Small intestine bacterial overgrowth, or bacterial overgrowth syndrome—also known as SIBO (pronounced see-bow)—is the culprit behind a vast number of digestive disorders. In fact, SIBO is associated with approximately 70 percent of Irritable Bowel Syndrome cases!
Approximately 70 million Americans are living with a digestive disease such as irritable bowel syndrome (IBS), and 74 percent of Americans experience digestive discomforts such as gas, bloating, diarrhea, or abdominal pain. SIBO is likely involved in a lot of these cases.
The small intestine is the section of the digestive tract that connects the stomach to the colon. It is about 20 feet long, and unlike the large intestine, it contains few bacteria. The small intestine is a critical area since it is where the body absorbs most of the nutrients from the foods we eat. As a result, an unhealthy small intestine creates conditions for an unhealthy body.
People with SIBO often notice symptoms from eating such as bloating, abdominal pain, diarrhea, constipation, or a mixture of diarrhea and constipation, as well as gastroesophageal reflux disease and nausea. They may also have food reactions and sensitivities, especially to carbohydrates. And since SIBO affects absorption in the small intestine, there are commonly other symptoms such as brain fog, depression, anxiety, fatigue, and weight loss.
There are three types of gases that bacteria produce with SIBO. These include:
Hydrogen-related SIBO is characterized by abdominal gas and bloating and often bouts of loose stool or diarrhea.
Methane-related SIBO is characterized by abdominal gas and bloating, as well as constipation.
Hydrogen sulfide is characterized by abdominal gas and bloating, as well as foul, rotten egg smelling flatulence, bad breath and/or a bad taste in the mouth, and possibly more severe diarrhea.
SIBO is not technically an infection but the excessive colonizing of certain bacteria in the small intestine. Approximately 66% of SIBO cases are chronic. The common symptom of intestinal gas with SIBO occurs from the bacterial fermentation of carbohydrates. This is why SIBO diets reduce or eliminate certain types of carbohydrates.
One of the leading causes of SIBO is a previous bout of food poisoning. Much of the research completed on the causes of SIBO has been done by Mark Pimental, MD, who has a laboratory research program at Cedars-Sinai. He has found that for some people, food poisoning and other infectious gastroenteritis and diverticulitis are associated with the development of Irritable Bowel Syndrome (IBS). This also results in low-grade inflammation, increased intestinal permeability, and autoimmunity in the gut. As a result, there is poor motility in the small intestine that leads to bacteria moving from the colon into the small intestine. There appears to be a direct association between IBS and SIBO.
Additional root causes of SIBO include the long-term use of Proton Pump Inhibitors (PPIs) such as omeprazole, lansoprazole, rabeprazole, pantoprazole, and esomeprazole. Other causes include people with diseases that affect intestinal muscle motility, such as gastric bypass surgery, Parkinson’s disease, diabetes, celiac disease, and other conditions.
There are two ways to test for SIBO. One includes getting fluid from the small intestine and culturing it. This technique is performed by gastroenterologists and is invasive and expensive. Also, only a small part of the small intestine (jejunum) is tested. The other testing method which is more practical involves collecting breath samples and looking for a rise in the gases associated with SIBO (which I mentioned earlier). The lab we use with patients is Trio-Smart®, which is the only breath test that measures all three gases.
Many different approaches can be used to treat SIBO. Once the type of SIBO is identified with signs, symptoms, and testing, a protocol must be followed closely for several months.
One of the challenges with bacteria involved in SIBO is producing collections of microorganisms that secrete slimy substances known as a biofilm. These biofilms protect the bacteria and make it more difficult for the immune system and treating agents to reach the SIBO bacteria. For some cases, we need to use agents that break down biofilms. Examples include colloidal silver, calcium EDTA, N-acetylcysteine, glutathione, and alpha-lipoic acid.
The most well-studied gut-friendly diet is the low-FODMAP diet (low fermentable oligosaccharide, disaccharide, monosaccharide, and polyols). Short-chain carbohydrates are poorly absorbed in the small intestine. The goal of the low-FODMAP diet is to cut back on, or eliminate, these readily fermentable foods, reducing both SIBO and IBS symptoms. SIBO sufferers should avoid the following high FODMAPs:
Once the patient is doing better by following one or more of the protocols below, they do not have to maintain the low Fodmap diet, which can be hard to sustain long-term for many people.
Several herbal extracts can be effective for treating SIBO. Examples of ones we have found effective include thyme, oregano, lemon balm, sage, berberine, Oregon grape, bilberry, and several Chinese herbs. We use formulas that have published clinical effectiveness.
There are also cases of SIBO where we need to use antibiotics. Examples include Rifaximin and Neomycin. However, if we use these antibiotics, we follow herbal therapy since antibiotic treatment has a high relapse rate.
Since there is such a high prevalence of reduced intestinal motility, people with SIBO prone to constipation require long-term support to keep their small intestinal motility healthy. Natural agents include ginger, artichoke extract, and bitter herbals, such as Swedish Bitters. The daily use of fiber supplements such as psyllium and chia seeds are a good idea.
There is quite a variation in patients with SIBO and their response to probiotics. In recent times we have been using a product called SIBO Wellness. It contains probiotics that promote healthy gut flora, protect the integrity of the small intestine, and help treat SIBO and the toxins associated with SIBO.
Dr. Mark Stengler NMD, MS, is a bestselling author in private practice in Encinitas, California, at the Stengler Center for Integrative Medicine. His newsletter, Dr. Stengler’s Health Breakthroughs, is available at www.markstengler.com and his product line at www.drstengler.com
Takakura W, Pimentel M. Small Intestinal Bacterial Overgrowth and Irritable Bowel Syndrome - An Update. Front Psychiatry. 2020;11:664. Published 2020 Jul 10. doi:10.3389/fpsyt.2020.00664
