Selection of a cut-off for high-and low-methane producers using a spot-methane breath test:results from a large north American dataset of hydrogen,methane and carbon dioxide measurements in breath

作     者：Klaus Gottlieb Chenxiong Le Vince Wacher Joe Sliman Christine Cruz Tyler Porter Stephen Carter 

作者机构：Synthetic Biologics Inc.RockvilleMarylandUSA Commonwealth Laboratories LLCSalemMassachusettsUSA 

出 版 物：《Gastroenterology Report》 (胃肠病学报道（英文）)

年 卷 期：2017年第5卷第3期

页      面：193-199,I0001,I0002页

核心收录：

学科分类：08[工学] 0812[工学-计算机科学与技术（可授工学、理学学位）] 

主　　题：breath tests spot-methane breath test diagnostic test small intestinal bacterial overgrowth 

摘      要：Background:Levels of breath methane,together with breath hydrogen,are determined by means of repeated collections of both,following ingestion of a carbohydrate substrate,at 15–20 minutes intervals,until 10 samples have been *** frequent sampling is required to capture a rise of hydrogen emissions,which typically occur later in the test:in contrast,methane levels are typically elevated at *** methane emissions represent the principal objective of the test,a spot methane test(i.e.a single-time-point sample taken after an overnight fast without administration of substrate)may be ***:We analysed 10-sample lactulose breath test data from 11674 consecutive unique subjects who submitted samples to Commonwealth Laboratories(Salem,MA,USA)from sites in all of the states of the USA over a one-year *** North American Consensus(NAC)guidelines criteria for breath testing served as a reference ***:The overall prevalence of methane-positive subjects(by NAC criteria)was 20.4%,based on corrected methane results,and 18.9% based on raw *** our USA dataset,the optimal cut-off level to maximize sensitivity and specificity was4ppm CH4,94.5%[confidence interval(CI):93.5–95.4%]and 95.0%(CI:94.6–95.5%),*** use of a correction factor(CF)(5%CO_(2) as numerator)led to reclassifications CH4-high to CH_(4)-low in 0.7% and CH_(4)-low to CH_(4)-high in 2.1%.Conclusions:A cut-off value for methane at baseline of either≥4 ppm,as in our USA dataset,or≥5 ppm,as described in a single institution study,are both highly accurate in identifying subjects at baseline that would be diagnosed as‘methanepositive’in a 10-sample lactulose breath test for small intestinal bacterial overgrowth.