Evaluation of the rice breath hydrogen test for small intestinal bacterial overgrowth

OBJECTIVES: The aims of this study were 1) to document the sensitivity, specificity, and predictive values of the rice breath hydrogen test for small intestinal bacterial overgrowth; 2) to determine the possible influence of concurrent gastric bacterial overgrowth and gastroduodenal pH on the efficacy of this test; and 3) to investigate whether reliability is limited by an inability of small intestinal luminal flora to ferment rice or its product of hydrolysis, maltose. METHODS: Twenty adult subjects were investigated with microbiological culture of proximal small intestinal aspirate and a 3-g/kg rice breath hydrogen test. Gastroduodenal pH, the presence or absence of gastric bacterial overgrowth, and the in vitro capability of small intestinal luminal flora to ferment rice and maltose, its product of hydrolysis, were determined. RESULTS: Sensitivity of the rice breath hydrogen test for small intestinal bacterial overgrowth was 33% and remained low even when subjects with small intestinal overgrowth with oropharyngeal-type (38%) and colonic-type flora (20%) and those with concurrent small intestinal and gastric bacterial overgrowth (40%) were considered separately. Sensitivity remained suboptimal despite favorable gastroduodenal luminal pH and documented ability of bacterial isolates to ferment rice and maltose in vitro. Specificity of the rice breath hydrogen test for small intestinal bacterial overgrowth was 91%. Positive predictive value, negative predictive value, and predictive accuracy were 75%, 63%, and 65%, respectively. CONCLUSIONS: Clinical value of the rice breath hydrogen test for detecting small intestinal bacterial overgrowth is limited. The rice breath hydrogen test is not a suitable alternative to small intestinal intubation and culture of secretions for the detection of small intestinal bacterial overgrowth.     

硫化氢呼气试验在小肠细菌过度生长诊断中的应用价值初探

目的:探究硫化氢呼气试验（hydrogen sulfide breath test,SBT）在小肠细菌过度生长（small intestinal bacterial overgrowth, SIBO）诊断中的应用价值。方法:纳入2019年4—12月某高校学生,进行消化道症状和1周膳食问卷调查,以及乳果糖氢-甲烷呼气试验...     

肝硬化患者病情与小肠细菌过度生长变化关系探讨

目的 探讨小肠细菌过度生长（SIBO）与肝硬化病情严重程度的关系及小肠细菌生长与降钙素原、胆红素、血浆白蛋白、球蛋白的相关性。方法 纳入本科收治的47例肝硬化患者和15名健康志愿者。受试者接受乳果糖氢呼气试验（LHBT）,检测小肠细菌过度生长情况,使用全自动生化分析仪测定生化指标。采用自评表形式对肝硬化组患者症状进行评估。结果 在15名健康志愿者中检出1例（6.6%）伴小肠细菌过度生长,而在47例肝硬化患者中检出22例（46.8%）患者伴小肠细菌过度生长,显著高于正常人（P＜0.01）;肝硬化患者LHBT集值为（157.81±98.32）ppm,显著高于健康人[(38.87±16.05）ppm,P＜0.01],血清胆红素为（93.31±55.15）μmol/L,显著高于健康人[（14.78±8.12）μmol/L,P＜0.01],白蛋白为（31.74±10.37）g/L,显著低于健康人[(43.90±7.63) g/L, P＜0.01],球蛋白为（39.09±5.07）g/L,高于健康人[(35.94±2.31) g/L,P＞0.05],降钙素原为（0.10±0.07）ng/ml,显著高于健康人[(0.03±0.01) ng/ml,P＜0.01];降钙素原、胆红素、血浆白蛋白、球蛋白与LHBT集值具有相关性（r=0.895、P＜0.005,r=0.907、P＜0.005,r=-0.810、P＜0.005,r=0.755,P＜0.005）。结论 肝硬化患者SIBO发生率随肝功能损害程度的加重而增加,肝硬化SIBO患者腹胀及食欲不振更明显。降钙素原、胆红素和球蛋白分别与SIBO呈正相关,血浆白蛋白与SIBO呈负相关。     

Comparison of the 1-gram (14)C-D-xylose breath test and the 50-gram hydrogen glucose breath test for diagnosis of small intestinal bacterial overgrowth

BACKGROUND/AIMS: Culture of small bowel aspirate is the most direct method and the gold standard for diagnosing small intestinal bacterial overgrowth. However, cultures are cumbersome and fluoroscopy is required for obtaining aspirate. Therefore, different breath tests such as the xylose breath test and the hydrogen breath test have been developed. There is no general agreement as to which test is to be preferred. In the only previous direct comparison between these two tests an advantage for the 1-gram-(14)C-D-xylose breath test was found. The aim of the study was to compare the 50-gram glucose hydrogen breath test and the 1-gram (14)C-D-xylose breath test in relation to results of cultures of small bowel aspirate. METHODS: Forty-six consecutive patients, mean age 57 (range 27-87) years, 12 men and 34 women, were included because of suspicion of small intestinal bacterial overgrowth. After small bowel aspiration, all patients received a solution of 1 g xylose, labelled with 50 microg (14)C-D-xylose, and 50 g glucose dissolved in 250 ml water. The concentration of breath hydrogen was analyzed every 15 min for 2 h and (14)CO(2) was analyzed every 30 min for 4 h. A positive hydrogen breath test was defined as a rise in hydrogen concentration of 15 ppm. A positive xylose test was defined as an accumulated dose 4.5% after 4 h. Two definitions for a positive culture were used, either growth of 10(5 )colonic-type bacteria/ml or growth of 10(5) bacteria/ml of any type. RESULTS: Twenty-four patients had growth of 10(5) bacteria, of whom 10 had growth of 10(5) colonic-type bacteria in small bowel aspirate. Twenty-two patients had no significant growth. The hydrogen breath test and the xylose breath test had a sensitivity for growth of 10(5) bacteria of 58 and 42%, respectively. For growth of 10(5 )colonic-type bacteria the sensitivity was 90% for the hydrogen breath test and 70% for the xylose breath test. The specificity was similar for the two tests. CONCLUSION: Although no significant difference between the two tests was found, there was a tendency in favor of the 50-gram glucose hydrogen breath test. The simplicity in combination with high sensitivity makes the hydrogen breath test suitable as a screening method to select patients for further investigation.     

Value of the 14C-D-xylose breath test in patients with intestinal bacterial overgrowth

18 control subjects and 18 patients, with a variety of gastrointestinal conditions were investigated using a 10-muCi 14C-D-xylose breath test. The latter also underwent quantitative bacterial studies of fluid obtained by intestinal intubation. In 14 patients a smaller dose of 3 muCi 14C-D-xylose was compared to the standard dose and there was a good correlation between the two doses. The peak value of the 14C-D-xylose test provided the best discrimination between patients with and without bacterial overgrowth. The 14C-glycocholic acid test performed in 15 patients, although as sensitive, was less discriminating. The 14C-D-xylose breath test is reliable and more specific in confirming the diagnosis of small intestinal bacterial overgrowth without having to resort to direct bacterial studies.     

肝硬化患者小肠细菌过度生长在肠道气体产生中的作用

肝硬化是我国常见疾病和主要死亡原因之一,肝硬化患者由于门静脉高压致胃肠道瘀血、胆汁酸和胃酸的相对缺乏、肠道运动障碍等因素,可导致肠腔需氧菌增多,结肠的细菌移行至空肠和十二指肠,引起小肠细菌过度生长(small intestinal bacterial overgrowth,SIBO),继而增加内源性感染的机会[1].在临床中发现,肝硬化患者常伴有肠道气体增多,并导致肠胀气、腹胀、腹痛等症状,影响患者生活质量及增加临床治疗难度,目前肝硬化小肠细菌过度生长与肝性脑病、内毒素血症的关系研究较多[2-3],但有关肝硬化小肠细菌过度生长与肠道气体形成的研究较少.本研究通过观察肝硬化伴小肠细菌过度生长患者经过微生态制剂治疗后肠道气体的变化,旨在探讨小肠细菌过度生长在肝硬化患者肠道气体产生中的作用,希望为肝硬化患者肠道气体的治疗提供新的方向.     

Diagnosis and treatment of small intestinal bacterial overgrowth

A huge number of bacteria are hosted in the gastrointestinal tract, following a gradient increasing towards the colon. Gastric acid secretion and intestinal clearance provide the qualitative and quantitative partitioning of intestinal bacteria; small intestinal bacteria overgrowth (SIBO) occurs when these barrier mechanisms fail. Diagnosis of SIBO is challenging due to the low specificity of symptoms, the frequent association with other diseases of the gastrointestinal tract and the absence of optimal objective diagnostic tests. The therapeutic approach to SIBO is oriented towards resolving predisposing conditions, and is supported by antibiotic treatment to restore the normal small intestinal microflora and by modifications of dietary habits for symptomatic relief. In the near future, metagenomics and metabolomics will help to overcome the uncertainties of SIBO diagnosis and the pitfalls of therapeutic management, allowing the design of a personalized strategy based on the direct insight into the small intestinal microbial community.     

Use of the lactose-[13C]ureide breath test for diagnosis of small bowel bacterial overgrowth: comparison to the glucose hydrogen breath test

Purpose  

The glucose hydrogen breath test (GHBT) is commonly used as a noninvasive test to diagnose small bowel bacterial overgrowth (SBBO) but its validity has been questioned. Our aim was to evaluate the lactose-[¹³C]ureide breath test (LUBT) to diagnose SBBO and to compare it with the GHBT, using cultures of intestinal aspirates as a gold standard.     

乙型肝炎后肝硬化患者小肠细菌过度生长情况的研究

[目的]探讨乙型肝炎后肝硬化患者的小肠细菌过度生长(SIBO)情况,以及SIBO与其肝功能状况、HBV-DNA之间的关系。[方法]将42例乙型肝炎后肝硬化患者按肝功能Child-Pugh分级分为A级、B级、C级三组,并入选同期门诊体检的健康者20例作为健康对照组。通过葡萄糖氢呼气试验(GHBT)检测并比较分析各组SIBO情况,同时检测并比较分析肝硬化患者各组的HBV-DNA水平及其SIBO阳性率。[结果]肝硬化各组患者与健康对照组的SIBO阳性率及试餐后呼气氢浓度比较均差异有统计学意义(P0.05)。肝硬化患者的SIBO阳性率及试餐后呼气氢浓度均随着Child-Pugh分级低下而呈渐进性增高,各组间差异有统计学意义(P0.05)。肝硬化患者各组间的SIBO阳性率及试餐后呼气氢浓度比较,HBV-DNA10~3时均明显高于HBV-DNA≤10~3时,且差异有统计学意义(P0.05)。[结论]乙型肝炎后肝硬化患者常存在SIBO,且随着肝功能恶化、HBV-DNA拷贝数增加,其SIBO加重,由此推测防治SIBO,可能对乙型肝炎后肝硬化患者的肝功能改善、乙肝病毒清除有益。     

Diagnosis of small intestinal bacterial overgrowth: the challenges persist!

Small intestinal bacterial overgrowth was originally defined in the context of an overt malabsorption syndrome and diagnostic tests were developed and validated accordingly. More recently, the concept of intestinal contamination with excessive numbers of bacteria, especially those of colonic type, has been extended beyond the bounds of frank maldigestion and malabsorption to explain symptomatology in disorders as diverse as irritable bowel syndrome, celiac sprue and nonalcoholic fatty liver disease. Owing to a lack of consensus with regard to the optimal diagnostic criteria (the ‘gold standard’) for the diagnosis of bacterial overgrowth, the status of these new concepts is unclear. This review sets out to critically appraise the various diagnostic approaches that have been taken and are currently employed to diagnose small intestinal bacterial overgrowth.     

Small intestinal motility disturbances and bacterial overgrowth in patients with liver cirrhosis and portal hypertension

OBJECTIVE: Altered small bowel motility and a high prevalence of small intestinal bacterial overgrowth (SIBO) has been observed in patients with liver cirrhosis. Our aim was to explore the relationship between motility abnormalities, portal hypertension, and SIBO. METHODS: Twenty-four patients with liver cirrhosis were included. Twelve had portal hypertension (PH) and 12 had liver cirrhosis (LC) alone. Child-Pugh score was the same in the groups. Antroduodenojejunal pressure recordings were performed, and noninvasive variceal pressure measurements were undertaken. Thirty-two healthy volunteers served as a reference group. Bacterial cultures were obtained from jejunal aspirates. RESULTS: The PH group had a higher proportion of individual pressure waves that were retrograde in the proximal duodenum during phase II (52% vs 13% vs 8% of propagated contractions; p < 0.001) as well as postprandially (49% vs 18% vs 13%; p < 0.01) compared with LC and controls, respectively. Long clusters were more common in PH than in controls (9.1 +/- 2.1 vs 4.9 +/- 0.8; p < 0.05), and a higher motility index in phase III in the proximal and distal duodenum was seen in the PH as compared with the other groups. The mean variceal pressure was 21 +/- 1 mm Hg. Motor abnormalities were not correlated to the level of variceal pressure. Thirty-three percent of the patients in the PH group but none in the LC group had SIBO. CONCLUSIONS: Abnormal small bowel motility and SIBO is common in patients with liver cirrhosis with concomitant portal hypertension. Portal hypertension per se might be significantly related to small bowel abnormalities observed in patients with liver cirrhosis.     

Predisposing factors for positive D-Xylose breath test for evaluation of small intestinal bacterial overgrowth: A retrospective study of 932 patients

AIM: To investigate, in the largest cohort to date, patient characteristics and associated risk factors for developing small intestinal bacterial overgrowth (SIBO) using the D-Xylose breath test (XBT).METHODS: We performed a retrospective cross-sectional study to analyze patient characteristics who underwent the XBT for evaluation of SIBO. Diagnostic testing with the XBT was performed based on a clinical suspicion for SIBO in patients with symptoms of bloating, abdominal pain, abdominal distension, weight loss, diarrhea, and/or constipation. Consecutive electronic medical records of 932 patients who completed the XBT at the University of Florida between 2005 and 2009 were reviewed. A two-way Analysis of Variance (ANOVA) was used to test for several associations including age, gender, and body mass index (BMI) with a +XBT. A two-way ANOVA was also performed to control for the differences and interaction with age and between genders. A similar analysis was repeated for BMI. Associations between medical conditions and prior surgical histories were conducted using the Mantel-Haenszel method for 2 by 2 contingency tables, stratified for gender. Reported odds ratio estimates reflect the odds of the prevalence of a condition within the +XBT group to that of the -XBT group. P values of less than 0.05 (two-sided) were considered statistically significant.RESULTS: In the 932 consecutive eligible subjects studied, 513 had a positive XBT. A positive association was found between female gender and a positive XBT (P = 0.0025), and females with a positive test were, on average, greater than 5 years older than those with a negative test (P = 0.024). The mean BMI of positive XBT subjects was normal (24.5) and significantly lower than the subjects with a negative XBT (29.5) (P = 0.0050). A positive XBT was associated with gastroesophageal reflux disease (GERD) (OR = 1.35; 95%CI: 1.02-1.80, P = 0.04), peptic ulcer disease (PUD) (OR = 2.61; 95%CI: 1.48-4.59, P < 0.01), gastroparesis (GP) (OR = 2.04; 95%CI: 1.21-3.41, P < 0.01) and steroid use (OR = 1.35; 95%CI: 1.02-1.80, P = 0.01). Irritable bowel syndrome, independent proton-pump inhibitor (PPI) usage, or previous abdominal surgery was not significantly associated with a positive XBT. No single subdivision by gender or PPI use was associated with a significant difference in the odds ratios between any of the subsets.CONCLUSION: Female gender, lower BMI, steroid use, PUD, GERD (independent of PPI use), and GP were more prevalent in patients with SIBO, determined by a positive XBT. Increasing age was associated with SIBO in females, but not in males.     

Bone mineral density in patients with small intestinal bacterial overgrowth

BACKGROUND/AIMS: Malabsorption has long been recognized as a cause of osteopenia, and mild forms of osteopenia are present in many gastrointestinal disorders. The aim of this study was to determine if osteopenia is common in patients with small intestinal bacterial overgrowth. METHODOLOGY: Bone mineral density was measured in fourteen patients with small intestinal bacterial overgrowth. Patients with obvious structural predisposing conditions such as previous gastric operations, small bowel strictures and small bowel diverticula, were excluded. Measurements were made in the distal right radius and ulna, in the hip and in the spine. The results were compared to those of a reference population. Radiographs of the spine were assessed for evidence of vertebral fractures. Blood samples were analyzed for serum concentrations of 25-hydroxyvitamin-D3 and 1,25-dihydroxyvitamin-D3, alkaline phosphatase activity, ionized calcium, intact parathyroid hormone and osteocalcin. All patients completed a questionnaire concerning, inter alia, previous fractures, past and current diseases, tobacco smoking and medication. RESULTS: Patients with small intestinal bacterial overgrowth had significantly low bone density in the femoral neck (p < 0.01) and in the lumbar spine (p < 0.05), compared to a reference population. Six of 14 (43%) patients had had fractures. CONCLUSIONS: Patients with small intestinal bacterial overgrowth have low bone mineral density. In patients with osteopenia of unknown origin, small intestinal bacterial overgrowth should be considered.