H 2-breath testing for small-intestinal bacterial overgrowth

Small intestinal bacterial overgrowth (SIBO) is an intestinal microflora unbalance, which can show a wide clinical spectrum ranging from a mild and unspecific intestinal symptoms to a severe malabsorption syndrome. The culture of jejunal aspirate is considered the gold standard diagnostic test for SIBO, however, glucose and lactulose breath tests (GBT and LBT) are currently used in clinical practice. Among them, GBT seems to have a higher diagnostic accuracy in studies comparing breath tests versus culture. Some conditions, such as hypo-aclorhydria, anatomical abnormalities or gastrointestinal motility failure, may cause SIBO and related malabsorption. In these cases, GBT may be useful in order to establish whether malabsorption is due to SIBO or to the underlying disease. Data about the role played by SIBO in irritable bowel syndrome are still inconclusive, and its search by breath test is not recommended in these patients. ;copy; 2009 Blackwell Publishing Ltd.