Diagnosis and management of small intestinal bacterial overgrowth

Nutr Clin Pract. 2013 Jun;28(3):289-99. doi: 10.1177/0884533613485882. Epub 2013 Apr 24.


Small intestinal bacterial overgrowth (SIBO) can result from failure of the gastric acid barrier, failure of small intestinal motility, anatomic alterations, or impairment of systemic and local immunity. The current accepted criteria for the diagnosis of SIBO is the presence of coliform bacteria isolated from the proximal jejunum with >10(5) colony-forming units/mL. A major concern with luminal aspiration is that it is only one random sampling of the small intestine and may not always be representative of the underlying microbiota. A new approach to examine the underlying microbiota uses rapid molecular sequencing, but its clinical utilization is still under active investigation. Clinical manifestations of SIBO are variable and include bloating, flatulence, abdominal distention, abdominal pain, and diarrhea. Severe cases may present with nutrition deficiencies due to malabsorption of micro- and macronutrients. The current management strategies for SIBO center on identifying and correcting underlying causes, addressing nutrition deficiencies, and judicious utilization of antibiotics to treat symptomatic SIBO.

Keywords: FODMAP; bacteria; intestine, small; metagenome; microbiota; small intestinal bacterial overgrowth.

Publication types

  • Review

MeSH terms

  • Abdominal Pain / drug therapy
  • Abdominal Pain / microbiology
  • Anti-Bacterial Agents / therapeutic use
  • Bacterial Infections / diagnosis*
  • Bacterial Infections / drug therapy
  • Breath Tests
  • Diarrhea / drug therapy
  • Diarrhea / microbiology
  • Flatulence / drug therapy
  • Flatulence / microbiology
  • Gastrointestinal Motility
  • Gram-Negative Bacteria
  • Humans
  • Irritable Bowel Syndrome / diagnosis*
  • Irritable Bowel Syndrome / drug therapy
  • Irritable Bowel Syndrome / microbiology*
  • Jejunum / microbiology*
  • Microbiota


  • Anti-Bacterial Agents