Our entire GI tract contains bacteria, but the highest concentration of bacteria is found in the colon. Each part of the intestine contains its own type of bacteria.
The small intestine is where the magic happens—that’s where we complete the digestion of our food and take in valuable nutrients. When bacteria migrate from the large intestine and start to colonize the small intestine or if food sits too long in the small intestine, we can develop small intestine bacteria overgrowth, or SIBO. Why is this an issue? Well, the small intestine’s job is to absorb nutrients. If foreign bacteria are present, the small intestine’s ability to absorb those nutrients becomes compromised. This can lead to symptoms such as gas, bloating, diarrhea, cramping, heartburn, nausea, leaky gut, food sensitivities, brain issues, skin issues, etc.
SIBO is so common that Dr. Allison Siebecker, ND, believes that over 60% of cases of IBS (irritable bowel syndrome) are actually chronic SIBO.
Risk factors for SIBO
• Low stomach acid
• Irritable bowel syndrome
• Celiac disease (long-standing)
• Crohn’s disease
• Prior bowel surgery
• Diabetes mellitus (Type 1 and Type 2 diabetes)
• Multiple courses of antibiotics
• Organ system dysfunction, such as liver cirrhosis, chronic pancreatitis, or renal failure
• Heavy alcohol consumption
• Use of hormonal birth control
• Vagus nerve issues
Causes of SIBO
Inflammation of the vagus nerve can affect gut function. In addition, serotonin issues affect gut motility. According to WebMD.com’s Digestive Health Centre, “Normally, the coordinated action of the muscles of the stomach and small intestine propels the food from the stomach, through the small intestine and into the colon. This muscular action also sweeps bacteria out of the small intestine and limits the numbers of bacteria in the small intestine. However, when a condition interferes with the normal activity in the small intestine, this can result in SIBO, by allowing bacteria to stay longer and multiply in the small intestine. The lack of normal muscular activity also may allow bacteria to spread backwards from the colon and into the small intestine.”
Dr. Steven Sandberg-Lewis, ND, believes that the health of our gut lining and mucosal brush borders (which aid absorption) may also have an impact. Pockets called “diverticuli” can create a breeding ground for bacteria, which is why they are removed if uncovered during a colonoscopy.
That’s not all. Your ileocecal valve is a one-way valve leading from the small intestine to the colon. It allows digested foods to pass through and keeps waste materials from flowing back in. If your ileocecal valve isn’t functioning correctly, bacteria can migrate back into the small intestine. Ileocecal valve issues are pretty common. Fortunately, most chiropractors are able to perform a simple in-office adjustment to “unstick” the valve.
Finally, in his blog, the Medical Medium blames SIBO on an unresolved Streptococcus infection. It is well known that pathogens like this one like to hide themselves in biofilms (coatings) to evade detection by our immune system. There are probably many more.
How do you know if you have SIBO?
Dr. Sandberg-Lewis outlines these key indicators of SIBO:
- If you experience GI symptom relief right after taking antibiotics
- If you feel worse taking probiotics especially those with prebiotics
- If fiber makes your GI symptoms worse
- If a gluten-free diet removes your symptoms
- If you develop GI issues after taking antibiotics, PPI, or opiates
- If you have low ferritin or iron stores with no other apparent cause
- If you get post-infection irritable bowel syndrome
An effective way to test for SIBO is by breath testing. This test measures the amount of hydrogen and methane gas being produced by the small intestine and expelled by the lungs. (The test consists of swallowing a sugary solution, then letting it digest for a certain amount of time before exhaling into a tube that measures gas levels.) Cyrex Labs has also has a test called the Irritable Bowel/SIBO Screen as an alternative to the breath test.
All gas is not the same
Have your ever wondered why one person’s gas smells way worse than another’s? SIBO experts believe that people produce different types of gas depending on what kind of bacteria is present in their bodies. In addition, these gases can affect a person’s physiology quite differently.
For instance, methane gas may lead to constipation, whereas hydrogen gas is associated with diarrhea. Dr. Vincent Pedre, author of Happy Gut, states that methane is produced by non-bacterial pathogens that can negatively affect peristalsis or movement through the GI tract (which leads to constipation). On the other hand, hydrogen gas is produced by bacteria that ferment carbohydrates in the small intestine. This produces toxins which increase osmolarity and peristalsis (i.e., diarrhea) as a defensive mechanism to get this stuff out of the body.
So how is SIBO treated?
The type of gas present directs the treatment approach. Methane-caused SIBO is much more difficult to treat than hydrogen-caused SIBO, so much so that the methane version has actually been called “pissed-off methanogen syndrome.” The organisms that create methane may not even be a bacteria at all, but something call archaea which is more difficult to eradicate.
SIBO treatment is approached from two angles: diet and either prescription or herbal antibiotics. Dr. Siebecker points out that the clinical dietary success rate in SIBO is anywhere from 60% to 95% but up to 91% when diet is addressed in conjunction with antibiotics.
For methane-based SIBO, allicin—a compound found in garlic—has been found to be affective, whereas hydrogen-based SIBO might be better treated with whole garlic, berberine, neem, cinnamon, etc. For both types of SIBO, I often recommend a biofilm buster to make sure you are eradicating underlying colonies that may be hiding out in the biofilm as well as vitamin A to help the gut’s immune system.
Probiotics may or may not be indicated as we may not want to increase bacteria counts especially in hydrogen-based SIBO. But Dr. Pedre states that “If it is a methane-predominant [SIBO] and it is probably more archaea, they will, more likely, do well with fermented foods. It’s not going to worsen their symptoms. It actually will help them get better. We need the lactobacillus to out-compete the archaea to keep it in control.”
By following a specific diet, you can reduce the amount of fermentable material in your gut that feed bacteria. An individual’s success will vary greatly based on his or her ability to process certain foods. The specific carbohydrate diet (SCD), low FODMAP diet, SIBO food guide (see Allison Siebecker, ND), Cedars-Sinai low fermentation diet, and elemental diets have all been found to be effective because they all reduce certain sources of carbohydrates. You can read about some of these diets in the appendix.
Keep in mind that these methods may not treat the underlying cause—that is often structural. It’s very important that you see a licensed doctor to rule out any underlying issues to prevent yourself from relapsing after your SIBO treatment. And as always, practice those vagus nerve exercises!
It is also important to mention that bacterial “die-off” is common with both dietary and antibiotic approaches, so you may feel much worse before you get better. Don’t give up too early on the protocol if you feel that it isn’t working for you—it may just take some time for the die-off phase to end.