Management of small intestinal bacterial overgrowth

Quigley, 2020

Treatment of small intestinal bacterial overgrowth (SIBO) should be initiated by a gastroenterologist—therapy may involve suppression of the bacterial overgrowth with antibiotic therapy, surgical correction of the underlying cause (if possible), and correction of any nutritional deficiencies (eg vitamin B₁₂ deficiency; see Water-soluble vitamin deficiencies).

Note: Treatment of SIBO should only be initiated by a gastroenterologist.

Evidence for antibiotic choice, dose and duration is lacking, so therapy is largely empirical. Rifaximin, a nonabsorbable antibiotic, has demonstrated efficacy in clinical trials but is expensive¹ Quigley, 2020. Other antibiotics used in clinical practice include amoxicillin+clavulanate, cephalosporins, doxycycline, metronidazole and norfloxacin. Duration of antibiotic therapy is generally 7 to 10 days.

SIBO commonly recurs a few months after antibiotic therapy; to reduce the risk of developing resistant organisms, rotating courses of antibiotics are sometimes used by gastroenterologists.

¹ At the time of writing, rifaximin is not approved by the Australian Therapeutic Goods Administration (TGA) for small intestinal bacterial overgrowth. See the TGA website for current information. Rifaximin is available through compounding pharmacies.Return