Posted on: May 5, 2016 at 5:31 am
Last updated: September 21, 2016 at 1:32 pm

This great guest post was written by Brett Hawes, CNP. I encourage you to go check out his website!

Anatomically, the small intestine is roughly 20 feet long, joined to the stomach on the upper end, and connected to the large intestine (colon) on the lower end via the ileo-cecal valve.

While the entire GI tract is normally populated by a wide variety of bacterial species, the type of bacteria in the small intestine is different from those found in the colon.

There is also a relatively small amount of bacteria in the small intestine compared to the colon; about 10, 000 times less. SIBO is a condition where there is an increase in the number of; and/or changes to the type of bacteria in the small intestine.

These are bacteria that usually gravitate up the GI tract from the colon and it is typically more than one type of bacteria involved.

What causes SIBO?

It is difficult to attribute one sole cause in any case of SIBO. There are usually a number of factors involved. The body has numerous complex mechanisms for preventing SIBO, some of which involve digestion, the immune system, and physical structure of the gut.

In addition to breaking down food and ionizing minerals, gastric acid (also known as hydrochloric acid/stomach acid) is also involved with sterilizing pathogens from food.


When gastric acid is low, pathogenic bacteria do not get sterilized. They can then bypass the stomach and take up residence in the small intestine where they may grow uncontrollably. Low gastric acid also has a knock-on effect when it comes to digestion in the small intestine.

Food will not be digested properly and the resultant fermentation and undigested food particles can feed pathogenic bacteria.  

70% of the immune system is in the gut, moderated by our friendly bacteria (probiotics). They prevent pathogenic bacteria from growing in the small intestine by essentially crowding them out. We also have something called Peyer’s patches which secrete immune cells such as T and B-lymphocytes.

These immune cells (plus others) destroy foreign invaders and keep food allergens in check. Excess sugar and alcohol consumption, poor food combining (sweets and concentrated proteins together causing fermentation), antibiotics, birth control pills, and food allergies, sensitivities and intolerances can all wreak havoc on the intestinal immune system.

Structurally, the ileo-cecal valve prevents colonic contents from entering the small intestine. In some cases ileo-cecal valve dysfunction can cause bacteria from the colon to travel back up into the small intestine, causing SIBO. Constipation and excessive straining with bowel movements can weaken this valve leading to dysfunction.

What are the most common symptoms?

Symptoms are non-specific and someone suffering from SIBO may have one or more of the following:

  • Abdominal pain/discomfort
  • Bloating  
  • Abdominal distension  
  • Diarrhea
  • Frothy stool with undigested fats
  • Flatulence  
  • Weakness

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SIBO may also inadvertently lead to malabsorption syndrome, nutrient deficiencies, fat maldigestion and metabolic disorders, but it is clinically very difficult to properly assess these as ‘cause and effect’.

What tests are there to detect SIBO?

There are a handful of tests to detect SIBO with some pros and cons for each. Anaerobic and aerobic colony counts of small intestinal contents are the most accurate but they are also the most invasive, expensive and difficult to perform.

Breath testing is now the most common method to evaluate patients for potential overgrowth because of its simplicity, safety, and lack of invasiveness. Breath tests all rely on the modification of a compound (substrate) by bacteria. The substrates most commonly used are carbohydrate, such as lactulose, glucose, sucrose, or xylose.

When the bad bacteria react with these substrates, they secrete hydrogen and methane. The amounts of these are then measured and used as a diagnostic. Common names for these tests include hydrogen/methane breath test.

Organic acid testing is a test I use most often in my practice. While it not exclusive to SIBO, it is an accurate assessment of overall pathogenic bacteria in the GI tract and can determine whether dysbiosis is present.

It is also a fantastic nutritional test that uncovers certain digestive issues, nutrient deficiencies, liver detoxification pathways and more.


Health Conditions associated with SIBO

Many people walking around out there have no idea that seemingly unrelated illnesses have their origins in the gut; particularly SIBO. We should be clear that while SIBO might not be the sole cause of the following health conditions, it should also not be ruled out:

  • Autoimmune disease (Hashimoto’s, lupus, MS, type 1 diabetes). Note: the mechanisms for these are not clearly understood and studies have proved inconclusive but SIBO should be considered, especially if the symptoms listed above are present
  • Celiac’s disease – especially the non-responsive type
  • Inflammatory bowel disease – ulcerative colitis, Crohn’s
  • Leaky gut syndrome
  • Irritable bowel syndrome – 80% of IBS cases have SIBO
  • Rheumatoid arthritis
  • Chronic fatigue syndrome
  • Fibromyalgia
  • Acne Rosacea
  • Chronic diarrhea
  • Type 2 diabetes – those diabetics with severe diarrhea
  • Interstitial cystitis
  • Restless leg syndrome

Dietary interventions

Avoiding sugars, refined carbohydrates and alcohol is a good start. The addition of antimicrobial foods such as garlic, ginger, coconut oil, turmeric, honey (not in Candida cases), cabbage and horseradish helps to kill bad bacteria. Virtually all spices will do the same but the real super stars are oregano, thyme, rosemary, neem leaf, sage, and cloves.

The specific carbohydrate diet (SCD) and GAPS diets have proven very successful for SIBO and gut issues in general. Part of the reason is that they are low in carbohydrates and essentially starve the bad bacteria. They also rapidly aid in healing the gut lining (leaky gut is extremely common in moderate to severe SIBO cases).

I cannot overstate the importance of fermented foods. These provide a high number of live probiotic organisms that repopulate the gut with good bacteria. Good choices are sauerkraut, kimchi, kefir, cultured vegetables, tempeh and yoghurt (caution as dairy is a common allergen).

Natural therapy

Treating SIBO can be difficult. One of the biggest challenges is going too hard right of the bat. Sensitive individuals might not be able to tolerate high doses of antimicrobials.


When we kill the bad bacteria too quickly, there is a chance that the toxins they release (known commonly as “die-off”) can re-circulate and make you feel quite ill. Sometimes slow and steady is a good approach.

The following is a general guide of what to include in a treatment protocol:

  1. Support digestion and correct low gastric acid with betaine HCl and pepsin
  2. Broad-spectrum digestive enzymes
  3. Antimicrobial herbs such as oregano oil, olive leaf, grapefruit seed extract, neem leaf and berberine.
  4. Probiotics – The predominant and most important bacteria that reside in the small intestine are the Lactobacillus species. A probiotic formula that is higher in these strains will be more beneficial than bifidum strains. 25 billion organisms minimum. You may have to introduce these slowly.
  5. Alkaline tablets – changes the pH of the small intestine to be more alkaline. This improves enzyme functioning, is favourable to probiotic colonization and is an unfavourable environment for pathogenic bacteria.
  6. A food sensitivity test like the ELISA or ALCAT test is valuable in uncovering hidden food allergens.

Be patient as things take time. It is common to experience more gas and bloating initially but things tend to settle down after a few days. If your case is moderate to severe, it is wise to seek the help of a trained professional.  


Campbell-McBride N. Gut and Psychology Syndrome. Cambridge: Medinform Publishing; 2004.

Nieves R, Jackson RT. Specific carbohydrate diet in treatment of inflammatory bowel disease.Tenn Med. 2004 Sep;97(9):407.

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Brett Hawes
Health Expert
I love empowering others to achieve optimal health and vitality. My mission is to advocate and educate through knowledgeable and trustworthy perspectives on health and wellness. I am your needed push in the right direction and because I am a mom I understand you.We all have legacies to live, kids to raise, and marks to leave on this world. Are you ready for your next level?

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