Small Bowel Bacterial Overgrowth
(SBBO; Bacterial Overgrowth, Small Bowel; Small Intestine Bacterial Overgrowth; SIBO; Bacterial Overgrowth, Small Intestine)
Small bowel bacterial overgrowth (SBBO) occurs when there is a build-up of too much bacteria in the small bowel.
|The Small Intestines
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SBBO is often caused by an abnormality in the small bowel. Food is not able to flow properly though the intestines. Conditions that may cause this include:
- Birth defect
- Digestive disorders
Factors that may increase your chance of SBBO include:
Other risk factors include:
- An obstruction in the small intestine
- Weakened immune system
- Older age
Any condition that affects how food moves through the small bowel may increase the risk of SBBO.
Your doctor will ask about your symptoms and medical history. A physical exam will be done.
Tests may include
- Breath tests—to analyze certain gases that may be present after fasting and eating specific sugars
- Culture of intestinal fluid (aspirate)—a catheter is used to get a sample of fluid from the small bowel
The goals are to:
- Reduce the levels of harmful bacteria in the small bowel
- Treat the underlying condition
Antibiotics are often prescribed to treat SBBO. Usually treatment is temporary, but in some cases you may need to take antibiotics for a longer period.
To make sure that you get the proper nutrients, you may need to:
- Work with a dietitian
- Follow a special diet, such as a carbohydrate-restricted diet
Take vitamins and/or supplements
In some cases,
is needed with a special formula.
For severe cases, surgery may be needed. This is done to correct an abnormality in the small bowel.
If you have any of the conditions that are linked to SBBO, get proper treatment. This may reduce your chance of having a build-up of bacteria in the small bowel.
American Gastroenterological Association
National Institute of Diabetes and Digestive and Kidney Diseases
Canadian Association of Gastroenterology
Canadian Digestive Health Foundation
Bacterial overgrowth syndrome. Merck Manual Professional Version website. Available at:
http://www.merckmanuals.com/professional/gastrointestinal-disorders/malabsorption-syndromes/bacterial-overgrowth-syndrome. Updated May 2016. Accessed October 3, 2017.
Bures J, Cyrany J, Kohoutova D, et al. Small intestinal bacterial overgrowth syndrome.
World J Gastroenterol.
Lactose and glucose hydrogen breath test. Cleveland Clinic website. Available at:
https://my.clevelandclinic.org/health/articles/lactose-and-glucose-hydrogen-breath-test. Accessed October 3, 2017.
Lin H. Small intestinal bacterial overgrowth.
Short bowel syndrome. EBSCO DynaMed Plus website. Available at:
http://www.dynamed.com/topics/dmp~AN~T115699/Short-bowel-syndrome. Updated May 6, 2014. Accessed October 3, 2017.
Vanderhoof J, Young R, Murray N, Kaufman SS. Treatment strategies for small bowel bacterial overgrowth in short bowel syndrome.
J Pediatr Gastroenterol Nutr.
- Reviewer: EBSCO Medical Review Board
Daus Mahnke, MD
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