By Dr. Victoria Nguyen
What is SIBO? SIBO is an acronym for small intestinal bacterial overgrowth. Bacteria in our gut is normal and plays an important role for healthy digestion and can even have an influence on other aspects of our health. Normally, the bacteria in our gut help to breakdown fibers to smaller components that the cells of our digestive tract can absorb and utilize for fuel and energy. The gut bacteria also help produce some vitamins that we can use. Most of the bacteria are in the colon, so when there is bacterial overgrowth in the small intestine, it can cause a variety of symptoms. Those symptoms can range from abdominal pain or discomfort, gas, bloating, fatigue, body aches or weakness. If the overgrowth is not addressed, it can lead to other issues such as malabsorption and nutritional deficiencies that could lead to weight loss. Because these symptoms are so vague, it can be difficult to diagnose SIBO from other digestive disorders.
There are a variety of reasons why a person may develop SIBO. Ranging from structural differences to medications to metabolic disorders to past infections or chronic illnesses. Changes in the digestion that commonly increase a person’s risk of developing SIBO is decreased stomach acid production and decreased motility or digestion. Our stomachs normally produce acid to help break down our food and inhibit the growth of bacteria that we might consume. As we get older, our ability to produce stomach acid can decline. The overuse of common medications to treat heartburn often work by decreasing the production of acid and long term use of these medications might put a person at risk for developing SIBO. The normal movement of the digestive tract helps to move the bacteria through towards the colon. Therefore, slowed movement and transition of food through the digestive tract can also increase the time that food is able to be fermented by the bacteria and allow for their overgrowth. Metabolic disorders such as hypothyroidism and diabetes can alter digestion and if not properly managed can predispose SIBO. The immune system in our gut is one of our first lines of protection from the outside world. When someone has lots of digestive infections or has lots of digestive inflammation, it can increase change for someone to develop SIBO.
SIBO is clinically diagnosed by one of two methods – breath test or bacterial culture. Culturing bacteria from aspirate from the small intestine requires endoscopy to obtain. This is a bit more of an invasive procedure and has some problems. Breath tests are commonly used and is a method of indirectly measuring potential overgrowth. These tests require patients to follow a specific diet over 1-2 days and at least 12 hours of fasting prior to collection. The idea of the prep is to starve the bacteria to get more accurate results and reduce the chance of getting a false positive result. The patient will then collect a baseline breath, then consume the substrate solution and collect several breath samples after consumption of the solution. The substrate solution provides a carbohydrate that is easily metabolized by the bacteria. When the bacteria metabolizes this substrate, it can be picked up on your breath during exhalation which is what the breath test uses to measure levels that may be normal or if they are high, may suggest that there is bacterial overgrowth.
There are a variety of therapies that are employed to treat SIBO that should be patient specific. The first thing to address is the underlying cause of bacterial overgrowth and correcting the overgrowth by using antibiotics, herbs, and/or dietary treatments. In all cases, it is important to optimize digestive function and heal the gut after correcting the overgrowth. Addressing regular bowel habits, evaluating potential dietary triggers that might increase inflammation in the gut are places that I start with most of my patients. If you have digestive issues or just want to optimize digestive function, schedule an appointment for more focused discussion and specific recommendations.