All You Want (and Don’t Want) to Know About SIBO

Denn - bacteria

In a normal, happy, and healthy digestive system, food moves from the stomach into the small intestine where it is digested and absorbed. Afterwards, what is left moves to the large intestine. Our small intestines contain bacteria essential for its function. For example, bacteria facilitates the absorption of nutrients, makes nutrients that the body needs, aids in immune function, and prevents the growth of bad bacteria.

What is SIBO?
A digestive disorder called small intestinal bacterial overgrowth (SIBO) occurs when there is an excessive growth of bacteria in the small intestine. This will prevent the proper digestion of food and absorption of nutrients as well as harm the cells in the lining of the small intestine resulting in a leaky gut.

Typically, the small intestine can prevent SIBO by (1) releasing acid, (2) maintaining the movement of its muscular walls, and (3) by prohibiting bacteria from moving into the small intestine by the presence of a valve between the small and large intestine. However, when the valve fails and bacteria from the large intestine enters the small intestine, the intestinal motility slows down due to nerve or muscular damage, or other causes, SIBO can occur resulting in a range of symptoms. This may be further complicated because SIBO can be linked to other intestinal diseases, including irritable bowel syndrome (IBS), diverticulitis, Crohn’s disease, and celiac disease, to name a few.

Patients with SIBO can suffer from indigestion, diarrhea or constipation (less often), abdominal pain, abdominal cramping, bloating and distension, excess gas, body aches, nausea, vomiting, fatigue, weight loss, and/or vitamin deficiency (Vitamins A, B12, D, and iron).

Diagnostic Tests:
There are a number of tests to determine whether one has SIBO including blood tests for anemia, electrolyte imbalance, and vitamin deficiencies, as well as small intestinal biopsies, and x-rays. But the hydrogen breath test is the most common diagnostic tool.

A hydrogen breath test entails breathing into a device that measures the gases hydrogen and methane to provide a baseline, drinking a sugar cocktail, usually lactulose or glucose after fasting for 8-12 hours, and then breathing into the device every fifteen minutes for about three hours. I had to do this and my recommendation is to bring a good book, a sweater in case the room is cold (which I find hospitals typically are), and wear some comfy clothes. The health practitioners are looking for the presence of the gases methane or hydrogen produced by the bacteria to determine if you have SIBO.

Current treatment options are antibiotics (some are Augmentin, Xifaxan, and Cipro), probiotics, or both, drugs that can quicken the muscular movement of the intestine, and/or eating a diet of low carb and low fructose with little refined flours, sugars, and alcohol. Patients may be on antibiotics for 1-2 weeks but there is a risk that the SIBO may occur again so repeated rounds of antibiotics is a possibility. Treating any other associated illness, such as Crohn’s, and eating a proper diet, is the best way to try and prevent SIBO from returning. Physicians may also treat the vitamin deficiency and possible malnutrition through diet and vitamin supplements.

SIBO is difficult to diagnose because unfortunately, some physicians are not aware of SIBO or they misdiagnose their patients with IBS. SIBO is not a fun intestinal disease but the more you know when you meet with your physician can help in you feeling better and getting your life back.

1. Diet to Cure SIBO. Dr. Andrew Weil
2. Digestive Disorders.  WebMD
3. Nutritional Consequences of Small Intestinal Bacterial Overgrowth. John K. DiBaise. Nutrition Issues in Gastroenterology, Series #69
4. Small Bowel Bacterial Overgrowth. MedlinePlus: National Institute of Health
5. Small Intestinal Bacterial Overgrowth: A Comprehensive Review. Andrew C. Dukowicz, Brian E. Lacy, and Gary M. Levine. Gastroenterol Hepatol (N Y). 2007 Feb; 3(2): 112–122
6. SIBO—What causes it and why it’s so hard to treat. Chris Kesser. Guest post by Dr. Amy Nett

Photo taken by Denise Chan on Flickr


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