What is SIBO?

SIBO or small intestinal bacterial overgrowth is a gut condition where there's excessive growth of bacteria in the small intestine. Unlike the large intestine, the small bowel normally contains relatively few bacteria. If there are too many bacteria in this first part of the gut, they can ferment food too early in the digestive process. This produces gas, inflammation and malabsorption of nutrients, which together cause many of the uncomfortable symptoms linked to SIBO.

In this article, we’ll explain what SIBO is, its main causes, how it’s treated, and why testing is so important.

What causes SIBO?

There are a number of reasons why SIBO can develop. Broadly, we can think of SIBO as being caused by changes in gut motility, reduced gut secretions, altered gut structure or other medical conditions.

• Changes in gut motility – slow movement of food through the digestive system gives bacteria more time to multiply in the small intestine. This can happen in conditions such as irritable bowel syndrome (IBS), diabetes or an underactive thyroid.
• Low stomach acid – acid in the stomach normally acts as a barrier to bacteria. Reduced acid production (for example, from long-term use of acid-suppressing medication) makes bacterial overgrowth more likely.
• Structural changes in the gut – scar tissue, strictures or surgery that alters the small bowel can create areas where bacteria collect and multiply.
• Medical conditions – certain illnesses such as coeliac disease, Crohn’s disease or chronic pancreatitis increase the risk of SIBO by affecting digestion and gut function.

What is the treatment for SIBO?

When it comes to treating SIBO, we're not aiming to eradicate all the bacteria from the small intestine. We just need to gut them back into balance to improve symptoms. As we've discussed, SIBO can have a number of causes so we need to tailor the treatment to the individual. That's why it's recommend to treat SIBO with the help of an expert and we actually include consultations with one of our gut-health experts with our SIBO tests.

In general, there are four complimentary approaches to treating SIBO:

• Treat the underlying cause – if there's a clear contributory factor such as taking antacid medications, an underactive thyroid or coeliac disease, we'd try address this first of all.
• Lifestyle changes – there are some simple lifestyle measures that can improve SIBO symptoms such as managing stress to target the gut-brain axis and regular movement to improve gut motility.
• Diet – there's no one "SIBO diet" but people may find that reducing carbohydrate intake - particularly FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) and high sugar foods - can be helpful. Some people also have specific "trigger foods" which can be avoided.
• Antimicrobial treatment –reducing the bacterial burden in the small intestine is a mainstay of treatment. This can be done with conventional antibiotics such as rifaximin¹ or herbal antimicrobials².

How to test for SIBO?

The symptoms of SIBO — bloating, abdominal pain, diarrhoea or constipation — can be very similar to those of other gut issues such as IBS or coeliac disease. That’s why testing is so important. A SIBO breath test measures hydrogen and methane gas levels in your breath after drinking a sugar solution. This helps determine whether your symptoms are likely due to SIBO or another gut condition.

Get your SIBO symptoms checked with our SIBO test