%0 Journal Article
%T Performance and Interpretation of Hydrogen and Methane Breath Testing Impact of North American Consensus Guidelines.
%A Pitcher CK
%A Farmer AD
%A Haworth JJ
%A Treadway S
%A Hobson AR
%J Dig Dis Sci
%V 67
%N 12
%D 12 2022
%M 35366119
%F 3.487
%R 10.1007/s10620-022-07487-8
%X Hydrogen and methane breath tests (HMBT) are widely used clinical investigations but lack standardization. To address this, the North American Consensus (NAC) group published evidence-based recommendations for HMBT.<BR>To evaluate results obtained using NAC recommendations for HMBT, compared to retrospective data that utilized guidelines previously recommended.<BR>HMBT data from 725 patients referred for small intestinal bacterial overgrowth (SIBO) and/or carbohydrate malabsorption (CM) testing were analyzed. Data were compared regarding dose of substrate for SIBO testing (16 vs. 10 g lactulose, and 50 vs. 75 g glucose) and the effect of post-ingestion sampling period for malabsorption testing. The effect of different recommended cut-off values for SIBO were examined.<BR>Substrate dose did not affect methane production. 10 g lactulose significantly reduced positive SIBO results compared to 16 g lactulose (42 vs. 53%, p = 0.04). 75 g glucose significantly increased positive results compared to 50 g glucose (36 vs. 22%, p = 0.04). Provoked symptoms were significantly more prevalent in patients testing positive by both North American Consensus and Ledochowski cut-off values. 34.5% of patients tested positive for CM at 180-min compared to 28% at 120-min (not significant, p = 0.19).<BR>10 g lactulose substrate produces fewer positive SIBO results than 16 g lactulose, while 75 g glucose dose produces more positive SIBO results than 50 g. Performing CM breath tests for 180 min increases number of positive results when compared to 120 min. SIBO cut-off timings require further investigation, but our findings broadly support the NAC recommendations for SIBO and CM testing.