Informational Posts / My Personal Experiences

Leaky Gut, Candida and Autoimmune Hypothyroidism

Originally published on 23rd January 2018
Last updated on 26th February 2024

Is “leaky gut” a thing? What is the connection to thyroid conditions? And what does it mean to improve our gut health?

Klikkit Buttons Reminding Rachel to Take Supplements

Gut Health: A Puzzle Piece

As well as being on the correct type of thyroid medication for you and finding the optimal dosage, it’s also important to address other factors that can be contributing to you feeling unwell

I thought for a long while that once I got my thyroid levels optimised (on NDT medication), I would return to the level of health and fitness that I had before, but I didn’t.

Even with optimal thyroid hormone levels, I still had ongoing fatigue, poor stamina, cystic acne, irregular periods and more, which suggested that I needed to look at other issues and areas within my body. After all, there is often so much more to the thyroid jigsaw puzzle than thyroid medication alone. 

A lot of research led me to many possibilities, and I soon started piecing together my own thyroid jigsaw puzzle, including low vitamin and mineral levels, a blood sugar spiking diet, poor sleep hygiene, high cortisol levels and poor gut health.

“Leaky gut” is a term we hear a lot in the wellness space and is said to be a common issue for thyroid patients, but what is it?

What is “Leaky Gut”?

Hippocrates, a Greek Physician often considered to be one of the most outstanding figures in the history of medicine, said “All disease begins in the gut” and  2500 years later, we’re now understanding just how right he was.

Poor gut health can suppress thyroid function and be a contributing trigger for Hashimoto’s.

However, the term ‘leaky gut’ can be unhelpful. You see, our gut is always ‘leaky’, in order for our body to absorb what is needed from food. So we actually need our gut to be ‘leaky’!

The term, ‘increased intestinal permeability’ is much more accurate and specific, and describes a gut which things can more easily pass through, and this can play a role in digestive issues and autoimmune conditions (like Hashimoto’s).

Increased intestinal permeability can occur from hypothyroidism, microbial dysbiosis, infections, antibiotics use, inflammatory bowel disease, food intolerances (such as gluten), stress, etc. 

Symptoms of increased intestinal permeability can include:

Symptoms can be tailored to the individual and in my case, I experienced fatigue, poor stamina, cystic acne, mental health issues and chronic constipation. 

I suspect I’ve had gut issues most of my life, and this likely contributed to the triggering of Hashimoto’s at sixteen-years-old. 

Why Is the Gut Important in Thyroid Health?

The gut assists in converting inactive thyroid hormone T4 to active T3 (which is what we need for energy and many functions within the body), which requires an enzyme called intestinal sulfatase.

However, this enzyme comes from healthy gut bacteria. An unhealthy gut can lead to a lack of this important enzyme.

Intestinal dysbiosis is an imbalance between pathogenic and beneficial bacteria in the gut, which can significantly reduce thyroid hormone conversion – just one reason why people with poor gut health may have thyroid symptoms but ‘normal’ TSH test results. [2]

Any inflammation within the gut can also lead or contribute to adrenal dysfunction, another puzzle piece. So let’s look after our guts!

What is Candida?

Candida, a yeast overgrowth, is a form of Intestinal dysbiosis. This condition means that you have an overgrowth of yeast in your body, which may cause all kinds of issues and be giving you poor gut health.

Yeast exists in the gut naturally and, in the right amount, isn’t an issue, but high stress, antibiotics and too much sugar or a diet high in processed food can cause it to thrive and become power hungry.

Do you have hormonal issues? Still feel fatigued despite being on thyroid medication? Feel stressed a lot? Have any other ongoing symptoms? Please do check for candida. 

A UK test for Candida can be found here. and a US test here.

The Signs I Had Candida

For me, my usually regular periods started to become massively irregular and could come at any time. At twenty-two, I also began breaking out in severe, cystic acne. I’m not talking a few pimples, I mean that so much of my face was covered in these deep, painful cysts, that they joined up to cause mountains of pain on my cheeks. They left deep scarring and bruising that has lasted years.

A close up photo of Rachel showing acne covering her chin

Doctors checked for STI’s, PCOS and even ran bloods on my sex hormone levels and I was found to have an imbalance of too much oestrogen, along with Candida.

I was told that poor gut health with a sex hormone imbalance wasn’t unusual, since a very stressed out gut may lead to high cortisol adrenal dysfunction, which also impacts, causes and worsens hormonal imbalances such as that of oestrogen and progesterone, creating a bad cycle.

In my case, dysbiosis had occurred following extremely high stress levels for years (both mentally and physically), a high sugar and low fibre diet and multiple rounds of antibiotics.

My first appointment with a functional medicine practitioner confirmed the overgrowth but trying to pin-point when exactly it started was hard, since I’d never passed bowel movements regularly enough (just once every 1-2 weeks my whole life) and it was most likely in place to help trigger my Hashimoto’s at sixteen-years-old.

How Do You Treat Candida and Increased Intestinal Permeability?

Once confirmed as having increased intestinal permeability thanks to Candida, I was guided on a gut-health-supporting programme by the functional medicine practitioner.

What she advised:

  • To take probiotics daily to replenish the good bacteria in my gut, probably as a lifelong supplement but to review from time to time.
  • To up fibre and water intake substantially. Eat a rainbow of fruit and veggies! Your gut loves food diversity.
  • Epsom salts in baths to support adrenals.
  • Digestive enzymes to help move things along my gut and absorb nutrients from my food properly, for the next few months only / until they were no longer needed.
  • Apple cider vinegar to support stomach acid production, for the next few months / until it was no longer needed.
  • Grapefruit Seed Extract or oregano oil, a natural remedy to clear the body of excess yeast (taken in milk), for the next few months / until it was no longer needed.
  • To drink bone broth daily to reduce permeability again / ‘heal’ the gut lining. For as long as I wanted to carry it on for.

I also cut out alcohol, followed a very low sugar ‘candida diet’ (see this link on the exact foods my functional medicine practitioner included on this diet), and implemented helpful foods such as anything high in protein and fibre, chia seeds, coconut oil, turmeric, cinnamon, flaxseed, hemp oil, oregano and garlic, all to support my gut health and the process of overcoming candida.

Supplements that can also boost the body’s resistance to yeast include folic acid, Vitamin C, Zinc, Pyridoxal-5-phosphate, Vitamin A, riboflavin, magnesium and selenium. Caprylic acid is a naturally occurring anti-fungal found in coconut oil which can also help combat candida, as it kills off bad organisms but doesn’t affect useful organisms.

Zinc supplementation may also help to tighten the intestinal junctions of those with increased intestinal permeability.

How Long Does it Take To Overcome Gut Complaints?

For a lot of people, following this kind of programme for a few months is long enough to restore the correct balance of yeast and good bacteria in the gut, but for some, it can take longer. It of course also depends on how strictly you’re following the advice of your healthcare team (I saw a functional medicine practitioner) and how severe your case is. 

I felt much better after a few months and then moved on to maintaining that good gut health.

After the balance has been restored, you can often reintroduce more foods, but bearing in mind that you’ll need to promote good gut health going forward, so as not to relapse again.

However, if you have any gut health complaints, it is still really important to see a doctor to be assessed for IBS (irritable bowel syndrome), IBD (irritable bowel disease), among other possibilities. Don’t delay seeking help based on ‘leaky gut’ information and supplements.

Do you have experience with gut issues?

You can click on the hyperlinks in the above post to learn more and see references to information given.





About Author

Rachel Hill is the highly ranked and multi-award winning thyroid patient advocate, writer, speaker and author behind The Invisible Hypothyroidism. Her thyroid advocacy work includes writing articles, authoring books, producing her Thyroid Family email newsletters and speaking on podcasts and at events about the many aspects thyroid disease affects and how to overcome these. She is well-recognised as a crucial and influential contributor to the thyroid community and has a large social media presence. Her bestselling books include "Be Your Own Thyroid Advocate" and "You, Me and Hypothyroidism".


  • Lanie
    November 25, 2020 at 12:07 pm

    I was diagnosed last week with inflammation of stomach intestines and colon. Had a gastronomy and colonoskopy. Dr put me on antibiotics and ant inflammatory meds. Is this because of leaky gut? And how good is for me to have to drink the meds for 28 days.

  • Jenny Allen
    March 14, 2019 at 8:25 pm

    This article has been really helpful. I had Postpartum Thyroiditis, had overactive, then underactive thyroid and after 14 months function returned to normal with a good degree of health for several weeks. Lately I have return symptoms, tsh moving towards over active again but still in normal and so no more can medically be done about this. I am seeking health feom a nutritionist who is going to do a stool test and look at gut health. My tinge is always fury and has a funny feeling up the side and I am in a world of not right again. This article has reassured me in terms of the importance of gut health (I too have done a lot of reading about it).

    • Rachel Hill
      March 14, 2019 at 8:27 pm

      So glad it has helped Jenny. Hope the nutritionist can give you some more answers and guidance. Gut health is so important, as you know.

  • Nadia Evans
    October 7, 2018 at 8:53 pm

    There is definately a great deal to learn about this issue. I like all of the points you have made.

  • Paula A Lawrence
    August 30, 2018 at 4:43 pm

    Do you use the epsom salts for a bath? If so, do you use plain or do you use them with essential oils? What digestive enzyme do you take? I too, am struggling with a candida overgrowth and treating currently, with food, probiotics, and acv. Doc gave me 7 pills for diflucan for 14 days, but that just seems to be too harsh on the liver to take for that long. Have you ever tried prescription medicine to help?


    • Rachel Hill
      August 30, 2018 at 6:12 pm

      I use Epsom Salts in baths and foot soaks a couple of times a week. I use Archturus digestive Enzymes, 3 days a time. For leaky gut issues and Candida, conventional medicine don’t really do anything for it, so I see a functional medicine practitioner who prescribes what I need for the programme.

  • Paula
    August 15, 2018 at 12:59 am

    I have Hashimoto’s & testing showed Overactive Candida. I don’t have a high sugar diet unless you count fruit. Never on antibiotics. Anxiety is not too extreme either. Surprised I have it. As a vegetarian it would be tough to give beans or grains but if the functional medicine doctor says I have to I will figure it out. Hope you share more on this topic.

    • Rachel Hill
      August 18, 2018 at 12:26 pm

      Hope you manage to balance your Candida soon Paula

  • Teresa Joanette
    June 26, 2018 at 5:28 am

    That is very interesting, You are an overly skilled thyroid blogger. I’ve joined your newsletter and look forward to seeing more of your wonderful posts. Also, I have shared your website on my social networks!

    • Rachel Hill
      June 26, 2018 at 9:15 am

      Ah thank you!

  • Milo Karageorge
    June 22, 2018 at 3:19 am

    Hello there! This is my first comment here so I just wanted to give a quick shout out and say I truly enjoy reading through your posts. Can you suggest any other blogs/websites/forums that go over the same subjects? Thanks!

  • Amanda Patrick
    May 9, 2018 at 4:32 pm

    Oh my goodness! We have the same story. I was struggling with a slow thyroid, cystic acne, fatigue, migraines, and brain fog. I finally realized it was my gut causing all the trouble, candida, and bad bacteria were overtaking me. It’s been a journey of eliminating the candida so I could think clearly again. So glad you are feeling better.

    • Rachel Hill
      May 22, 2018 at 2:52 pm

      Glad it has helped you too! It’s crazy how involved our gut health is!


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