第一届全国呼气试验临床应用与研究交流会征文通知

全国呼气试验研究会定于２０００年１０月在江苏苏州市召开“第一届全国呼气试验临床应用与研究交流会”。现将有关事项通知如下：一、征文内容（一）呼气氢试验在胃酸分析、吸收不良症、小肠细菌过度生长、胃肠动力学、药代动力学与临床营养等方面的研究与临床应用；（二）１３Ｃ呼气试验、１４Ｃ呼气试验在吸收不良症、肝功能与幽门螺杆菌方面的诊断与应用。（三）胃、肠疾病的研究新进展。二、征文要求（一）论文全文及中、英文摘要（５００字或单词以内）一式两份。格式按中华消化杂志样式要求（目的、方法、结果及结论）并以电脑打…     

13C-呼气试验评估胰腺外分泌功能的临床应用

三酰甘油、蛋白质和淀粉均可作为13C-呼气试验的底物，用于检测胰腺外分泌功能。目前研究最多的是13C-三酰甘油呼气试验，其中以13C-混合三酰甘油呼气试验（MTG—BT）最具优势。N-苯甲酰-L-酪胺酰-【1-13C】丙氨酸（Bz—Tyr—Ala）呼气试验无需试餐，近年逐渐受到关注。13C-淀粉呼气试验影响因素较多，研究近况不甚理想。本文对各类，13C-呼气试验的底物特点及其评估胰腺外分泌功能的临床应用作一综述。     

呼气流速受限在儿童支气管哮喘气道反应性评价中的应用

自2004年开始我们进行了呼气相气道内负压（NEP）检测呼气流速受限的系列研究^[1-3]，初步证实NEP法检测呼气流速受限能作为评估慢性阻塞性肺疾病（COPD）、支气管哮喘（简称哮喘）患者病情和呼吸困难严重程度的简单、有效方法，并可应用于支气管舒张试验作为评估气道阻塞可逆性的判断指标。但目前有关NEP法检测呼气流速受限在支气管激发试验中的可行性尚不明确，为此，我们探讨NEP法检测呼气流速受限作为儿童支气管激发试验判断指标的可行性。     

血清学与呼气试验结合监测治疗幽门螺杆菌感染的疗效

为评价血清学及（１４）￣Ｃ－尿素呼气试验在治疗幽门螺杆菌（Ｈｐ）感染疗效监测价值，本研究中第一阶段对４２例Ｈｐ感染，患者在抗Ｈｐ治疗前、停药１、３、６、１２个月同期进行胃镜检查、（１４）￣Ｃ－尿素呼气试验及血清ＨｐＩｇＧ抗体测定。分析患者停药１年内随访期呼气试验及血清学变化规律，制定出以呼气试验高于界限值、血清学吸光度（Ａ）值比治疗前下降＜１５％为判断Ｈｐ阳转的疗效监测标准。第二阶段在另一批共６３例疗效监测患者中验证该标准，结果在停药６、１２个月呼气试验敏感性均为１００．０％，特异性分别为９５．５％及１００．０％；血清学敏感性均为１００．０％，特异性分别为５０．０％及８３．３％。结合两种方法的优缺点，提出在不同时期采用（１４）￣Ｃ－尿素呼气试验或血清学检测对治疗Ｈｐ感染进行疗效监测的联合方案。     

呼气试验:在消化病临床上应用和评价

呼气试验（Breathtests），由于其简便、易完成和无创性，已越来越多地应用于消化系功能的检测和疾病诊断（表1），其中，“G尿素呼气试验已成为幽门螺杆菌感染最重要的非创性诊断手段．表1呼气试验l肝如能检测＊．互NG氨基比林呼试验件O。noP加fi6b。th在。在）’‘O氨基比林在肝内由微粒体氧化为甲酸，再生成1‘O飞，从呼气中排出．口服已知剂量的“G氨基比林（通常l～Zofi），然后收集2h＄｛H呼气样本，检测其放射性．正常2h内呼气中排出的放射性为口服量的6．6％土1．3％，肝硬变和肝炎患者则明显降低，分别为2．6％士1．2％和2．6…     

不透X线标志物法和13C-辛酸呼气试验法检测胃固体排空的评价

目的 比较不透X线标志物法（ROMs）和^13C-辛酸呼气试验法（OBT）检测胃固体排空方法的相关性。方法 对32例胆汁反流性胃炎（BRG）组和27例对照组（HC）同时应用^13C-辛酸呼气试验及不透X线标志物法进行胃排空检测,将所测参数输入计算机,用专用软件分析。结果 不透X线标志物法与^13C-辛酸呼气试验法测定的胃排空结果具有很好的相关性（P〈0．001）,两种检测方法均显示BRG组的固体胃排空较HC组明显延迟（P〈0．05）。结论 不透X线标志物法是一种非侵入性检测胃固体排空的方法,操作简单,与^13C-辛酸呼气试验法比较,具有较好的敏感性、特异性及准确性。BRG患者有明显的胃排空延迟,这可能是其发生病理性胆汁反流的一个重要原因。     

幽门螺杆菌感染与冠心病发病的关系

目的 :探讨幽门螺杆菌 （Helicobacterpylori,HP）感染与冠心病的关系 ,进一步了解HP感染在冠心病发病中的作用。方法 :应用14 C尿素呼气试验对冠心病组 （10 1例 ）和非冠心病组 （5 3例 ）进行测定 ;应用ELISA法测定血清HP抗体 （HPIgG） ,确证慢性HP感染 ;分别应用ELISA法及放射免疫法测定冠心病组IL 6及内皮素 1（ET 1）。结果 :①冠心病组血清HPIgG阳性率显著高于非冠心病组 （4 6 %vs 2 8% ,P <0 .0 5 ） ;②冠心病组14 C尿素呼气试验阳性率显著高于非冠心病组 （5 4 %vs 30 % ,P <0 .0 1） ;③冠心病组慢性HP感染者血浆ET 1水平显著高于非HP感染者 （P<0 .0 5 ） ;④现症HP感染与糖尿病及空腹血糖升高有关 （P <0 .0 5 ）。结论 :HP慢性感染与冠心病有关。HP慢性感染者血浆内皮素水平显著升高。     

动态性肺过度充气与COPD患者劳力性呼吸困难的关系

目的探讨动态肺过度充气（DH）与COPD患者劳力性呼吸困难的关系。方法对我院42例COPD稳定期患者和20例健康体检者进行肺功能检测、症状限制递增功率心肺运动试验、高强度恒定功率运动试验,分别记录受试者静息状态和运动中的Borg呼吸困难评分、深吸气量（IC）、潮气量（VT）等指标。结果COPD组患者的呼吸变的浅快,呼气流速降低,呼气时问缩短,运动耐量显著低于对照组;COPD组患者在运动高峰时的Ic显著低于静息状态,对照组运动高峰时Ic与静息状态时无明显差别;COPD组患者运动终点与静息状态时Borg呼吸困难评分的差值（ABorg）与Ic的差值（AIC）呈负相关（r=-0．62,P〈0．05）,VT的差值（AVT）与AIC呈负相关（r=-0．80,P〈0．05）。结论动态性肺过度充气是慢性阻塞性肺疾病患者发生劳力性呼吸困难的原因之一,其产生与呼气呼气流速下降和呼气时间的缩短有关。     

呼气试验在消化系统疾病临床上的应用和评价

由于呼气试验简便、易完成和无创性，已越来越多地应用于消化系功能的检测和疾病诊断，其中１４Ｃ－尿素呼气试验已成为幽门螺杆菌（Ｈｐ）感染最重要的非创性诊断手段。１肝功能检测１１１４Ｃ－氨基比林呼气试验１４Ｃ氨基比林在肝内由微粒体氧化为甲酸，再生成１４Ｃ...     

13C-嘧噻西叮呼气试验对肝脏储备功能的诊断价值

目的探讨^13C-嘧噻西叮呼气试验用于肝脏储备功能检测的临床价值。方法将69例肝硬化患者分为Child A、B、C三组,另设7例为对照组。采集受试者不同时间点的呼气标本并检测^13C丰度,绘制丰度（delta over baseline,DOB）曲线、代谢速率（metabolisation velocity,MV）曲线和累积丰度（cumulated dose,CUM）曲线。结果随着Child—Pugh分级的升高,DOB、MV峰值出现时间延长,峰值降低（P〈0．05）,CUM曲线趋于低平;参数与部分常规肝功能检查呈相关性（P〈0．05）。结论^13C-嘧噻西叮呼气试验能够有效地反映肝细胞损伤情况和肝脏储备功能。     

Small Intestinal Bacterial Overgrowth in Gastroparesis

Objective

To determine symptoms of small intestinal bacterial overgrowth (SIBO) in gastroparesis patients.

Methods

Patients undergoing LBT (lactulose breath test) for evaluation of SIBO were included. LBT was considered positive on the basis of three conventional criteria: (1) hydrogen level increase >20 ppm above baseline by 90 min (H2@90min); (2) dual hydrogen peaks (>10 ppm increase over baseline before second peak >20 ppm (DPHBT); and (3) breath methane increase of >20 ppm above baseline by 90 min. Results of gastric emptying scintigraphy (GES) were recorded. Patients completed the Patient Assessment of Upper Gastrointestinal Disorders-Symptom Severity Index.

Results

Of 740 patients who underwent LBT from December 2009 to August 2011, 471 underwent GES, with 201 having delayed GES. Of patients with delayed GES who underwent LBT 87 % were female, 23 % diabetic, 49 % used gastric acid suppressants, 29 % used opiate analgesics, 35 % used pro-motility medications, and 27 % had a history of gastrointestinal surgery. Overall, 79 (39 %) patients with gastroparesis had evidence of SIBO by LBT: 30 (15 %) had positive H2@90min, 53 (26 %) positive DPHBT, and 6 (3 %) positive breath methane test. In gastroparesis patients with positive H2@90min, there was increased severity of bloating (3.80 ± 0.20 vs 3.29 ± 0.12; P = 0.02), early satiety (3.57 ± 0.27 vs 3.05 ± 0.13; P = 0.045), and postprandial fullness (4.20 ± 0.18 vs 3.52 ± 0.12; P < 0.01) compared with negative H2@90min patients. No significant difference in symptom severity was seen between positive and negative DPHBT gastroparesis patients.

Conclusion

In our cohort, 39 % of gastroparesis patients tested positive for SIBO by LBT. Positive H2@90min testing by LBT was associated with increased symptoms of bloating and excessive fullness during and after meals.     

Early hydrogen excretion peaks during breath tests. Small intestinal bacterial overgrowth or accelerated transit?

BackgroundSmall intestinal bacterial overgrowth (SIBO) has been reported with varying prevalence, depending upon the criteria used for diagnosis. Lactulose and glucose breath tests are the most used in clinical settings. Early rises of hydrogen excretion during a lactose breath test suggest SIBO, but the finding could result from accelerated mouth-to-caecum transit time.AimsDefining the prevalence of early hydrogen peaks during lactose breath tests and assessing the proportion of patients affected by SIBO.MethodsAn early (≤ 60′) hydrogen excretion peak was observed in 120/663 patients with positive lactose hydrogen breath test. Eighty-one of them underwent a 50 g-9sample-glucose hydrogen breath test to diagnose SIBO.ResultsThe glucose breath test proved positive in 11/81 (13.6%) patients. The positivity rate was 18.2% (2/11) in those with the first peak detected at 30′ and 12.8% (9/70) in those with the peak occurring at 60′.ConclusionsEarly hydrogen excretion peaks are rarely associated with SIBO. The low positive predictive value indicates that the finding does not help identifying patients at high risk for this condition. Indirectly, the present data support the opinion that the prevalence of SIBO diagnosed by standard lactulose breath tests is much lower than reported, and the reliability of the test is low.     

Bacterial concepts in irritable bowel syndrome

An overlap of symptoms in irritable bowel syndrome (IBS) exists across subtype groups. Symptoms include intestinal gas, diarrhea, dyspepsia, bloating, abdominal pain, and constipation. The unifying symptom may be excessive intestinal gas as a by-product of intestinal microbial fermentation. Abnormal fermentation of food takes place when gut microbes expand proximally into the small intestine instead of being confined predominantly to the colon. Such proximal expansion of indigenous gut microbes or small intestinal bacterial overgrowth (SIBO) may lead to activation of host mucosal immunity and an increase in intestinal permeability to result in flu-like extra-intestinal symptoms that accompany the classic IBS symptoms of altered bowels. The presence of methane on lactulose breath testing is associated with constipation-predominant IBS. Antibiotic therapy may be appropriate to treat underlying SIBO in IBS patients. Seventy-five percent improvement of IBS symptoms was reported in a double-blind, placebo-controlled study once antibiotics succeeded in treating bacterial overgrowth. Once a good clinical response and normalization of the lactulose breath test are achieved, a prokinetic agent may be used to stimulate phase III of interdigestive motility to delay relapse of bacterial overgrowth.     

Detection of bacterial overgrowth in IBS using the lactulose H2 breath test: comparison with 14C-D-xylose and healthy controls

OBJECTIVES Recent reports suggest bacterial overgrowth is commonly associated with irritable bowel syndrome (IBS) when diagnosed using the lactulose hydrogen breath test (LHBT). We employed this test to examine whether similar findings exist in a geographically distinct population of Rome II positive IBS patients and compared it to the 14C-D-xylose breath test, a test with acknowledged greater specificity for bacterial overgrowth. METHODS: In the first series, Rome II IBS patients underwent a 10 g lactulose breath test and a standardized 1 g 14C-D-xylose breath test and answered IBS symptom questionnaires. A positive test required an elevated breath hydrogen concentration within 90 min, two distinct peaks, and an increase >20 ppm. In a second series, control patients lacking gastrointestinal symptoms underwent a lactulose breath test. A positive test required an elevation of breath hydrogen >20 ppm within 90 or 180 min. These criteria were also applied to lactulose breath tests from IBS cases in series one. RESULTS: The IBS patients were predominantly female (64%) and most reported severe symptoms (80%). The majority had diarrhea predominant symptoms (63%) and only 3% were constipation predominant. In the first series, only 10% of patients had a positive lactulose breath test and 13% had a positive 14C-D-xylose test. In the second series, the number of abnormal LHBTs was much higher but no differences were found between IBS patients and controls. CONCLUSION: The lactulose breath test did not reliably detect a common association between bacterial overgrowth and IBS in our patient population.     

Small Intestinal Bacterial Overgrowth and Orocecal Transit Time in Patients of Inflammatory Bowel Disease

Background

Inflammatory bowel disease (IBD) consists of Ulcerative colitis (UC) and Crohn’s disease (CD). These two conditions share many common features—diarrhea, bloody stools, weight loss, abdominal pain, fever and fatigue. Small intestinal bacterial overgrowth (SIBO) is frequent in patients with CD but it has not been studied in UC Indian patients.

Aim

The study was planned to measure orocecal transit time (OCTT) and SIBO in UC and CD patients.

Methods

One hundred thirty-seven patients of IBD (95 UC and 42 CD) and 115 healthy controls were enrolled. OCTT and SIBO were measured by lactulose and glucose hydrogen breath test respectively. Concentration of hydrogen and methane were measured by SC microlyser from Quintron, USA.

Results

Mean ± standard deviation (SD) of OCTT in patients of IBD was significantly higher as compared to controls. Furthermore, OCTT was significantly higher in CD patients as compared to UC patients. It was also observed that occurrence of SIBO was significantly higher in IBD patients as compared to controls. The occurrence of SIBO in CD (45.2 %) was significantly higher as compared to patients in UC (17.8 %) group. Percentage of methane positive IBD patients (2.9 %) was significantly lower as compared to methane positive controls (24.4 %).

Conclusion

OCTT was significantly delayed in IBD patients as compared to controls and in CD patients as compared to UC patients. OCTT was significantly higher in SIBO positive IBD patients as compared to SIBO negative patients. Thus, we can suggest that delayed OCTT would have been the cause of increased SIBO in these patients.     

Lactose malabsorption in the elderly: role of small intestinal bacterial overgrowth

OBJECTIVE: The prevalence of lactose malabsorption (LM) is increased in the elderly, although the mechanisms responsible are still a matter of speculation. The objective of this study was to investigate the possible roles of reduced functional small intestinal absorptive area, lactase deficiency and small intestinal bacterial overgrowth (SIBO). MATERIAL AND METHODS: Twenty Caucasian (Anglo-Celtic), asymptomatic, well-nourished, elderly volunteers (median age 79 years, range 70-94 years) with no clinically apparent predisposition to SIBO underwent a 50 g lactose breath hydrogen test (LBHT) and mannitol absorption test, the latter as an index of functional small intestinal absorptive area. Those with LM additionally underwent bacteriological assessment of small intestinal secretions and mucosal biopsy, to assess the contribution of SIBO and lactase deficiency, respectively, to the pathogenesis of LM in individual cases. The prevalence of SIBO was also determined in elderly subjects without LM. Twenty asymptomatic younger subjects (median age 29 years, age range 18-35 years) served as controls. All subjects were "hydrogen producers" in response to lactulose. RESULTS: LM was evident in 10/20 (50%) elderly subjects and 1/20 (5%) younger subjects (p=0.003). Mannitol absorption did not differ significantly in elderly and younger subjects or in elderly subjects with and without LM. SIBO was documented in 9/10 (90%) elderly subjects with LM; eradication was associated with resolution of LM. Lactase deficiency was evident in only one elderly subject with LM. SIBO was evident in 2/10 (20%) elderly subjects without LM (p=0.005 compared to those with LM). Lactulose breath hydrogen test identified only 2/11 (18%) elderly subjects with SIBO. CONCLUSIONS: Increased prevalence of LM in the elderly is mostly due to clinically non-apparent SIBO, rather than mucosal factors. The lactulose breath hydrogen test cannot be relied upon to identify elderly subjects with SIBO, even in those without an anatomical predisposition.     

Breath hydrogen response to lactulose in healthy subjects: relationship to methane producing status.

In order to assess the relationship between methane (CH4) producing status and the breath excretion of hydrogen (H2) in healthy subjects, breath CH4 and H2 were simultaneously measured for 14 hours after oral ingestion of 10 g lactulose in 65 young volunteers. Forty were breath CH4 producers and 25 were not. Statistically significant differences were observed between both groups, with lower values for CH4 producers recorded for the following parameters: fasting basal value of breath H2 (8.1 (4.9) v 5.2 (3.7) ppm, p less than 0.05), mouth-to-caecum transit time (68 (24) v 111 (52) min, p less than 0.005), and breath H2 production measured as area under the curve 13.1 (6.9) v 8.8 (3.8) 10(3) ppm/min, p less than 0.02). There was no significant correlation between individual production of breath H2 and CH4. These results indicate that the response to lactulose depends on breath CH4 producing status. In clinical practice, defining normal values of mouth-to-caecum transit time without knowledge of breath CH4 producing status may lead to misinterpretation of the H2 breath test.     

Methane production and small intestinal bacterial overgrowth in children living in a slum

AIM:To analyze small intestinal bacterial overgrowth in school-aged children and the relationship between hydrogen and methane production in breath tests.METHODS:This transversal study included 85 children residing in a slum and 43 children from a private school,all aged between 6 and 10 years,in Osasco,Brazil.For characterization of the groups,data regarding the socioeconomic status and basic housing sanitary conditions were collected.Anthropometric data was obtained in children from both groups.All children completed the hydrogen(H 2) and methane(CH 4) breath test in order to assess small intestinal bacterial overgrowth(SIBO).SIBO was diagnosed when there was an increase in H 2 ≥ 20 ppm or CH 4 ≥ 10 ppm with regard to the fasting value until 60 min after lactulose ingestion.RESULTS:Children from the slum group had worse living conditions and lower nutritional indices than children from the private school.SIBO was found in 30.9%(26/84) of the children from the slum group and in 2.4%(1/41) from the private school group(P = 0.0007).Greater hydrogen production in the small intestine was observed in children from the slum group when compared to children from the private school(P = 0.007).A higher concentration of hydrogen in the small intestine(P 0.001) and in the colon(P 0.001) was observed among the children from the slum group with SIBO when compared to children from the slum group without SIBO.Methane production was observed in 63.1%(53/84) of the children from the slum group and in 19.5%(8/41) of the children from the private school group(P 0.0001).Methane production was observed in 38/58(65.5%) of the children without SIBO and in 15/26(57.7%) of the children with SIBO from the slum.Colonic production of hydrogen was lower in methaneproducing children(P = 0.017).CONCLUSION:Children who live in inadequate environmental conditions are at risk of bacterial overgrowth and methane production.Hydrogen is a substrate for methane production in the colon.     

Lactose malabsorption in the elderly: Role of small intestinal bacterial overgrowth

Objective. The prevalence of lactose malabsorption (LM) is increased in the elderly, although the mechanisms responsible are still a matter of speculation. The objective of this study was to investigate the possible roles of reduced functional small intestinal absorptive area, lactase deficiency and small intestinal bacterial overgrowth (SIBO). Material and methods. Twenty Caucasian (Anglo-Celtic), asymptomatic, well-nourished, elderly volunteers (median age 79 years, range 70–94 years) with no clinically apparent predisposition to SIBO underwent a 50 g lactose breath hydrogen test (LBHT) and mannitol absorption test, the latter as an index of functional small intestinal absorptive area. Those with LM additionally underwent bacteriological assessment of small intestinal secretions and mucosal biopsy, to assess the contribution of SIBO and lactase deficiency, respectively, to the pathogenesis of LM in individual cases. The prevalence of SIBO was also determined in elderly subjects without LM. Twenty asymptomatic younger subjects (median age 29 years, age range 18–35 years) served as controls. All subjects were “hydrogen producers” in response to lactulose. Results. LM was evident in 10/20 (50%) elderly subjects and 1/20 (5%) younger subjects (p=0.003). Mannitol absorption did not differ significantly in elderly and younger subjects or in elderly subjects with and without LM. SIBO was documented in 9/10 (90%) elderly subjects with LM; eradication was associated with resolution of LM. Lactase deficiency was evident in only one elderly subject with LM. SIBO was evident in 2/10 (20%) elderly subjects without LM (p=0.005 compared to those with LM). Lactulose breath hydrogen test identified only 2/11 (18%) elderly subjects with SIBO. Conclusions. Increased prevalence of LM in the elderly is mostly due to clinically non-apparent SIBO, rather than mucosal factors. The lactulose breath hydrogen test cannot be relied upon to identify elderly subjects with SIBO, even in those without an anatomical predisposition.     

Methane production during lactulose breath test is associated with gastrointestinal disease presentation

It has recently been determined that there is an increased prevalence of bacterial overgrowth in IBS. Since there are two gases (hydrogen and methane) measured on lactulose breath testing, we evaluated whether the different gas patterns on lactulose breath testing coincide with diarrhea and constipation symptoms in IBS and IBD. Consecutive patients referred to the gastrointestinal motility program at Cedars-Sinai Medical Center for lactulose breath testing were given a questionnaire to evaluate their gastrointestinal symptoms. Symptoms were graded on a scale of 0–5. Upon completion of the breath test, the results were divided into normal, hydrogen only, hydrogen and methane, and methane only positive breath tests. A comparison of all subjects and IBS subjects was undertaken to evaluate diarrhea and constipation with regards to the presence or absence of methane. This was further contrasted to Crohn's and ulcerative colitis (UC) patients in the database. After exclusion criteria, 551 subjects from the database were available for comparison. Of the 551 subjects (P < 0.05, one-way ANOVA) and in a subgroup of 296 IBS subjects (P < 0.05, one-way ANOVA), there was a significant association between the severity of reported constipation and the presence of methane. The opposite was true for diarrhea (P < 0.001). If a breath test was methane positive, this was 100% associated with constipation predominant IBS. Furthermore, IBS had a greater prevalence of methane production than Crohn's or UC. In fact, methane was almost nonexistent in the predominantly diarrheal conditions of Crohn's and UC. In conclusion, a methane positive breath test is associated with constipation as a symptom.