Have you ever experienced bloating so bad that you can’t button your pants? 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. Even if you don’t experience abdominal swelling to such an extreme, any amount of bloating is not normal — it’s a sign of intestinal inflammation, and it could likely be SIBO. 

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

As the bacteria 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 SIBO, an excess amount of hydrogen, methane, or both can occur in your digestive system.

The excess gas in your GI tract can lead to gas and severe bloating. Symptoms include:

10 SIBO Symptoms

  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 symptoms manifest in different people — sometimes showing no physical signs whatsoever — SIBO often goes 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 diverticuli (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 antibiotics, 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 SIBO, let’s recap the two different types of small intestinal bacterial overgrowth so that you can understand their role in testing.

Hydrogen vs Methane SIBO

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 with SIBO have 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.

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 SIBO.

If you have small intestinal bacterial overgrowth and are dealing with constipation, you likely have methane-producing 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.

Lab Testing Options

1. Breath Test

This is certainly the gold standard when it comes to 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. Symptoms Checklist

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

3-Step Protocol for Treating SIBO

Treating 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.

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

Depending on the dominant gas, 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 you are treating bacterial overgrowth at home, as thousands have done successfully, the protocol is to use 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.

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.

You can read more about soil-based probiotics, such as my Primal Earth Probiotic in my article, here. These steps, supplements, and more can all be found in my SIBO Breakthrough™ Program.

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

Primal Earth Probiotic - promo image - Amy Myers MD

Article Sources

  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2890937/
  2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3099351/pdf/GH-03-112.pdf