应用乳果糖氢呼气试验诊断小肠细菌过度孽生综合征

LACTULOSE HYDROGEN BREATH TEST IN SMALL INTESTINAL BACTERLAL OVERGROWTH

与细菌学检查做对照，将乳果糖与稀钡同服，测定了１０例健康志愿者及２１例疑有小肠细菌过度孽生综合征患者的呼气氢含量。以△Ｈ＿２≥１０×１０￣－６、同时钡剂首段仍在第６组小肠以上为诊断标准，建立了简便无创的诊断小肠细菌过度孽生的方法，其敏感性为７１．４％，特异性为８８．２％，准确性为８０．６％。细菌过度孽生组与非细菌过度孽生组空腹氢分别为（２１．５±５．１）×１０￣－６（ｎ＝１４）和（１７．２±１．５）±１０￣－６（ｎ＝１７），其差异有显著性（，Ｐ＜０．０１）。提示空腹氢对诊断小肠细菌过度孽生有一定的临床参考意义。

actulose hydrogen breath test(LHBT ) was evaluated in 21 patients suspected of having small intesti-nal bacterial overgrowth syndrome and 10 healthy volunteers as control.After dietary preparation and a 12-hour fast,subjects received 15g of lactulose mixed with 40%barium sulfate,The purpose of the barium meal was to reveal the position of lactulose in the intestines. End-expiratory samples of breath were taken at 15 minutes intervals at least for 4 hours.Breath hydrogen was measured with gas chromatography.A positive LHBT was defined as increase of hydrogen concentration in the breath more than 10× 10￣-6 above the baseIine value before barium reached the sixth group of small intestine. Cultures were considered posi-tive for bacterial overgrowth when anaerobic counts≥10￣6 CFU/ml of aspirate. The procedure was carried out under sterile condition. Compared with the bacteriologic cuIture,LHBT has a sensitivity of 71.4%,specificity of 88.2%and accuracy of 80.6%,These results show that the LHBT is a simple, non-invasive and relatively reliable method for diagnosis of small intestinal bacterial overgrowth.