SIBO – Small Intestine Overgrowth and Treatment with Rifaximin


calendar_today   MAY 13, 2023
SIBO Rifaximin

SIBO (Small Intestinal Bacterial Overgrowth) is a condition where too many bacteria are found in the small intestine.

Usually, the small intestine has few bacteria because it's designed to move food quickly to the large intestine, which has more bacteria. But with SIBO, bacteria from the large intestine can move up into the small intestine and multiply, leading to an overgrowth.

The exact cause of SIBO isn't fully known. However, some factors that might increase the risk of developing SIBO include:

  • Slow bowel movements: If food moves too slowly through the gut, bacteria can settle in the small intestine and multiply.

  • Poor stomach acid production: Stomach acid kills bacteria and thus protects the small intestine.

  • Immune system problems: A weak immune system can make someone more susceptible to overgrowth.

  • Changes in gut bacteria: Changes can lead to certain bacteria multiplying in the small intestine.

  • Gut injuries or surgeries: These can disturb the normal gut function and increase the SIBO risk.

Common symptoms of SIBO

Common symptoms of SIBO vary among people but often include:

  • Bloating
  • Stomach pain
  • Diarrhea
  • Constipation
  • Nausea
  • Burping
  • Lack of appetite
  • Weight loss

Usually, a breath test that measures the concentration of hydrogen and/or methane in the breath is used to diagnose SIBO. 

High levels of these gases suggest overgrowth. Samples from the small intestine can also be tested to identify the bacteria causing the disease.

SIBO treatment aims to decrease bacteria in the small intestine and prevent new growth. 

Treatment can involve antibiotics and probiotics. Antibiotics can help reduce bacteria and relieve symptoms. Probiotics help restore the balance of gut bacteria and prevent new bacterial growth.

Rifaximin and SIBO

Rifaximin is an antibiotic often used to treat SIBO. Unlike many other antibiotics that can kill beneficial gut bacteria, Rifaximin specifically targets bacteria in the small intestine with minimal effect on beneficial bacteria in the large intestine.

A 2010 study published in the journal "Gut" looked at Rifaximin's effects on SIBO patients. 

The results showed that Rifaximin effectively treated SIBO symptoms and significantly reduced hydrogen and methane levels in the breath test.

Another 2014 study in "Digestive and Liver Disease" compared Rifaximin's effectiveness to a placebo in SIBO patients. 

The results showed Rifaximin was significantly more effective than the placebo in reducing SIBO symptoms and improved quality of life.

While Rifaximin is considered safe, it can sometimes cause side effects like diarrhea, stomach pain, and nausea. It's important to understand that Rifaximin might not work for everyone and the choice of antibiotic can vary.

"The results showed Rifaximin was significantly more effective 

than the placebo in reducing SIBO symptoms and improved quality of life"

On the other hand, a diet high in fat, animal protein, and low-fiber carbohydrates is harmful. Artificial sweeteners are especially bad.

They encourage the growth of bacteria that extract more carbohydrates from the food, achieving the exact opposite of their intended purpose, leading to weight gain.

SIBO and Diet

Dietary changes can also help alleviate SIBO symptoms. A low-carbohydrate diet rich in proteins and healthy fats is recommended. This diet can reduce the available food for bacteria in the small intestine, thus limiting bacterial growth.

People with SIBO should avoid certain foods that boost bacterial production in the small intestine, such as sugar, sweets, starchy foods, and alcohol. High-fiber foods like whole grains, legumes, and some vegetables might also cause issues for some people.

In some cases, treating structural issues in the intestine might be necessary. For example, a narrowing or blockage in the small intestine can disrupt its normal function and increase the risk for SIBO. Surgery might be needed to fix these issues.


SIBO treatment is usually long-term. Many patients need repeated courses of antibiotics or probiotic therapies to control bacterial growth in the small intestine. Regular doctor check-ups are also crucial to monitor symptoms and prevent complications.

In summary, SIBO is a common condition with various symptoms. While the exact cause isn't fully known, there are many factors that can increase the risk of developing it. Treatment typically involves antibiotics, probiotics, and dietary changes.

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