Small Intestinal Bacterial Overgrowth (SIBO) Testing

What SIBO Is

In SIBO, normal commensal bacteria in the large and small intestines overgrow in the small intestine, fermenting carbohydrates from food producing gas and toxins. This can lead to painful, stuck gas and bloating anywhere from 20 minutes to 1½ hours after meals. SIBO irritates the lining of the small intestine, where most nutrients are absorbed, and can contribute to malabsorption, inflammation, and damage to the gut lining.

Common Symptoms

  • Bloating, especially after meals
  • Trapped gas and belching
  • Abdominal pain or discomfort
  • Diarrhea, constipation, or both
  • Nausea
  • Heartburn or acid reflux
  • Fatigue
  • Nutrient deficiencies
  • Weight gain

SIBO is described in the source material as the most common underlying cause of IBS, or irritable bowel syndrome.

Causes and Risk Factors

  • Food poisoning (post-infectious IBS)
  • Hypothyroidism
  • Dysbiosis (gut flora imbalance)
  • Chronic stress and anxiety
  • Scar tissue from abdominal surgery
  • Traumatic brain injury
  • Crohn’s disease
  • Use of PPIs or antibiotics

Diagnosis

SIBO is diagnosed using a lactulose or glucose breath test. Lactulose is often preferred because it travels through the small intestine and allows assessment of gas production along its length. Glucose, on the other hand, is absorbed in the upper small intestine and may not reach the distal small intestine, potentially missing cases of SIBO in that region.

Before testing, patients follow a specific preparation diet for 1–2 days to help improve test accuracy. Dr. King provides a convenient at-home test kit.

On the day of the test, you drink a lactulose solution and collect breath samples every 20 minutes over a three-hour period. The test measures three gases: hydrogen, methane, and hydrogen sulfide. Reputable laboratories also measure carbon dioxide to verify that each sample contains enough exhaled air.

Elevated levels of these gases may indicate an overgrowth of gas-producing microorganisms in the small intestine. The results help identify the type of overgrowth and guide treatment.

Treatment

SIBO is often associated with an underlying imbalance, so effective treatment involves more than simply reducing bacterial overgrowth. Although antimicrobial therapies and a low-FODMAP diet may help reduce symptoms, they may not address the factors contributing to the condition.

Dr. King focuses on identifying and addressing potential underlying contributors, which may include intestinal dysbiosis, thyroid dysfunction, stress, anxiety, or a history of food poisoning. By supporting the body’s underlying systems and addressing contributing factors, the goal is to promote lasting improvement and reduce the likelihood of recurrence.

Next step  For current clients or a free 15-minute consultation

Similar Posts