One condition that is fairly common in my clinic and is starting to get a lot of attention by more practitioners is something called Small Intestinal Bacterial Overgrowth (also known as SIBO). SIBO is essentially a subclinical infection of translocated bacteria from the colon to the ileum (distal small intestine). This can cause a wide variety of signs and symptoms, which depends on severity. Signs and symptoms vary from patient to patient, but the most common are bloating (after meals), abdominal distention, constipation, loose stools (diarrhea), flatulence, belching, abdominal pain/discomfort, fatigue, weakness, steatorrhea (excess fat in stools) and anything else malabsorption related.
Malabsorption is important because that can lead to nutritional deficiencies and the inability for your body to maintain homeostasis. The cause of SIBO can be one or a combination of the following: decrease or absent stomach acid (hypochlorhydria/achlorhydria), significant mucosal immune suppression, alteration to the migrating motor complex (MMC) resulting in decreased intestinal motility (aka constipation), decreased brain-gut axis with decreased activation of vagal motor nucleus resulting in decreased intestinal motility, thyroid dysfunction, and anatomical/structural changes to small intestine/ileocecal valve (ICV). Often times it is a combination of causes, which makes SIBO difficult to diagnose and treat.
Under the Radar
The majority of healthcare practitioners probably have never heard of SIBO. Therefore they aren’t looking for it when trying to figure out what is going on with a particular patient. The gold standard for diagnosis of SIBO is aspiration of the small intestines, however, many patients that walk into my clinic are looking for less invasive options. One alternative is a “breath test” where the patient consumes sugar/carbohydrates and measure the output of hydrogen (H) and methane (CH4) in the patient’s breath at particular time frames. Those time frames are usually every 20 minutes for 3 hours.
The whole concept behind the breath test is that the bacterial overgrowth means that there is extra fermentation of carbohydrates causing hydrogen and methane production in the intestines, and that gas goes in both directions of your digestive tract and is measured through the breath. There are some limitations to the breath test, due to motility rates. A person can be constipated and not have the carbohydrates reach the area of the subclinical infection until after 3 hours. The opposite can be true, where the carbohydrates bypass the subclinical infection to the point where they don’t ferment and causes the hydrogen and methane. Another limitation is that the gas that is produced by the subclinical infection isn’t hydrogen or methane, but is something different like ethane. There are also false positives and false negatives to consider as well.
Indicators of SIBO
The way I determine whether or not a patient has SIBO is based off patient history and a physical exam. Feeling bloated two or three hours after consuming food, particularly carbohydrates, is the most indicative symptom. Other indicative symptoms include constipation and/or diarrhea (loose stools), because certain bacteria in the intestines influence gastric motility in a particular way. Going back to the breath test, hydrogen-producing bacteria are correlated with diarrhea while methane-producing bacteria are correlated with constipation. There is a situation where a person can have both types of bacteria. That patient can have alternating constipation and diarrhea. Certain foods will influence production of one gas more than the other, causing the changes in gastric motility. The change in gastric motility is what I think is the foundation of Irritable Bowel Syndrome (IBS), but that is for a later blog.
As far as the physical exam portion of determining whether a patient has SIBO or not, there are a few things that can help with that determination. The first one is listening (auscultating) to the abdomen with a stethoscope, and determine if there are any abnormal sounds as well as an increase or decrease in bowel sound frequency. The second (which cannot be done before auscultation) is palpating the ileocecal valve (ICV) and small intestine area, which is around McBurney’s point (closer to the umbilicus). If there is a subclinical infection of the small intestines, then more than likely there is going to be some inflammation involved.
When inflammation is involved with SIBO, there could be some pain, temperature changes, swelling/fluid, and tissue rigidity with the small intestines as well as the ICV. Particularly with the ICV, there is often a spasm that causes some pain/discomfort upon palpation. ICV spasms (caused by constipation and food sensitivities) are sometimes misidentified as appendicitis because the spasm is so intense. There are cases of appendicitis where the appendix does not look infected or inflamed and is removed anyways. It is important that if you think you have appendicitis to go to the hospital and get that dealt with appropriately, because appendicitis is responsible for approximately 50,000 deaths per year in the United States.
Another physical exam finding that is unique to certain practitioners deals with muscle testing (applied kinesiology). A bilateral external oblique muscle testing “weakness” is correlated with a musculoskeletal manifestation of SIBO. There’s a lot behind that manifestation, but essentially the neurology from the infection neurologically inhibits the neurons that innervate the external obliques, causing a suboptimal neuronal firing from the brain to the muscle (aka muscle weakness). It is somewhat similar to the psoas and obturator test for appendicitis.
Treatment for SIBO varies between practitioners due to the scopes of their practices and what they are able to do with their license. What I like doing (and have had success with) is a combination of diet and supplementation. A patient will be put on a low Fermentable, Oligo-, Di-, Mono-saccharides And Polyols (FODMAP) diet for 6 weeks. This then limits the intake of foods that could be fermented by the bacteria involved with the SIBO.
The highly fermentable foods typically have a high carbohydrate macronutrient percentage, so the low FODMAP diet essentially excludes people from consuming carbohydrates for 6 weeks. The way the low FODMAP diet helps is by depriving the hydrogen and methane forming bacteria of their favorite food sources, and essentially starves them and allows other bacteria (that don’t like the highly fermentable food) to flourish. If someone is suspected of SIBO, I recommend that person tries to limit those high FODMAP foods after that 6 weeks (potentially will undo progress made with diet).
Supplements to Take
As far as supplementation, supplements that contain berberine and oregano oil will help kill off the pathogenic bacteria (97-100% die off) while not killing off the beneficial bacteria (3-5% die off) in the intestines. The way berberine and oregano oil work is by disrupting the cell membranes of pathogenic bacteria and prevent them from replicating. Berberine and oregano oil can be consumed through food, however, if there is a subclinical infection happening I prefer to use something that is concentrated that will be more effective to deal with that infection. Other practitioners (if it is within their scope of practice) will use antibiotics like rifaximin, however, antibiotics can alter the microflora of the intestines in a negative way and cause dysbiosis.
Berberine and oregano oil have been found to be as effective as rifaximin when treating SIBO, and also shown to help with antibiotic-resistant bacteria as well. The particular supplement(s) I provide to my patients can vary, but it is determined through the applied kinesiology muscle testing previously mentioned.
Probiotics are also recommended for SIBO patients, because there is research coming out daily on how they affect human physiology. The biggest reason why is that will physically take up space in the intestine, which will block the pathogenic bacteria from taking that space and proliferating, and produce metabolites the human host will utilize in their physiology. Probiotics, like with every supplement, need to be high quality, or else that supplement will do more harm than good. One particular aspect with probiotics is making sure the probiotic contains strains (on top of a genus and species) that are researched and shown to be beneficial. For example: some probiotics will just have Lactobacillus acidophilus and that’s it (no strain), while a good probiotic would have Lactobacillus acidophilus NCFM (NCFM being a strain).
Getting the Right Treatment
SIBO if not dealt with a long time, as previously stated, can lead to malabsorption symptoms. That can lead to significant changes in a patient’s bloodwork. If a patient isn’t absorbing enough iron or folate/B12, then can lead to anemia. Using that situation as an example, that patient could get diagnosed by another practitioner with anemia and given a supplement to correct the deficiency. The problem with that is the underlying issue isn’t being dealt with. No matter how much iron/folate/B12 is prescribed the patient cannot absorb and assimilate those cofactors.
Dealing with a complicated condition like SIBO, it is important to go to a practitioner that understands the mechanisms behind SIBO. That way if there are any complications, it can be managed under their supervision.
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