Understanding SIBO
What is SIBO?
SIBO, short for small intestinal bacterial overgrowth, is characterized by the atypical growth of bacteria in the small intestine. While the large intestine typically has high levels of bacteria, the small intestine should be virtually free of bacteria by comparison. Many of the bacteria that cause SIBO are common in the large intestine, but when food motility (how food is moved through the GI tract) is too slow, these bacteria are then able to multiply into the small intestine. When bacteria is present in the small intestine due to SIBO, it can interact with certain dietary carbohydrates and ferment these sugars into gas, wreaking havoc on a person’s digestive system.
The most common symptom of SIBO is extreme bloating. This is often accompanied by other non-specific symptoms such as gas, heartburn/reflux, abdominal pain, abdominal distention, and nausea. These symptoms are common to many other conditions, which can make it difficult to diagnose SIBO without the proper diagnostic testing.
SIBO results in the production of two gases: hydrogen and methane. Excess hydrogen production is the most common form of SIBO, and the levels of hydrogen measured can get very high in certain people, resulting in the host of SIBO symptoms listed above. The second most most common form of gas production from SIBO is methane, which is associated with constipation and slow bowels. Methane gas is thought to disrupt motility in the small and large intestines.
What causes SIBO?
While SIBO can have many causes, there are two primary culprits: structural and functional issues in the gut. Structural blockages in the gut decreases how quickly substances move through the large and small intestines, which increases the likelihood of developing SIBO. Common structural blockages include scar tissue from abdominal surgery and hernias. Functional issues in the gut, such as food poisoning, also decrease the rate at which food substances move through the digestive tract and can result in SIBO.
How is SIBO Diagnosed?
SIBO is diagnosed using a SIBO breath test. Breath testing is an indirect way of measuring SIBO, as it looks for the presence of hydrogen rather than testing the small intestine directly for the presence of bacteria (direct testing of hte small intestine would be quite invasive, not to mention expensive). A SIBO breath test looks for the presence of hydrogen, which is produced when carbohydrates ferment in the digestive tract due to SIBO (Center for SIBO Testing, 2017). To complete a SIBO breath test, patients do 24-48 hours of dietary preparation, wherein patients only consume specific foods and drinks to create a good baseline for subsequent testing. patients must then fast for 12 hours prior to starting the test, then they collect a baseline breath test sample before mixing a sugar substrate (most commonly lactulose) with water and drinking it. For patients who do have SIBO, the presence of lactulose will cause fermentation in the gut, thus producing hydrogen gas (Center for SIBO Testing, 2017). Once the water/lactulose solution has been consumed, patients will continue to collect breath samples at specific intervals for several hours, and the test kit can then be sealed and mailed to the lab.
Treating SIBO
Treatments for SIBO are often multifaceted, combining medications, herbs, stress management, and in some cases vagal regulation techniques. As always, treatment protocol is varied to meet the unique needs of each patient. If you’re experiencing symptoms that align with what you’ve read here, schedule a visit with our GI specialist Dr. Tiffany Althaus.
Reference
Center for SIBO Testing. (2017, February 19). About hydrogen and methane breath testing. Center for SIBO Testing. Retrieved February 13, 2023, from https://centerforsibotesting.com/about-hydrogen-and-methane-breath-testing/