyroid Riskdata

    Synthetic hormones from birth control disrupt the gut microbiome, leading to leaky gut and a significantly increased risk of developing hypothyroidism.

  • 6:22

    The Mechanism of Gut Leakageinsight

    Bad gut bacteria release lipopolysaccharide when gut integrity is damaged, which triggers chronic immune activation and interferes with thyroid hormone conversion.

  • 17:52

    Morning Cortisol Rangesdata

    Standard medical lab ranges for morning cortisol are so wide that they fail to catch chronic stress and adrenal issues.

  • 22:56

    Low Testosterone and Cardiac Risksdata

    Low testosterone combined with low vitamin D dramatically increases overall cardiac mortality risk according to Framingham data.

  • 29:24

    PCOS Reclassification and Typesinsight

    PCOS was officially reclassified as polyendocrine metabolic syndrome, recognizing that there are actually seven different types driven by factors like gut health, cortisol, and post-pill issues.

  • 39:57

    Biochemical Byproducts of Thyroid Productioninsight

    Making thyroid hormone naturally creates peroxide as a byproduct, which requires adequate antioxidants and methylated B vitamins to neutralize without damaging cells.

Quotes

  • “triggers because 70% of our immune system lives outside of our gut.”
    Unnamed speaker · 6:34
  • “I think the Hashimoto's develops because of the intense gut and immune issue that we have from, you know, leaky gut.”
    Unnamed speaker · 7:06
  • “Ferritin is what takes T3 into the cell.”
    Unnamed speaker · 10:52
  • “I think insulin resistance is the reason that we age, we get disease and we ultimately die.”
    Unnamed speaker · 16:11
  • “A hormone is going to act in the environment you put it in.”
    Unnamed speaker · 46:45
  • “We need to, you know, be monitoring those levels.”
    Unnamed speaker · 50:39
  • “If you're not asking those questions, and if you are getting hormone replacement therapy, and somebody's not asking you that, it's kind of malpractice, in my opinion.”
    Unnamed speaker · 50:58
  • “We are getting almost zero training in how to practice what I would call true medicine, root cause medicine.”
    Josh Axe · 53:10
  • mybloodwork.com 45:01–45:30
  • Amazon.com 56:10–56:43
  • modern-indocrine.com 57:12–57:40
  • subscribe 57:51–58:16

About this episode

What if your labs look “normal,” but you still feel exhausted? Dr. Cassie Smith joins Dr. Josh Axe to share how her own experience with Graves’ disease shaped her approach to hormone health. They explore the gut-hormone connection, hypothyroidism, PCOS, insulin resistance, and hormone replacement therapy—and discuss what persistent fatigue, thinning hair, and difficulty losing weight may warrant investigating.

Transcript

0:00
58:35

11,816 words · 2 speakers

Speaker names marked are inferred from speaking time and the show’s known hosts — they are not voice-verified.

Topics

  • WHO
  • glutathione
  • B vitamins
  • estrobolome
  • TrustPilot
  • Fix Your Gut, Fix Your Hormones
  • Life University
  • Modern Endocrine
  • hyperbaric oxygen therapy
  • red light therapy

Page updated · transcript and summary are machine-generated