应用LGR二氧化碳同位素分析仪诊断小肠细菌过度生长程度

LGR 二氧化碳同位素分析仪最新应用：

应用LGR二氧化碳同位素分析仪，通过测定肠易激综合症患者的呼出气体中的¹³CO_2和¹²CO₂的同位素分子比率，可以对患者体内小肠细菌过度生长情况做出正确诊断

Gourab D. Banik,^a   Abhijit Maity,^a   Suman Som,^a  Chiranjit Ghosh,^a   Sunil B. Daschakraborty,^b   Sujit Chaudhuri,^b  Shibendu Ghosh^c and   Manik Pradhan*^ad  

Hydrogen breath tests (HBT) are widely used for the diagnosis of small intestinal bacterial overgrowth (SIBO) in patients with irritable bowel syndrome (IBS). However, the conclusions drawn from these studies are highly controversial, and several discrepancies exist in the results. The aim of our study is to develop an alternative ¹³C-glucose breath test (¹³C-GBT) methodology by measuring high-precision ¹³CO₂/¹²CO₂ isotope ratios in exhaled breath to accurately diagnose SIBO using an optical cavity-enhanced CO₂ isotope analyzer. In all, 118 diarrhea-predominant (IBS-D) patients diagnosed according to ROME III criteria underwent¹³C-GBT and HBT following the ingestion of a test meal containing 50 mg ¹³C-enriched glucose with 50 g glucose. The excretion of ¹³CO₂ enrichments and a cumulative percentage dose of ¹³C-recovered (c-PDR) significantly depleted (p < 0.001) for the positive SIBO patients (n = 25) compared to the patients with negative SIBO (n = 53) as diagnosed by HBT. A cut-off value of 5.47‰ at 45 min was indicative of a positive SIBO syndrome. Subsequently, a portion of IBS-D individuals (n = 20) whose HBTs were negative but ¹³C-GBTs were positive, suggesting HBT often fails to diagnose SIBO when the patients may have “non-hydrogen-producing” bacteria. ¹³C-GBT also correctly diagnosed SIBO in patients (n = 20) within the “grey-zone” and during the preclinical phase of SIBO as opposed to HBT. The prevalence of SIBO with IBS-D in Indian population was estimated to be 45.7%. Our study demonstrates ¹³C-GBT, for the first time, as a clinically valid and sufficiently robust alternative diagnostic methodology for an accurate evaluation of SIBO in IBS-D patients and superior to HBT.

文章链接：http://pubs.rsc.org/en/content/articlelanding/2014/ja/c4ja00186a#!divAbstract