Charlotte K Pitcher1, Adam D Farmer2,3,4,5, Jordan J Haworth1, Sam Treadway2, Anthony R Hobson6,7. 1. Functional Gut Diagnostics, Manchester, UK. 2. The Functional Gut Clinic, 22 Upper Wimpole Street, London, UK. 3. Institute of Applied Clinical Sciences, Keele University, Staffordshire, UK. 4. Neurogastroenterology Group, Centre for Neuroscience and Trauma, Blizard Institute, Wingate Institute of Neurogastroenterology, Barts and the London School of Medicine & Dentistry, Queen Mary University of London, London, UK. 5. Department of Gastroenterology, University Hospitals of North Midlands, Stoke on Trent, UK. 6. Functional Gut Diagnostics, Manchester, UK. anthony@thefunctionalgutclinic.com. 7. The Functional Gut Clinic, 22 Upper Wimpole Street, London, UK. anthony@thefunctionalgutclinic.com.
Abstract
BACKGROUND: 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. AIMS: To evaluate results obtained using NAC recommendations for HMBT, compared to retrospective data that utilized guidelines previously recommended. METHODS: 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. RESULTS: 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). CONCLUSIONS AND INFERENCES: 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.
BACKGROUND: 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. AIMS: To evaluate results obtained using NAC recommendations for HMBT, compared to retrospective data that utilized guidelines previously recommended. METHODS: 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. RESULTS: 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). CONCLUSIONS AND INFERENCES: 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.
Authors: Jan Tack; Vincenzo Stanghellini; Fermín Mearin; Yan Yiannakou; Peter Layer; Benoit Coffin; Magnus Simren; Jonathan Mackinnon; Gwen Wiseman; Anne Marciniak Journal: BMC Gastroenterol Date: 2019-05-07 Impact factor: 3.067