Small intestinal bacterial overgrowth, intestinal permeability, and non-alcoholic steatohepatitis

Conversely, a single rise in breath hydrogen levels commencing before the test meal reached the caecum was evident in 22% of subjects with culture proven SIBO. [...]both false positive and false negative diagnoses of SIBO may result. 2 Indeed, as pointed out in the accompanying commentary (Gut 2001;48: 148-9 ), the prevalence of SIBO, as diagnosed by breath testing, in control subjects in Wigg et al's study seems remarkably high. Smaller bacterial concentrations only are required for the catabolism of 14C- d -xylose to 14CO2. [...]in SIBO, catabolism of 14C- d -xylose by small intestinal bacteria will result in an early 14CO2 peak prior to the colonic H2 and CH4 peaks.