Have you ever experienced bloating so bad that you can’t button your pants? If you experience gas or bloating regularly or are dealing with IBS, there’s a strong likelihood you may have SIBO or Small Intestinal Bacterial Overgrowth. Even if you don’t experience abdominal swelling to an extreme, any amount of bloating is not normal — it’s a sign of intestinal inflammation, and it could likely be SIBO. My patients commonly told me that they woke up with a flat belly and by the end of the day they looked six months pregnant.

Before we get to the step-by-step process to help eliminate SIBO, it’s important to know how to spot it and identify SIBO symptoms.

What is SIBO?

Small Intestinal Bacterial Overgrowth, or SIBO, occurs when the bacteria in your small intestine become unbalanced and overgrow.

The bacteria in your GI tract, which make up your gut microbiome, play a vital role in your immune system, thyroid function, bone health, and overall health. In fact, scientists discovered that the gut microbiome contains tens of trillions of microorganisms, including up to 1,000 different species of bacteria with over 3 million genes.

Most of your gut bacteria are meant to be located in your large intestine and colon, where they help break down food, synthesize vitamins, and eliminate waste. When bacteria normally found in the large intestine and colon begin to colonize the small intestine, bacterial overgrowth occurs.1 Small intestinal bacterial overgrowth can also occur when there is an overgrowth of otherwise normal bacteria in the small intestine itself.

How SIBO, or small intestinal bacterial overgrowth produces gas – Infographic – Amy Myers MD® How SIBO, or small intestinal bacterial overgrowth produces gas - Infographic - Amy Myers MD® https://www.amymyersmd.com/article/sibo-small-intestinal-bacterial-overgrowth-symptoms/ How SIBO, or small intestinal bacterial overgrowth produces gas – Infographic – Amy Myers MD®

Your gut is naturally lined with mucus that lubricates and protects it. However, an overgrowth of bacteria can damage your gut’s mucosal lining. Damaged mucus creates an opportunity for bacterial biofilms — or groups of microorganisms that are protected by a layer of protective slime — to attach to your cell wall, making them harder to control.

As the group of bacteria thrive and feed off of undigested food in your small intestine, the carbohydrates ferment and produce hydrogen. Hydrogen can feed single-celled organisms in your small bowel called archaea, which then produce methane. With Small Intestinal Bacterial Overgrowth, an excess amount of hydrogen, methane, or both can occur in your digestive system.

The excess gas in your GI tract can lead to SIBO symptoms such as gas and severe bloating, among others.

10 SIBO Symptoms

As I always say: “too much of a good thing can be a bad thing,” and this is true when it comes to SIBO. Too much good or bad bacterial flora in the small intestine produces a number of gastrointestinal symptoms that interfere with your normal digestive process. SIBO symptoms can range from digestive imbalance to chronic illness and autoimmune conditions. Here are the main SIBO symptoms you might experience:

  1. Gas, Bloating, and Diarrhea
  2. Abdominal Pain or cramping
  3. Constipation (much less common than diarrhea)
  4. Diagnosis of Irritable Bowel Syndrome (IBS) or Inflammatory Bowel Disease (IBD)
  5. Food Intolerances such as gluten, casein, lactose, fructose, and particularly histamine intolerance
  6. Chronic Illnesses such as fibromyalgia, chronic fatigue syndrome, diabetes, neuromuscular disorders, and autoimmune diseases
  7. Vitamin and Mineral Deficiencies, including vitamins A, B12, D, and E
  8. Fat Malabsorption (signified by pale, bulky, and malodorous stools)
  9. Rosacea and other skin rashes
  10. Leaky gut

Because of the many ways SIBO symptoms manifest in different people — sometimes showing no physical signs whatsoever — these symptoms often go undiagnosed. An estimated 6-15% of healthy, asymptomatic people, and roughly 80% of people with IBS, actually suffer from small intestinal bacterial overgrowth.2

What causes the bacterial overgrowth?

After enzymes break down our food, our gut moves the food through our digestive tract from the stomach to the small intestine and to the colon. In a healthy gut, bacteria gets passed through the digestive tract along with food to its final destination in the colon. Unfortunately, risk factors interfere with this process, including:

  • Damaged nerves or muscles in the gut resulting in leftover bacteria in the small intestine. For example, diabetes mellitus and scleroderma can both affect the muscles in the gut, leaving room for SIBO to develop.
  • Physical obstructions in the gut, such as scarring from surgeries or Crohn’s disease and diverticula (tiny pouches that can form in the wall of the small intestine) can collect bacteria instead of passing it on to the colon, where it belongs.
  • Medications that influence or disrupt the normal gut flora including antibiotics3, acid-blocking drugs, and steroids. 
  • A diet high in sugar, refined carbohydrates, alcohol, and other high-carb foods you eat or drink.

How to Test for SIBO

Before I explain the most effective and accurate lab tests for SIBO4, let’s recap the two different types of small intestinal bacterial overgrowth so that you can understand their role in testing.

Hydrogen vs Methane

As I explained earlier, when you have an overgrowth of bacteria in your small intestine, the carbs you eat can ferment before they are broken down. This fermentation process releases hydrogen gas, so people who experience SIBO symptoms such as elevated levels of hydrogen in their GI tract. One of the most effective methods for diagnosing a bacterial overgrowth is testing hydrogen levels in your gut using a breath test.

Methane SIBO

SIBO can also cause an increase in methane levels. As the hydrogen feeds single-cell organisms in your gut called archaea, they produce methane. This can reduce your hydrogen levels which explains why you can have a false negative hydrogen breath test result and still have methane SIBO.

If you have small intestinal bacterial overgrowth and are dealing with constipation as your main SIBO symptom, you likely have methane SIBO.

This is so important because you ideally want your lab testing to identify which type of SIBO you have. They respond differently to different treatment options.

SIBO Lab Testing Options

1. Breath Test

This is certainly the gold standard when it comes to SIBO testing. It is the most accurate and it determines if the SIBO is hydrogen or methane dominant. However, it can be a bit cumbersome.

You need to fast for 12 hours, and breathe into a small balloon to measure baseline levels of hydrogen and methane. Then, you ingest a precise amount of sugar to feed the bacteria and repeat breath samples every 15 minutes for 3 or more hours to see if levels of hydrogen or methane increase.

If your hydrogen levels are high then you likely have hydrogen-dominant SIBO. However, just because one gas is dominant doesn’t mean that only one type of gas is present. You can have both types of gas present, one is just more prevalent.

I recommend the Lactulose Breath Test from Aerodiagnostics.

2. Organix Dysbiosis Test

This functional medicine lab tests the urine for by-products of yeast or bacteria in the small intestine. If your small intestine is housing a yeast or bacterial overgrowth, byproducts will appear in your urine, indicating their presence. This test is much easier for patients and only requires a single urine specimen. Yet, it does not determine whether your SIBO is hydrogen or methane-dominant.

3. Comprehensive Stool Test

This is also a functional medicine lab test looking at the flora of the large intestines. If I see elevated levels of all good bacteria, I suspect SIBO. I often use stool testing to test for multiple gut infections at one time. This is because there were usually multiple, overlapping gut issues such as Candida overgrowth, small intestinal bacterial overgrowth, and parasites.

4. SIBO Symptoms Checklist

Using a patient’s health history, lifestyle factors, and the list of common SIBO symptoms above, I am often able to make a diagnosis by listening to the patient’s symptoms.

3-Step Protocol for Treating SIBO

Treating your SIBO is a 3-step approach that works to eliminate the overgrowth and restore your gut’s natural balance. My SIBO Breakthrough™ Program is a step-by-step process to help you beat small intestinal bacterial overgrowth for good. In it, you find all the information you need to get control over the overgrowth. With the SIBO Breakthrough Program™, not only do you get information, supplements, and a solution, you also get the support you need to take on these three steps. Check out my video on the topic below:

Step 1: Starve the Overgrown Bacteria

The first step is to remove the foods that feed the bacteria in your small intestine including sugar, alcohol, and carbohydrates. Then, there are the usual suspects behind gut-related issues, including bread, cookies, cake, and cocktails, as well as complex carbohydrates such as grains and legumes. Ultimately, your gut breaks these foods down into sugar, which feed the bacteria.

A SIBO diet includes plenty of non-starchy vegetables, leafy greens, lean proteins, and healthy fats, with minimal fruit.

Step 2: Attack the Bacteria

In my clinic I typically used the antibiotics Xifaxan and Neomyacin to attack the bad bacteria. Xifaxan is more effective with hydrogen-dominant SIBO and Neomyacin with methane-dominant SIBO. These antibiotics kill the pathogenic bacteria with the least amount of disruption to the good bacteria in your microbiome.

If starving the overgrowth and attacking the bacteria have little effect on your SIBO symptoms, it could be because a biofilm has formed around the overgrown bacteria, making it more difficult to eliminate. In these cases, I recommend treating bacterial overgrowth with a biofilm disruptor such as Microb Clear®. It is a blend of magnesium caprylate, berberine, and extracts from tribulus, sweet wormwood, barberry, bearberry, and black walnut. These ingredients work to kill off the bacteria naturally.

The ingredients are not as harsh as broad-spectrum prescription antibiotics which can wipe out good and bad bacteria alike. Microb Clear® is a natural and gentle way to support your journey to optimal health.

Step 3: Restore Your Good Bacteria

The final step is to restore the good bacteria in your gut. This will help support a strong immune system, optimal digestion, and nutrient absorption. Moreover, when it comes to SIBO you want to be particularly careful. Certain probiotics can add fuel to the fire and exacerbate your SIBO symptoms.

The Problem with Most Probiotics

When you have an overgrowth of bacteria in your small intestine, it is often lactobacillus or bifidobacterium species. The majority of probiotic supplements contain these species, so using them adds to the bacteria in your small intestine. 

Consequently, one clue that you may have SIBO is that probiotics containing lactobacillus or bifidobacterium exacerbate your symptoms.

Why Soil-Based Probiotics Are Best for SIBO

Soil-based probiotics don’t colonize the small intestine or feed the bacteria already growing there. In short, they do not contain lactobacillus or bifidobacterium strains, yet provide all the benefits of a probiotic.

These steps, supplements, and more can all be found in my SIBO Breakthrough™ Program.

Using this tried and true method, you can combat your SIBO symptoms and take back your health in the long term!



What is the best diet to treat SIBO?

A SIBO diet minimizes fruit intake and includes plenty of non-starchy vegetables, leafy greens, lean proteins, and healthy fats. See my article Can A Semi-Elemental Diet Help You Beat Stubborn SIBO for more info.


When should I get tested for SIBO?

If you have been treated for certain diseases (such as IBS, diabetes, chronic fatigue, fibromyalgia, or another autoimmune disease) and you haven’t experienced much or any relief, I suggest you get tested. If you do have it, treating it is likely to lead to vast improvements in your symptoms.


Can SIBO go away on its own?

SIBO needs to be addressed for it to go away. Removing toxic and inflammatory foods from your diet and taking gut-supporting nutrients will help mitigate your symptoms.

Bottle of Primal Earth Probiotic