Small Intestinal Bacterial Overgrowth, Part Two: What Diseases Are Associated With It?
In part one of this series, I covered what small intestinal bacterial overgrowth (SIBO) is. This post will concern itself with the diseases it’s associated with. As always, association is not causation so SIBO may be along for the ride and not the initiating cause, or conversely, it might be. It can often be difficult to determine what came first: the SIBO or the illness so keep that in mind as you read this post. However, once SIBO is established, it can initiate a vicious feedback loop that will exacerbate whatever illness you’re dealing with.
In addition, SIBO will compound any nutritional deficiencies you’re suffering from making regaining your health one hell of an uphill struggle if not resolved. Without the foundation of a good diet and the ability to digest it, your health status will remain on very shaky ground.
SIBO is substantially under diagnosed. Many people either don’t seek medical treatment when presented with symptoms or just can’t afford to. Even if you do seek out medical care, many doctors don’t check for it. That was true for me as my physician at Kaiser Permanente never ordered the test and I’m sure this is very common. Unfortunately, many in the medical field are not up to date on the latest research.
Finally, and perhaps most insidiously, someone may have it and be totally asymptomatic or have symptoms outside of the GI tract. A good example of the latter is someone who visits a dermatologist complaining of dry skin or rosacea. The proper digestion of fat, fat-soluble vitamins and other nutrients is essential for healthy skin. If you have SIBO, however, this is not going to happen so you are more apt to receive a prescription for a skin cream rather than a referral to a gastroenterologist.
Just how prevalent is SIBO? It depends on whom you ask, what disease is being discussed and what study they cite as the numbers are all over the place like a drunk walking down the street.
For irritable bowel sufferers, the figures range from 30% to 85%. One study using a lactulose breath test, found SIBO in 78% of IBS patients. Once these patients were treated, 48% became symptom free and happier than Charlie Sheen in a whore house. That’s pretty amazing when you think of how often a doctor tells an IBS patient they don’t know what’s causing their symptoms. I suspect the other 22% were either misdiagnosed due to severe carbohydrate malabsorption with accompanying diarrhea, had a yeast overgrowth or were either gluten intolerant or undiagnosed celiacs.
Another study examining the prevalence of SIBO in fibromyalgia found it to be even higher than in IBS sufferers. For those of you unfamiliar with fibromyalgia, it’s a disease characterized by heightened sensitivity to pain accompanied by debilitating fatigue and joint stiffness. Whereas 84% of the IBS sufferers in this study were found to have positive lactulose breath tests, 100% of the 42 subjects diagnosed with fibromyalgia were positive. Yes, you read that right, 100%. Although the connection between the severity of pain and small gut dysbiosis still needs to be worked out, it seems that E. coli may play a role as rat studies have shown it causes pain sensitivity or hyperalgesia.
Celiac and gluten intolerance are often accompanied by SIBO. Celiac disease is an autoimmune disorder where the brush border of the small intestine is damaged by the body’s immune response to gluten in the diet. It results in serious damage to the finger-like projections (the villi and microvilli) that are responsible for proper digestion and enzyme-hormonal signaling and production. In those with celiac disease who are not experiencing much relief after giving up gluten, the rates for SIBO range from between 9% to 55%. If that’s true for celiacs, can you imagine the prevalence in the hoards of people who are “merely” gluten intolerant?
Those with low stomach acid due to chronic gastritis have increased rates of SIBO. In those suffering from chronic pancreatitis, 30% to 40% have SIBO. A study of cystic fibrosis patients saw rates as high as 56%.
Those with liver cirrhosis have rates exceeding 50%. In a group of asymptomatic, morbidly obese subjects, SIBO was found in about 17% of them.
Those with AIDS and other immune deficiency syndromes are also at higher risk for SIBO.
Those who have had previous stomach and gastric bypass surgery are also at high risk. In one study that tracked the rate of SIBO in those suffering from acute diverticulitis, 53 out of 90 subjects (59%) were found to have it thus complicating their recovery.
It shouldn’t come as much of a surprise that SIBO is also found in patients suffering from Crohn’s disease with rates up to 30%, especially in those who’ve undergone previous surgery.
SIBO is also a problem in those suffering from short bowel syndrome after surgical resection. Because the shortened intestine doesn’t have the length necessary to properly digest food, a lot ends up in the colon where fermentation causes bacteria to multiply and easily migrate into the small intestine.
In those with non-alcoholic fatty liver disease, rates of SIBO of up to 50% have been documented. And in those with liver cirrhosis, rates range between 50% to 60%.
Those who have the autoimmune disorder scleroderma suffer from higher rates than controls. Rates in this population range from between 43% to 56% depending on the study cited. Interestingly, many have no diarrhea or other signs of malabsorption.
In type two diabetics, rates of SIBO range from 28% to 60%. Rates were especially high in those suffering from delayed stomach emptying or gastroparesis.
Other diseases associated with SIBO include rheumatoid arthritis, restless leg syndrome, rosacea and interstitial cystitis (bladder pain syndrome), lymphoma and alcoholism.
Finally, in a study conducted in a small group of elderly subjects aged between 70 to 94 years, SIBO was diagnosed in 90% of them. Yikes! It seems that the pathogens in grandma’s and granddad’s digestive tract are also enjoying the early-bird special!
But keep in mind that because SIBO leads to inflammation and increased intestinal permeability, pretty much any disease that results from inflammation caused by bacterial translocation from the gut can be traced back to it. The inflammation that results can affect every organ of the body. First effects are usually seen in the liver where mice studies have shown bacterial translocation from the gut lumen to be a necessary precondition for the development of both alcoholic and non-alcoholic fatty liver disease.
Metabolic endotoxemia has recently become a large focus of research, especially in regard to the translocation of gram-negative bacterial components called lipopolysaccharides (LPSs) into systemic circulation. These LPSs have been implicated in the initiation of the diseases grouped under the heading of metabolic syndrome: diabetes, obesity and heart disease.
It should be clear from this post that if you have any of these conditions you need to have your doctor check you for small intestinal bacterial overgrowth. And you need to make sure that the breath test you’re given measures both hydrogen and methane as a sizeable minority of the population produces methane instead of hydrogen in the presence of SIBO.
Trying to overcome any of these conditions while grappling with an undiagnosed case of SIBO is going to leave you malnourished, frustrated and potentially very, very ill. I get very frustrated with people who ignore their gastrointestinal complaints or only care about symptom relief. They run off to the nearest drug store to buy this or that potion or pill to relieve their gas, bloating, acid reflux, cramping, constipation, diarrhea–you name it, in order to get some relief.
Look, I get it. I was once one of those people. But the reality is that your gut is trying to tell you that something is not right and ignoring these signals will lead to a whole host of trouble down the line.
And what if your doctor won’t test for small intestinal bacterial overgrowth? Easy, find another doctor that will. Your health is at stake and shouldn’t be held hostage to incompetent medical care unaware of the latest research findings.
In the next post I’ll talk about the many causes of SIBO…
Bures J., Cyrany J., Kohoutova D., et al. (2010) Small intestinal bacterial overgrowth syndrome. World Journal of Gastroenterology, 16(24): 2978-90.
Parodi A., Lauritano E.C., Nardone G., Fontana L., Savarino V., Gasbarrini A. (2009). Small intestinal bacterial overgrowth. Digestive and Liver Disease, (3), 44-49.
Quigley E. M. M., Quera R. (2006). Small Intestinal Bacterial Overgrowth: Roles of Antibiotics, Prebiotics and Probiotics. Gastroenterology, 130: S78-S90.