SIBO, known as small intestinal bacterial overgrowth is a condition in which there is too much bacteria in the small intestine. In my practice, I see many patients suffering from gut health issues which often coincides with thyroid disease. There are a number of gut health issues that can affect the thyroid, and there is a connection between SIBO and the thyroid.

Let’s start by talking more about this condition and then talk about how it affects the thyroid.

What is SIBO?

As mentioned before, SIBO is a condition in which there is too much bacteria in the small intestine which can lead to things like poor nutrient absorption, as well as damage to the stomach lining. SIBO can also cause many unwanted symptoms such as those associated with Irritable Bowel Syndrome.

The important thing to know about the bacteria in our gut is that it is normal to have a certain level of bacteria in the gut. In fact, we want a certain amount of healthy bacteria to help keep our digestive health strong and healthy. However, the small intestine happens to have lower levels of bacteria so when there is a bacteria overgrowth in the small intestine, SIBO may be present.

To help you better understand SIBO, let’s talk about the small intestine. The small intestine is the longest part of the digestive tract. This is also where nutrients are absorbed into the blood stream. (1) When someone suffers from SIBO, it may lead to malabsorption of nutrients due to the bacteria overgrowth in the small intestine. One of the tricky things about this condition is that some of the bacteria overgrowth that is present with SIBO can consume some of the nutrients which ultimately lead to a number of very unpleasant symptoms which we will talk about next.

SIBO is often treated with antibiotics, however, in functional medicine, we use a more holistic approach that involves methods of tackling this condition and dealing with it at its source. While SIBO can be a challenging condition to control there are many dietary and lifestyle changes that can be implemented to help get your gut bacteria back in balance.

SIBO Symptoms

The symptoms that come with SIBO are often similar to conditions such as Irritable Bowel Syndrome. Here are some of the commonly seen symptoms:

  • Bloating
  • Gas
  • Abdominal pain
  • Malnutrition
  • Diarrhea
  • Nausea/vomiting
  • Food intolerances
  • Weight loss
  • Joint pain
  • Fatigue
  • Skin issues


SIBO Causes

What causes SIBO? There are a handful of different things that are thought to lead to SIBO. Things like diabetes, diverticulosis, or even aging are thought to be some of the leading causes of this condition.

Medications may also be to blame here especially medications like proton pump inhibitors used for GERD, or immunosuppressants. Things like having a recent abdominal surgery, or having Celiac disease can also increase your risk of developing SIBO.

SIBO Diagnosis

Whenever a patient comes to my practice with gastrointestinal symptoms I will always check for gut infections, and this includes SIBO. Being that the gut bacteria in our gut plays such a crucial role in the health of every other part of the body, including the thyroid addressing gut health is one of the most important steps in feeling better.

SIBO and the Thyroid

So, what does SIBO have to do with the thyroid? First and foremost, gut health and thyroid health are connected. Having thyroid issues such as hypothyroidism can actually cause SIBO. When you are dealing with a thyroid condition such as hypothyroidism, your thyroid is not performing the way that it should be. This means that your metabolic processes slow down and this includes digestion. (2)

One of the most common symptoms of hypothyroidism is constipation. Unfortunately, being chronically constipated can lead to an overgrowth of harmful bacteria. Not only that, but many people who suffer from hypothyroidism also have lower levels of stomach acid, HCL. HCL helps us digest food so when we do not have enough it can be easy for the pathogenic bacteria in the gut to grow.

There is another connection between SIBO and the thyroid and that is the opposite of what we were just talking about. SIBO can also lead to hypothyroidism. Since about 21% of T4 to T3 conversion occurs in the gut, problems can occur when you do not have optimal gut flora. When your gut is dealing with an overgrowth of harmful bacteria this can cause issues with the T4 to T3 conversion which can then lead to hypothyroidism.

The SIBO and thyroid connection is huge and unfortunately, it can lead to hypothyroidism but hypothyroidism can also lead to bacterial overgrowth. The best thing to do if you suspect you have either one of these conditions is to work with a functional medicine practitioner to get the proper testing to uncover if SIBO is affecting the health of your thyroid. In my practice, I offer extensive gut health testing and based off of the test results, I develop an individualized plan to address each patients unique health needs.

As you can see, gut health is directly related to the health of our thyroid and when there is an imbalance in the bacteria in our gut, it makes it harder to deal with a thyroid imbalance. The good news is that although SIBO is a difficult condition to get under control, there are some steps you can take. First, I want to talk about the different approaches to dealing with SIBO. The modern medical approach and then the functional medicine approach so that you can see the difference between the two and how a holistic approach is the only way to tackle SIBO.

Traditional Medicine Approach

If SIBO is detected in a modern medical practice there is a good chance that a patient will be prescribed antibiotics. The problem with this is that even with the use of antibiotics, SIBO can be very difficult to get under control and a healing dietary and lifestyle protocol need to be put into place. Not including dietary changes can make getting SIBO under control very difficult and you will learn why, so keep reading.

There was a study that showed that those who suffered from SIBO who were only prescribed antibiotics actually had a higher recurrence rate. (2) The problem here is that prescription antibiotics may not be enough to really deal with this digestive condition at its source.

The great news is that there is a different way of going about getting SIBO under control and that’s with the use of functional medicine. Let’s take a look at how a functional medicine approach to dealing with SIBO is much different from the modern medical approach.

Functional Medicine Approach

In functional medicine, we use a holistic approach to addressing disease including things like thyroid disease and gut infections. The first step we take is to offer the proper testing to determine if SIBO is causing some or even all of your symptoms.

After the test results come back, I often work with patients to eliminate certain foods from their diet such as sugar, refined carbohydrate, gluten, and alcohol. I also recommend a soil-based probiotic. These are important for overall gut health as they will help to give the healthy bacteria in your gut a boost while your body is working to rid itself of the harmful bacteria overgrowth that may be occurring in the small intestine. We also work on addressing specific dietary needs and come up with a lifestyle plan to get the SIBO under control as quickly and efficiently as possible. It takes some patience to get SIBO under control but with the right changes, it can be done.

The SIBO Diet

There is actually a specific dietary approach that many people with SIBO find very beneficial. You may be familiar with the FODMAPS diet. This diet focuses on removing FODMAPS from the diet which are fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. Don’t worry about understanding what each of those terms mean. Just know that FODMAPS are fermentable short-chained carbohydrates and they are not very well absorbed in the gut. (3) They are sugars that are found in certain foods and in those with SIBO they can make symptoms worse. These foods can actually ferment in the digestive tract which is the very last thing you want when you are already dealing with a bacterial overgrowth. When these foods ferment, they can feed the bacterial overgrowth and then make your SIBO symptoms worse or make it much more difficult to get this condition under control. **While some people find this diet helpful, I do not typically use this diet in my practice. Instead I stick with a diet high in foods like this and typically have great success with this approach:

  • Eggs
  • Grass-fed beef
  • Grass-fed lamb
  • Free-range chicken & turkey
  • Wild caught fish
  • Cucumbers
  • Lettuce
  • Carrots
  • Bananas
  • Oranges
  • Blueberries
  • Coconut oil
  • Avocado oil
  • Sprouted nut butters


Action Steps

Along with getting the proper testing, there are some other things that you can do to help control SIBO through dietary and lifestyle changes. Here are a couple of steps you can take today using a functional medicine approach to tackling SIBO:

  • Eliminate sugar, gluten, and refined carbs
  • Avoid diary
  • Supplement with a soil based probiotic
  • Consume smaller amounts of foods during meal time and eat 5-6 times per day instead of 3 large meals per day
  • Do not overeat
  • Take digestive enzymes like Digest Care

Digest Care is comprised of a proprietary blend of digestive enzymes along with betaine HCl to support optimal digestion of proteins, fats, and carbohydrates. This product contains the special protease DPP IV (dipeptidyl peptidase IV), which aids in the breakdown of the peptides gluteomorphin (from gluten) and casomorphin (from casein). Digest Care also includes the enzyme lactase, which helps break down the dairy sugar lactose. The use of Digestzymes™ before meals may be helpful when patients experience gas and bloating after eating, constipation, or a feeling of fullness after eating only a small quantity of food.*

If you are suffering from weight gain, fatigue, hair loss and more, click here to schedule a phone call with me, so I can find out where you’ve been, where you want to get to, and how I can help you get there.

I know exactly where you are because I’ve been there myself…I remember being so tired that I could barely function. I gained 30 pounds out of nowhere and had a severe case of brain fog. I also started to get severe anxiety and panic attacks. I was driven and motivated…until I wasn’t. I didn’t know what was happening to me. All I wanted was to get my life back…

Finally, I learned about functional medicine and found a practitioner that I hoped could help me. They ran specialized tests that were far different than I had ever had before. When I got the results back, it turned out I had candida, parasites, high cortisol, the Epstein Bar Virus and many food intolerances. I also had an issue with my thyroid that no one found before because they were using the conventional medicine lab ranges which are way too broad….which I now know is one of the leading causes of hypothyroid misdiagnosis.

I went through treatment of all of these things and it completely changed my life.  I immediately lost the 30 pounds I had gained plus more, I had a lot more energy, and my brain fog was gone. I felt amazing and knew that I wanted to help people find the underlying causes of their symptoms and disease.


  • Axe. Do You Have SIBO Symptoms? Here is ALL You Need to Know.
  • Amy Myers. The SIBO and Hypothyroidism Connection.
  • Axe. What are FODMAPS? The Key to Heal IBS?