Showing papers on "Breath test published in 2018"

Assessment of a Noninvasive Exhaled Breath Test for the Diagnosis of Oesophagogastric Cancer.

Abstract: Importance Early esophagogastric cancer (OGC) stage presents with nonspecific symptoms. Objective The aim of this study was to determine the accuracy of a breath test for the diagnosis of OGC in a multicenter validation study. Design, Setting, and Participants Patient recruitment for this diagnostic validation study was conducted at 3 London hospital sites, with breath samples returned to a central laboratory for selected ion flow tube mass spectrometry (SIFT-MS) analysis. Based on a 1:1 cancer:control ratio, and maintaining a sensitivity and specificity of 80%, the sample size required was 325 patients. All patients with cancer were on a curative treatment pathway, and patients were recruited consecutively. Among the 335 patients included; 172 were in the control group and 163 had OGC. Interventions Breath samples were collected using secure 500-mL steel breath bags and analyzed by SIFT-MS. Quality assurance measures included sampling room air, training all researchers in breath sampling, regular instrument calibration, and unambiguous volatile organic compounds (VOCs) identification by gas chromatography mass spectrometry. Main Outcomes and Measures The risk of cancer was identified based on a previously generated 5-VOCs model and compared with histopathology-proven diagnosis. Results Patients in the OGC group were older (median [IQR] age 68 [60-75] vs 55 [41-69] years) and had a greater proportion of men (134 [82.2%]) vs women (81 [47.4%]) compared with the control group. Of the 163 patients with OGC, 123 (69%) had tumor stage T3/4, and 106 (65%) had nodal metastasis on clinical staging. The predictive probabilities generated by this 5-VOCs diagnostic model were used to generate a receiver operator characteristic curve, with good diagnostic accuracy, area under the curve of 0.85. This translated to a sensitivity of 80% and specificity of 81% for the diagnosis of OGC. Conclusions and Relevance This study shows the potential of breath analysis in noninvasive diagnosis of OGC in the clinical setting. The next step is to establish the diagnostic accuracy of the test among the intended population in primary care where the test will be applied.

The potential role of exhaled breath analysis in the diagnostic process of pneumonia-a systematic review

Abstract: Diagnostic strategies currently used for pneumonia are time-consuming, lack accuracy and suffer from large inter-observer variability. Exhaled breath contains thousands of volatile organic compounds (VOCs), which include products of host and pathogen metabolism. In this systematic review we investigated the use of so-called 'breathomics' for diagnosing pneumonia. A Medline search yielded 18 manuscripts reporting on animal and human studies using organic and inorganic molecules in exhaled breath, that all could be used to answer whether analysis of VOC profiles could potentially improve the diagnostic process of pneumonia. Papers were categorised based on their specific aims; the exclusion of pneumonia; the detection of specific respiratory pathogens; and whether targeted or untargeted VOC analysis was used. Ten studies reported on the association between VOCs and presence of pneumonia. Eight studies demonstrated a difference in exhaled VOCs between pneumonia and controls; in the individual studies this discrimination was based on unique sets of VOCs. Eight studies reported on the accuracy of a breath test for a specific respiratory pathogen: five of these concerned pre-clinical studies in animals. All studies were valued as having a high risk of bias, except for one study that used an external validation cohort. The findings in the identified studies are promising. However, as yet no breath test has been shown to have sufficient diagnostic accuracy for pneumonia. We are in need of studies that further translate the knowledge from discovery studies to clinical practice.

The safety and sensitivity of a telemetric capsule to monitor gastrointestinal hydrogen production in vivo in healthy subjects: a pilot trial comparison to concurrent breath analysis.

Abstract: Background Intestinal gases are currently used for the diagnosis of disorders including small intestinal bacterial overgrowth and carbohydrate malabsorption. Aim To compare the performance of measuring hydrogen production within the gut directly with the telemetric gas-sensing capsule with that of indirect measurement through breath testing. Methods Using standard breath testing protocols, the capsules and breath tests were simultaneously evaluated in a single-blinded trial in 12 healthy subjects. Eight received a single dose of 1.25-40 g inulin and four 20 or 40 g glucose. Safety and reliability of the capsules were also assessed. Results There were no reported adverse events. All capsules were retrieved and operated without failure. Capsule measurements were in agreement with breath test measurements in magnitude but not in timing; minimal hydrogen production was observed after glucose ingestion and capsule measurements correlated with breath hydrogen after ingestion of 40 g inulin. A dose-dependent increase in concentration of hydrogen was observed from the capsule following ingestion of inulin as low as 1.25 g compared with >10 g for breath measurements. Specifically, the capsule measured >3000 times higher concentrations of hydrogen compared to breath tests, resulting in a signal-to-noise ratio of 23.4 for the capsule compared to 4.2 for the breath test. Conclusions The capsule showed high sensitivity and signal-to-noise ratio in measuring luminal hydrogen concentrations, provided information on the site of intestinal gas production, and demonstrated safety and reliability. The capsule has potential for improving diagnostic precision for disorders such as small intestinal bacterial overgrowth.

Human erythrocyte lifespan measured by Levitt's CO breath test with newly developed automatic instrument.

Abstract: Existing standard techniques for erythrocyte (RBC) lifespan measurement, such as quantitation of labeling with isotopes or biotin, are cumbersome and time-consuming. Given that endogenous CO originates mainly from degraded RBCs, a team lead by Levitt developed a CO breath test to enable more efficient RBC lifespan estimation. The purpose of this study was to evaluate the reliability of Levitt's CO breath test method with our newly developed automatic instrument. RBC lifespan measurements conducted by Levitt's CO breath test method were conducted in 109 healthy subjects and 91 patients with chronic hemolytic anemia. In healthy subjects, the RBC lifespan was 126 ± 26 days, similar to values obtained with classical standard labeling methods. RBC lifespan did not differ significantly between males and females or between juveniles and adults, and did not correlate with age. To our knowledge, this datum represents an RBC lifespan average for the largest sample to date. In subjects with hemolytic anemia, RBC lifespan was 29 ± 14 days, which is significantly shorter than that of the healthy subjects (p = 0.001). Using 75 days as a cut-off, diagnostic accuracy for hemolytic anemia in the present study sample was 100%. In conclusion, the present results indicate that Levitt's CO breath test is an ideal method for human RBC lifespan measurement, and the newly developed automatic instrument is reliable and convenient for clinical practice.

New fecal test for non-invasive Helicobacter pylori detection: A diagnostic accuracy study.

Abstract: Aim To assess the diagnostic accuracy of a new fecal test for detecting Helicobacter pylori (H. pylori), using13C-urea breath test as the reference standard, and explore bacterial antibiotic resistance. Methods We conducted a prospective two-center diagnostic test accuracy study. We enrolled consecutive people≥ 18 years without previous diagnosis of H. pylori infection, referred for dyspepsia between February and October 2017. At enrollment, all participants underwent 13C-urea breath test. Participants aged over 50 years were scheduled to undergo upper endoscopy with histology. Participants collected stool samples 1-3 d after enrollment for a new fecal investigation (THD fecal test). The detection of bacterial 23S rRNA subunit gene indicated H. pylori infection. We also used the index diagnostic test to examine mutations conferring resistance to clarithromycin and levofloxacin. Independent investigators analyzed index test and reference test standard results blinded to the other test findings. We estimated sensitivity, specificity, positive (PPV) and negative (NPV) predictive value, diagnostic accuracy, positive and negative likelihood ratio (LR), together with 95% confidence intervals (CI). Results We enrolled 294 consecutive participants (age: Median 37.0 years, IQR: 29.0-46.0 years; men: 39.8%). Ninety-five (32.3%) participants had a positive13C-urea breath test. Twenty-three (7.8%) participants underwent upper endoscopy with histology, with a full concordance between 13C-urea breath test and histology in detecting H. pylori infection. Four (1.4%) out of the 294 participants withdrew from the study after the enrollment visit and did not undergo THD fecal testing. In the 290 participants who completed the study, the THD fecal test sensitivity was 90.2% (CI: 84.2%-96.3%), specificity 98.5% (CI:96.8%-100%), PPV 96.5% (CI: 92.6%-100%), NPV 95.6% (CI: 92.8%-98.4%), accuracy 95.9% (CI: 93.6%-98.2%), positive LR 59.5(CI: 19.3-183.4), negative LR 0.10 (CI: 0.05-0.18). Out of 83 infected participants identified with the THD fecal test, 34 (41.0%) had bacterial genotypic changes consistent with antibiotic-resistant H. pylori infection. Of these, 27 (32.5%) had bacterial strains resistant to clarithromycin, 3 (3.6%) to levofloxacin, and 4 (4.8%) to both antibiotics. Conclusion The THD fecal test has high performance for the non-invasive diagnosis of H. pylori infection while additionally enabling the assessment of bacterial antibiotic resistances.

Diagnosis of acute respiratory distress syndrome by exhaled breath analysis.

Abstract: The acute respiratory distress syndrome (ARDS) is a complication of critical illness that is characterized by acute onset, protein rich, pulmonary edema. There is no treatment for ARDS, other than the reduction of additional ventilator induced lung injury. Prediction or earlier recognition of ARDS could result in preventive measurements and might decrease mortality and morbidity. Exhaled breath contains volatile organic compounds (VOCs), a collection of hundreds of small molecules linked to several physiological and pathophysiological processes. Analysis of exhaled breath through gas-chromatography and mass-spectrometry (GC-MS) has resulted in an accurate diagnosis of ARDS in several studies. Most identified markers are linked to lipid peroxidation. Octane is one of the few markers that was validated as a marker of ARDS and is pathophysiologically likely to be increased in ARDS. None of the currently studied breath analysis methods is directly applicable in clinical practice. Two steps have to be taken before any breath test can be allowed into the intensive care unit. External validation in a multi-center study is a prerequisite for any of the candidate breath markers and the breath test should outperform clinical prediction scores. Second, the technology for breath analysis should be adapted so that it is available at a decentralized lab inside the intensive care unit and can be operated by trained nurses, in order to reduce the analysis time. In conclusion, exhaled analysis might be used for the early diagnosis and prediction of ARDS in the near future but several obstacles have to be taken in the coming years. Most of the candidate markers can be linked to lipid peroxidation. Only octane has been validated in a temporal external validation cohort and is, at this moment, the top-ranking breath biomarker for ARDS.

Hydrogen breath test to detect small intestinal bacterial overgrowth: a prevalence case–control study in autism

Abstract: The aim of this study is to assess the prevalence of small intestinal bacterial overgrowth (SIBO) by hydrogen breath test in patients with autism spectrum disorders (ASD) with respect to a consistent control group. From 2011 to 2013, 310 children with ASD and 1240 sex- and age-matched typical children were enrolled in this study to undergo glucose breath test. The study participants were considered to exhibit SIBO when an increase in H2 of ≥20 ppm or CH4 of ≥10 ppm with respect to the fasting value was observed up to 60 min after the ingestion of glucose. Ninety-six children with autism suffered from SIBO, giving a prevalence rate of SIBO was 31.0% (95% CI 25.8–36.1%). In contrast, 9.3% of the typical children acknowledged SIBO. The difference between groups was statistically significant (P < 0.0001). The median Autism Treatment Evaluation Checklist (ATEC) score in the children with autism and with SIBO was significantly high when compared with the children without autism and without SIBO [98 (IQR, 45–120) vs. 63 (32–94), P < 0.001]. For the autism group, the 6-GI Severity Index (6-GSI) score was found to be strongly and significantly correlated with the total ATEC score (r = 0.639, P < 0.0001). SIBO was significantly associated with worse symptoms of autism, demonstrating that children with SIBO may significantly contribute to symptoms of autism.

The characterisation of hepatic mitochondrial function in patients with non-alcoholic fatty liver disease (NAFLD) using the 13C-ketoisocaproate breath test.

Abstract: Hepatic mitochondrial function (HMF) assessed by the 13C-ketoisocaproate breath test (13C-KICA BT) has been previously shown to be significantly associated with the severity of biopsy proven non-alcoholic fatty liver disease (NAFLD). However, it is uncertain whether any perturbation in HMF relates specifically to severity of liver disease or factors associated with metabolic syndrome within non-alcoholic fatty liver disease (NAFLD). Our aim was to investigate whether there was any change in HMF assessed by 13C-KICA BT in patients with NAFLD compared to control subjects, and to assess the factors that are independently associated with HMF. Methods: 77 patients with NAFLD and 11 healthy control subjects were studied. HMF was assessed using 13C-KICA BT and expressed as cumulative % 13C-dose recovered on breath over 1hr (cPDR over 1hr). Liver fat and fibrosis was assessed by transient elastography. Multi-variable linear regression modelling was undertaken to test the independence of associations with HMF. Results: HMF (cPDR over 1hr) was lower in NAFLD compared to controls [13.4% (4.8) v. 21.0% (6.3); p<0.0001)]. In NAFLD, HMF was lower in patients with diabetes versus no diabetes [12.7% (3.4) v. 14.3% (6.1); p=0.003)]. Regression modelling showed age (β = -0.08; p=0.01), waist circumference (β = -0.08; p=0.01), hip circumference (β = -0.04; p=0.01), aspartate aminotransferase (AST) (β = -0.05; p=0.01) and diabetes status (β = -1.81; p=0.01) were independently associated with HMF (R2 = 41.5%; p Conclusions: In patients with NAFLD (compared to healthy subjects), there was a reduction in HMF assessed by the 13C-KICA BT. Furthermore, in patients with NAFLD, HMF is independent and inversely associated with age, waist and hip circumference, AST and diabetes status.

Does a glucose-based hydrogen and methane breath test detect bacterial overgrowth in the jejunum?

Abstract: BACKGROUND Direct diagnosis of small intestinal bacterial overgrowth (SIBO) requires the collection and culture of fluid from the jejunal lumen, with a finding of over 105 viable bacteria per mL. More often, SIBO is diagnosed indirectly, using a non-invasive test of the exhaled hydrogen and methane generated by microbial fermentation when ingested glucose reaches the jejunum. Our objective was to determine how well this breath test detects chronic overgrowth of jejunal bacteria that is unrelated to gastrointestinal surgery. METHODS Eighteen patients reporting symptoms consistent with SIBO received a glucose breath test. On a later day, the jejunal lumen was sampled via aspiration during enteroscopy. Jejunal aspirates were cultured on aerobic and anaerobic media. DNA was extracted from the same samples and analyzed by quantitative pan-bacterial PCR amplification of 16S ribosomal rRNA genes, which provided a culture-independent bacterial cell count. KEY RESULTS Combined bacterial colony counts ranged from 5.7 x 103 to 7.9 x 106 CFU/mL. DNA-based yields ranged from 1.5 x 105 to 3.1 x 107 bacterial genomes per mL. Microbial viability ranged from 0.3% to near 100%. We found no significant correlation of glucose breath test results with either the number of bacterial colonies or with the DNA-based bacterial cell counts. Instead, higher signals in the hydrogen-methane breath test were significantly correlated with a lower viability of jejunal bacteria, at a P-value of .014. CONCLUSIONS & INFERENCES The glucose-based hydrogen and methane breath test is not sensitive to the overgrowth of jejunal bacteria. However, a positive breath test may indicate altered jejunal function and microbial dysbiosis.

Association Between Small Intestinal Bacterial Overgrowth by Glucose Breath Test and Coronary Artery Disease

Abstract: A possible role of gut bacteria and their metabolic by-products in the development of coronary artery disease (CAD) is suspected. There is a lack of studies evaluating the association of small intestinal bacterial overgrowth (SIBO) with the development of CAD. To evaluate the frequency and risk factors for angiography-confirmed CAD in patients with or without SIBO. A total of 1059 patients tested for SIBO using the glucose hydrogen/methane breath test from 2006 to 2014 were evaluated. In total, 160 had coronary artery angiography and were included in the study. SIBO-positive patients were compared to SIBO-negative patients. Demographic, clinical, and laboratory variables and the presence of CAD on coronary angiography were analyzed. Patients with SIBO had a higher frequency of CAD (78.9 vs. 38.6%, p < 0.001), diabetes mellitus (40.0 vs. 22.9%, p = 0.016), chronic kidney disease (26.7 vs. 12.9%, p = 0.025), use of angiotensin conversion enzyme inhibitor/blocker (45.5 vs. 32.9%, p = 0.008), and statins (75.6 vs. 61.4%, p = 0.004). Patients with SIBO had an increased number of coronary arteries affected compared to SIBO-negative patients (1-vessel disease 67.2 vs. 32.8%, p < 0.001; 2-vessel disease 85.7 vs. 14.3%, p < 0.001; and 3-vessel disease 82.4 vs. 17.6%, p < 0.001, respectively). In the stepwise multivariate logistic regression analysis, SIBO remained an independent risk factor for CAD (odds ratio 7.18, 95% confidence interval 3.09–16.67; p < 0.001). SIBO was found to be associated with CAD and with the number of coronary arteries involved in this study from a single tertiary center. Further studies are necessary to confirm the association of SIBO with CAD. In the presence of risk factors, patients with SIBO may benefit from assessment for CAD.

Breath volatolomics for diagnosing chronic rhinosinusitis.

Abstract: Purpose Chronic rhinosinusitis (CRS) is one of the most common chronic diseases treated by primary care physicians. It is increasingly recognized that CRS and nasal polyposis (NP) comprise several disease processes with diverse causes. Hence, subgroups of sinusitis need to be differentiated so that patients can be screened appropriately and personalized medical treatment provided. Patients and methods To address this need, we use a cross-reactive nanoarray based on either molecularly modified gold nanoparticles or molecularly modified single-walled carbon nanotubes, combined with pattern recognition for analyzing breath samples. Breath samples were collected from three groups of volunteers (total 71) at the Hillel Yaffe Medical Center: CRS, NP, and control. Results Nanoarray results discriminated between patients with sinusitis and the control group with 87% sensitivity, 83% specificity, and 85% accuracy. The system also discriminated well between the subpopulations: 1) CRS vs control (76% sensitivity, 90% specificity); 2) CRS vs NP (82% sensitivity, 71% specificity); and 3) NP vs control (71% sensitivity, 90% specificity). Conclusion This preliminary study shows that a nanoarray-based breath test for screening population for sinusitis-related conditions is feasible.

Relationship Between Abdominal Symptoms and Fructose Ingestion in Children with Chronic Abdominal Pain

Abstract: Limited valid data are available regarding the association of fructose-induced symptoms, fructose malabsorption, and clinical symptoms. To develop a questionnaire for valid symptom assessment before and during a carbohydrate breath test and to correlate symptoms with fructose breath test results in children/adolescents with functional abdominal pain. A Likert-type questionnaire assessing symptoms considered relevant for hydrogen breath test in children was developed and underwent initial validation. Fructose malabsorption was determined by increased breath hydrogen in 82 pediatric patients with functional abdominal pain disorders; fructose-induced symptoms were quantified by symptom score ≥2 and relevant symptom increase over baseline. The results were correlated with clinical symptoms. The time course of symptoms during the breath test was assessed. The questionnaire exhibited good psychometric properties in a standardized assessment of the severity of carbohydrate-related symptoms. A total of 40 % (n = 33) had malabsorption; symptoms were induced in 38 % (n = 31), but only 46 % (n = 15) with malabsorption were symptomatic. There was no significant correlation between fructose malabsorption and fructose-induced symptoms. Clinical symptoms correlated with symptoms evoked during the breath test (p < 0.001, r2 = 0.21) but not with malabsorption (NS). Malabsorbers did not differ from non-malabsorbers in terms of symptoms during breath test. Symptomatic patients had significantly higher pain and flatulence scores over the 9-h observation period (p < 0.01) than did nonsymptomatic patients; the meteorism score was higher after 90 min. Fructose-induced symptoms but not fructose malabsorption are related to increased abdominal symptoms and have distinct timing patterns.

Gd-EOB-DTPA-enhanced T1 relaxometry for assessment of liver function determined by real-time 13C-methacetin breath test.

Abstract: To determine whether liver function as determined by intravenous administration of 13C-methacetin and continuous real-time breath analysis can be estimated quantitatively from gadoxetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance (MR) relaxometry. Sixty-six patients underwent a 13C-methacetin breath test (13C-MBT) for evaluation of liver function and Gd-EOB-DTPA-enhanced T1-relaxometry at 3 T. A transverse 3D VIBE sequence with an inline T1 calculation based on variable flip angles was acquired prior to (T1 pre) and 20 min post-Gd-EOB-DTPA (T1 post) administration. The reduction rate of T1 relaxation time (rrT1) and T1 relaxation velocity index (∆R1) between pre- and post-contrast images was evaluated. 13C-MBT values were correlated with T1post, ∆R1 and rrT1, providing an MRI-based estimated 13C-MBT value. The interobserver reliability was assessed by determining the intraclass correlation coefficient (ICC). Stratified by three different categories of 13C-MBT readouts, there was a constant increase of T1 post with increasing progression of diminished liver function (p ≤ 0.030) and a constant significant decrease of ∆R1 (p ≤ 0.025) and rrT1 (p 0.88). A simple regression model showed a log-linear correlation of 13C-MBT values with T1post (r = 0.57; p < 0.001), ∆R1 (r = 0.59; p < 0.001) and rrT1 (r = 0.70; p < 0.001). Liver function as determined using real-time 13C-methacetin breath analysis can be estimated quantitatively from Gd-EOB-DTPA-enhanced MR relaxometry. • Gd-EOB-DTPA-enhanced T1 relaxometry quantifies liver function • Gd-EOB-DTPA-enhanced MR relaxometry may provide parameters for assessing liver function before surgery • Gd-EOB-DTPA-enhanced MR relaxometry may be useful for monitoring liver disease progression • Gd-EOB-DTPA-enhanced MR relaxometry has the potential to become a novel liver function index

Breath methane concentrations and markers of obesity in patients with functional gastrointestinal disorders.

Abstract: BackgroundObesity is associated with changes in the intestinal microbiome and methane-producing archaea may be involved in energy homeostasis.ObjectiveThe objective of this article is to investigat...

The effect of L-rhamnose on intestinal transit time, short chain fatty acids and appetite regulation: a pilot human study using combined 13CO2/H2 breath tests.

Abstract: Background The appetite-regulating effects of non-digestible carbohydrates (NDC) have in part previously been attributed to their effects on intestinal transit rates as well as microbial production of short chain fatty acids (SCFA). Increased colonic production of the SCFA propionate has been shown to reduce energy intake and stimulate gut hormone secretion acutely in humans. Objective We investigated the effect of the propiogenic NDC, L-rhamnose, on gastrointestinal transit times using a combined 13CO2/H2 breath test. We hypothesised that L-rhamnose would increase plasma propionate leading to a reduction in appetite, independent of changes in gastrointestinal transit times. Design We used a dual 13C-octanoic acid/lactose 13C-ureide breath test combined with breath H2 to measure intestinal transit times following the consumption of 25 g d-1 L-rhamnose, compared with inulin and cellulose, in 10 healthy humans in a randomised cross-over design pilot study. Gastric emptying (GE) and oro-caecal transit times (OCTTs) were derived from the breath 13C data and compared with breath H2. Plasma SCFA and peptide YY (PYY) were also measured alongside subjective measures of appetite. Results L-rhamnose significantly slowed GE rates (by 19.5 min) but there was no difference in OCTT between treatments. However, breath H2 indicated fermentation of L-rhamnose before it reached the caecum. OCTT was highly correlated with breath H2 for inulin but not for L-rhamnose or cellulose. L-rhamnose consumption significantly increased plasma propionate and PYY but did not significantly reduce subjective appetite measures. Conclusions The NDCs tested had a minimal effect on intestinal transit time. Our data suggest that L-rhamnose is partially fermented in the small intestine and that breath H2 reflects the site of gastrointestinal fermentation and is only a reliable marker of OCTT for certain NDCs (e.g. inulin). Future studies should focus on investigating the appetite-suppressing potential of L-rhamnose and verifying the findings in a larger cohort.

Cancer breath testing: a patent review.

Abstract: Introduction: Human breath can contain thousands of volatile organic compounds (VOCs) and semi-volatile compounds that are related to metabolism and other biochemical processes. The presence of can...

The effect of Helicobacter pylori eradication on functional dyspepsia in Turkish children.

Abstract: BACKGROUND The aim of this study was to evaluate the effect of Helicobacter pylori (H. pylori) eradication on dyspepsia symptom scores in children with functional dyspepsia (FD). MATERIALS AND METHODS One hundred and fifty functional dyspeptic children (ages 8-18 years, mean: 13.3 ± 2.84 years; 30% male) were enrolled to this prospective study. Upper gastrointestinal endoscopy was performed on all patients, and the samples from the gastric antrum and corpus were obtained for the existence of H. pylori. 13 Carbon-urea breath test was performed to evaluate the eradication therapy's efficacy. The symptoms were assessed at first visit and at the 8th week and 16th week. RESULTS Forty-nine (33%) children were in the H. pylori-positive group, and 101 (67%) children were in the H. pylori-negative group. Dyspepsia symptom scores improved at 8th week in both groups (P < .05). Helicobacter pylori was eradicated in 30 patients (61%), while in the H. pylori-eradicated group, all dyspepsia symptoms' scores decreased, and in the H. pylori-uneradicated group, only three symptoms' scores decreased. Symptom scores were lower in H. pylori-eradicated group than H. pylori-uneradicated group. CONCLUSIONS Although the tests used for the diagnosis of H. pylori in functional dyspeptic patients increased the cost of health care, the dyspepsia symptom scores decreased with the eradication therapy in a high prevalence community. The findings may differ in low prevalence communities where the diagnostic tests for H. pylori infection are not recommended in children in the absence of alarm signs or symptoms.

Potential of non-invasive breath tests for preselecting individuals for invasive gastric cancer screening endoscopy.

Abstract: Background. Regular screening for gastric cancer (GC) is based on invasive upper gastrointestinal endoscopy and is limited to few high-incidence countries. As GC is a major cause of cancer death worldwide, a non-invasive, simple screening test is of value. We assessed the prevalence of preclinical GC and the corresponding numbers needed to screen (NNS) to detect GC cases both without and with preselection using breath tests from the literature in various populations. Methods. Using age- and sex-specific GC incidence data and rates of transition from preclinical to clinical GC, we estimated the prevalences of preclinical GC worldwide in populations aged 50–74 years, and we evaluated the accuracy of breath testing for GC detection based on published studies. We then derived the expected positive predictive values for breath testing in populations with different preclinical GC prevalences. Results. Four studies reporting the sensitivity and specificity of breath tests were identified, and summary estimates of 83% sensitivity and 91% specificity were derived by meta-analysis. The estimates of the overall prevalence of preclinical GC were <0.5% in men and <0.2% in women aged 50–74 years across different regions of the world. The positive predictive values, the prevalence among breath test positive people, were approximately nine-fold higher in all populations, resulting in an approximately nine-fold lower NNS to detect one GC case when breath tests were used for preselection for screening. Conclusion. Given the low prevalence of preclinical GC, non-invasive breath tests show promise for making screening more efficient. Further validation of breath tests and evidence on the rates of transition from preclinical to clinical GC are needed to validate the breath test approach.

Correlation between Quantitative 13C-Urea Breath Test and Helicobacter pylori Treatment Success in a Population-Based Cohort.

Abstract: Background. There are continual efforts to identify factors which influence the success of first-line therapy for Helicobacter pylori (H. pylori) infection. The 13C-urea breath test result (C13-UBT) utilizes H. pylori urease activity and is a highly accurate diagnostic assay. We aimed to determine whether the magnitude of C13-UBT result is related to treatment success. Methods. Adult patients who underwent a first-time 13C-urea breath test between January 2010 and January 2016 were included. In order to isolate a naive test-and-treat population who were unlikely to have undergone an initial endoscopy-based H. pylori test, we excluded patients > 45 years and those with a previous C13-UBT. Data were extracted from the Clalit Health Services laboratory database. Results. A total of 94,590 subjects (36.1% male, age 28.5 ± 6.0 years) who underwent a first-time C13-UBT during the study period were included. C13-UBT was positive in 48,509 (51.3%) subjects. A confirmatory posttreatment C13-UBT was performed in 18,375 (37.8%), and eradication was successful in 12,018 (65.4%). The mean C13-UBT recording was 20.6 ± 16.2 DOB in subjects with successful eradication and 19.5 ± 13.1 DOB in subjects with treatment failure (OR, 1.01; 95% CI 1.00-1.01, ). Among patients in the upper quintile of C13-UBT measurement, eradication was achieved in 67.6%, compared to 62.6% in the lower quintile (OR, 1.22; 95% CI 1.11-1.35, ). Subjects in the top 1 percentile (C13-UBT ≥ 70 DOB) achieved eradication in 75.0%, compared to 65.3% among subjects with C13-UBT ). Conclusions. The superiority in H. pylori eradication observed in subjects with a higher C13-UBT DOB is small but significant. Further studies should examine the physiological and microbiological basis for this finding.

Effect of Bifidobacterium infantis 35624 (Align) on the Lactulose Breath Test for Small Intestinal Bacterial Overgrowth

Abstract: Small intestinal bacterial overgrowth (SIBO) may cause symptoms in patients with abdominal bloating, distension, and gas. SIBO can be assessed using the lactulose breath test (LBT). A commonly used probiotic supplement is Align containing Bifidobacterium infantis 35624. The aim of this study was to determine the effect of B. infantis 35624 on hydrogen and methane excretion during LBT. Healthy subjects underwent LBT before and after 2 weeks of daily Align administration. Hydrogen and methane concentrations were measured for each breath sample. Results are expressed as mean ± SE and analyzed using repeated measures ANCOVA. A breath test was considered positive if hydrogen and/or methane increased > 20 ppm above baseline by 90 min of the test or if a dual hydrogen peak was present. Nineteen healthy subjects were studied. Hydrogen levels were similar pre- and post-probiotic across the 3-h study (p = 0.768). In contrast, methane levels were significantly higher with probiotic administration (p = 0.012). A rise in methane > 20 ppm was seen in three subjects pre-probiotic but six post-probiotic. Of the 19 subjects, an “abnormal” LBT pre-probiotic was present in ten subjects and during the probiotic, 13 were abnormal. This study found that 2 weeks of B. infantis 35624 (Align) supplementation affects LBT assessment for SIBO by significantly increasing methane, but not hydrogen, excretion after lactulose administration. Methane levels reached values that would be considered positive for SIBO patients. This study suggests that patients undergoing LBT should discontinue probiotics prior to the test as these supplements may alter the test results.

Hepatobiliary MRI: Signal intensity based assessment of liver function correlated to 13 C-Methacetin breath test.

Abstract: Gadoxetic acid (Gd-EOB-DTPA) is a paramagnetic MRI contrast agent with raising popularity and has been used for evaluation of imaging-based liver function in recent years. In order to verify whether liver function as determined by real-time breath analysis using the intravenous administration of 13C-methacetin can be estimated quantitatively from Gd-EOB-DTPA-enhanced MRI using signal intensity (SI) values. 110 patients underwent Gd-EOB-DTPA-enhanced 3-T MRI and, for the evaluation of liver function, a 13C-methacetin breath test (13C-MBT). SI values from before (SIpre) and 20 min after (SIpost) contrast media injection were acquired by T1-weighted volume-interpolated breath-hold examination (VIBE) sequences with fat suppression. The relative enhancement (RE) between the plain and contrast-enhanced SI values was calculated and evaluated in a correlation analysis of 13C-MBT values to SIpost and RE to obtain a SI-based estimation of 13C-MBT values. The simple regression model showed a log-linear correlation of 13C-MBT values with SIpost and RE (p < 0.001). Stratified by 3 different categories of 13C-MBT readouts, there was a constant significant decrease in both SIpost (p ≤ 0.002) and RE (p ≤ 0.033) with increasing liver disease progression as assessed by the 13C-MBT. Liver function as determined using real-time 13C-methacetin breath analysis can be estimated quantitatively from Gd-EOB-DTPA-enhanced MRI using SI-based indices.

Simultaneous detection of hydrogen and methane in breath for the diagnosis of small intestinal bacterial overgrowth by fast gas chromatography

Abstract: The hydrogen and methane breath test has been widely used in the diagnosis of SIBO (small intestinal bacterial overgrowth), which is noninvasive and convenient with good accuracy. However, most studies use commercial GC-MS to analyze breath components which requires complex operation and has a high cost, while the most common simplified devices only have a single function with some drawbacks. This study proposes a convenient, small-sized and multi-functional fast gas chromatograph (Fast GC) with a low detection limit and sufficient resolution to simultaneously determine hydrogen and methane concentrations, corrected using the carbon dioxide concentration, in breath. The system can eliminate the interference caused by dilution with outside gases, the breathing mode of the patient and other factors of alveolar gas. The detection range of the Fast GC system was 2–200 ppm, the resolution was 1 ppm, the precision was less than 10%, and the preheating time was significantly shortened to 2 hours, as well as the size being reduced to 40 cm × 30 cm × 15 cm. Two SIBO diagnostic models were established and samples from forty-seven healthy people and patients were collected and analyzed by our system. This method has the advantages of high specificity, and non-invasive and simple operation, so that it can be used for the diagnosis of increasing volumes of clinical and domestic patients.

Concordance between Lactose Quick Test, hydrogen-methane breath test and genotyping for the diagnosis of lactose malabsorption in children.

Abstract: BACKGROUND Lactose intolerance is a frequent condition in certain populations. Different methods for diagnosis exist. There is scarce literature regarding Lactose Quick Test (LQT) and concordance with other methods for lactose intolerance diagnosis in children. METHODS Prospectively, we included children who underwent gastroduodenoscopy for evaluation of abdominal pain. We obtained a duodenal sample for LQT and blood sample for genetic test to evaluate LCT C>T-13910 variant. Later, patients underwent breath test with lactose, to evaluate malabsorption. We evaluated the concordance between the three different tests. KEY RESULTS We included 46 patients, 56.5% women. Mean age was 13.2 years (range 9-18 years). 66.6% of patients had lactose malabsorption according to breath test; 64.4% were homozygous CC; and 91.3% had hypolactasia (mild or severe) according to LQT. None of the patients with normolactasia had altered breath test. Genetic test had a substantial agreement (k = 0.675) with breath test and fair agreement (k = 0.301) with LQT. LQT had fair agreement (k = 0.348) with breath test. CONCLUSIONS & INFERENCES Genetic test had better concordance with breath test than LQT to diagnose lactose malabsorption, however, none of the patients with normal LQT had lactose malabsorption. In patients who undergo gastroduodenoscopy to study abdominal pain, it seems reasonable to perform LQT, and, in those with hypolactasia, to perform breath test.

Long-term proton pump inhibitor therapy leads to small bowel bacterial overgrowth as determined by breath hydrogen and methane excretion.

Abstract: Objectives: Prolonged suppression of gastric acid secretion by proton pump inhibitors (PPIs) may alter the bacterial microbiota of the upper gastrointestinal tract and lead to small bowel bacterial overgrowth (SBBO). Published reports have shown conflicting results on the association between PPI therapy and risk of SBBO development. We evaluated whether long-term PPI treatment is associated with presence of SBBO as determined by breath hydrogen (H2) and methane (CH4) excretion. We also assessed the differences in H2 / CH4 excretion patterns in patients taking PPI compared with those not taking the medication and searched for the potential predictors of a positive breath test result. Material and methods: This was a prospective cohort study that included 67 PPI treated patients (PPIT) and 62 not-receiving PPI (C, comparison). PPIT and C underwent a glucose H2 / CH4 breath test (HMBT) to determine the presence of SBBO. Results: The prevalence of SBBO was significantly higher in PPIT compared to C (44.8% vs 21%, p=0.005, OR = 3.06, 95% CI 1.40-6.66) as determined by H2 and CH4 excretion. We found that PPIT had all H2 test parameters (baseline H2 levels, maximum peak of H2 as well as mean H2 through the whole test) significantly higher than C. Even those PPIT who did not meet criteria of breath test positivity had statistically higher breath H2 levels compared to C. Although we did not observe significant differences in CH4 excretion between groups, 19.4% of PPIT and 12.9% of C would have had a false-negative HMBT results had CH4 not been taken into account. Conclusions: Long-term PPI use was found to be significantly associated with the SBBO development as determined by breath H2 and CH4 excretion. CH4 determination reduces the number of falsely negative test results.