Small Intestinal Bacterial Overgrowth (SIBO) is a very common yet often overlooked cause of IBS. According to research, up to 85% of people with IBS test positive for SIBO! So if you’re experiencing bloating, diarrhoea or other symptoms commonly associated with IBS, then you’ll certainly want to consider the question, is it IBS? Or SIBO?
What is SIBO?
In healthy digestive tracts, the small intestine contains <10,000 bacteria per milliliter of fluid, whereas the large intestine (colon) contains 1,000,000,000 bacteria per milliliter of fluid. Therefore, the small intestine contains much less bacteria than the large intestine. This is a good thing because we absorb most of the nutrients from the food we eat in the small intestine so we don’t want bacteria to interfere with this process.
SIBO occurs when there are too many bacteria in the small intestine. SIBO bacteria feed on and ferment the food we eat releasing gas as a byproduct. This interferes with both digestion and absorption of nutrients increasing our risk of developing nutrient deficiencies. SIBO bacteria and their by-products can also damage our intestinal lining resulting in inflammation and a whole host of symptoms.
Common SIBO symptoms:
- Abdominal pain
- Constipation and/or diarrhea
- Brain fog
- Loss of appetite
- Floating, greasy or discolored stools
- Food intolerances and sensitivities
As you can see, there is a huge overlap between typical symptoms of SIBO and the symptoms of IBS.
What causes SIBO?
SIBO is a complex condition that can develop for a number of reasons including (but not limited to):
1 – Insufficient stomach acid production (e.g. from medications like PPI’s, chronic stress, h.pylori, gastric deficit).
Stomach acid helps break down our food and kills ingested bacteria and pathogens. If we don’t have enough, then bacteria can feed on and ferment undigested food particles leading to bacterial proliferation – hello SIBO!
2 – Insufficient digestive enzymes
Digestive enzymes help us to break down our food. If we are not producing enough then food remains in the small intestine allowing bacteria to feed on and proliferate.
3 – Structural abnormalities (e.g. a faulty ileocecal valve)
The ileocecal valve serves as a “gate” between your small and large intestine. When functioning properly, it allows food to flow down through the small intestine and into the large intestine before closing to prevent it from flowing backwards. If this “gate” doesn’t shut when it’s supposed to, then bacteria from the colon can start to migrate up into your small intestine.
4 – Slow gut motility (meaning food doesn’t move through the digestive tract optimally)
We have an internal cleaning mechanism called the Migrating Motor Complex (MMC) which is a distinct pattern of electromechanical activity observed in gastrointestinal smooth muscle during the periods between meals.
The MMC is responsible for sweeping residual undigested food material and bacteria through the digestive system.
If our MMC is absent or disordered then more food particles remain in the small intestine, bacteria then start to feed on and ferment the food leading to increased gas buildup, bloating, constipation and all sorts of other digestive symptoms. Infact, poor MMC function is one of the most common causes of IBS and Small Intestinal Bacterial Overgrowth (SIBO)!
Supporting MMC function may therefore decrease the risk of developing IBS and SIBO and can also help to relieve some of the symptoms of these conditions. Check out my Happy Gut Guide download for MMC support.
5 – Food poisoning
There is a link between SIBO and post-infectious IBS (where IBS symptoms arise after an episode of food poisoning). Infact, 1 in 9 people develop IBS after an episode of food poisoning! Toxins released from the bacteria that cause food poisoning trigger an immune response which in some cases can result in damage to gut nerves and alter MMC function/gut motility. This results in many symptoms associated with IBS and SIBO.
How do I know for sure that my IBS is actually SIBO?
Thankfully we can test for SIBO privately using a hydrogen and methane SIBO breath test which measures the amount of hydrogen and methane gas produced by bacteria in the small intestine. Although this test is the most reliable way of identifying SIBO, it is not 100% perfect. Hence it is important to work with a Registered Nutritional Therapist who will consider your symptoms in conjunction with other clues identified from your medical/health history and test results (e.g. blood, stool and SIBO tests).
Bear in mind that whilst SIBO is a major cause of IBS – it is not the only one. Working to identify and address other possible root causes is a must in order to achieve long term relief.
Can I “get rid” of SIBO?
In short – Yes you can! However, similarly to IBS, there are a number of possible reasons why SIBO developed. A specific antimicrobial protocol can help you eradicate the overgrowth and reduce symptoms but to achieve long-term relief and prevent SIBO relapse, it’s important to address the underlying causes. Tackling SIBO for good requires a multi-pronged approach involving both dietary, supplement, and lifestyle interventions. The specificities of which will vary between individuals.