Showing papers on "Breath test published in 2020"

Volatile organic compounds in breath can serve as a non-invasive diagnostic biomarker for the detection of advanced adenomas and colorectal cancer.

Abstract: Background Colorectal cancer (CRC) is the third most common cancer diagnosis in the Western world. Aim To evaluate exhaled volatile organic compounds (VOCs) as a non-invasive biomarker for the detection of CRC and precursor lesions using an electronic nose. Methods In this multicentre study adult colonoscopy patients, without inflammatory bowel disease or (previous) malignancy, were invited for breath analysis. Two-thirds of the breath tests were randomly assigned to develop training models which were used to predict the diagnosis of the remaining patients (external validation). In the end, all data were used to develop final-disease models to further improve the discriminatory power of the algorithms. Results Five hundred and eleven breath samples were collected. Sixty-four patients were excluded due to an inadequate breath test (n = 51), incomplete colonoscopy (n = 8) or colitis (n = 5). Classification was based on the most advanced lesion found; CRC (n = 70), advanced adenomas (AAs) (n = 117), non-advanced adenoma (n = 117), hyperplastic polyp (n = 15), normal colonoscopy (n = 125). Training models for CRC and AAs had an area under the curve (AUC) of 0.76 and 0.71 and blind validation resulted in an AUC of 0.74 and 0.61 respectively. Final models for CRC and AAs yielded an AUC of 0.84 (sensitivity 95% and specificity 64%) and 0.73 (sensitivity and specificity 79% and 59%) respectively. Conclusions This study suggests that exhaled VOCs could potentially serve as a non-invasive biomarker for the detection of CRC and AAs. Future studies including more patients could further improve the discriminatory potential of VOC analysis for the detection of (pre-)malignant colorectal lesions. (https://clinicaltrials.gov Identifier NCT03488537).

Duodenal bacterial load as determined by quantitative polymerase chain reaction in asymptomatic controls, functional gastrointestinal disorders and inflammatory bowel disease.

Abstract: Background: Small intestinal bacterial overgrowth may play a role in gastrointestinal and non-gastrointestinal diseases. Aims: To use quantitative polymerase chain reaction (qPCR) to determine and compare bacterial loads of duodenal biopsies in asymptomatic controls, and patients with functional gastrointestinal disorders (FGIDs) and inflammatory bowel disease (IBD) including ulcerative colitis (UC) and Crohn’s disease (CD). To define effects of gastric acid inhibition on bacterial load, explore links of bacterial load and gastrointestinal symptoms in response to a standardised nutrient challenge and compare bacterial load with glucose breath test results. Methods: In 237 patients (63 controls, 84 FGID and 90 IBD), we collected mucosal samples under aseptic conditions during endoscopy extracted and total DNA. Bacterial load metric was calculated utilising qPCR measurements of the bacterial 16S rRNA gene, normalised to human beta-actin expression. Standard glucose breath test and nutrient challenge test were performed. Results: The duodenal microbial load was higher in patients with FGID (0.22 ± 0.03) than controls (0.07 ± 0.05; P = 0.007) and patients with UC (0.01 ± 0.05) or CD (0.02 ± 0.09), (P = 0.0001). While patients treated with proton pump inhibitors (PPI) had significantly higher bacterial loads than non-users (P < 0.05), this did not explain differences between patient groups and controls. Bacterial load was significantly (r = 0.21, P < 0.016) associated with the symptom response to standardised nutrient challenge test. Methane, but not hydrogen values on glucose breath test were associated with bacterial load measured utilising qPCR. Conclusions: Utilising qPCR, a diagnosis of FGID and treatment with PPI were independently associated with increased bacterial loads. Increased bacterial loads are associated with an augmented symptom response to a standardised nutrient challenge.

Use of a Novel Probiotic Formulation to Alleviate Lactose Intolerance Symptoms-a Pilot Study.

Abstract: Lactose intolerance is a common condition caused by lactase deficiency and may result in symptoms of lactose malabsorption (bloating, flatulence, abdominal discomfort, and change in bowel habits). As current data is limited, the aim of our study was to assess the efficacy of probiotics with a β-galactosidase activity on symptoms of lactose malabsorption and on the lactose hydrogen breath test (LHBT). The study group comprised eight symptomatic female patients with a positive LHBT. Patients were treated for 6 months with a probiotic formula with β-galactosidase activity (Bio-25, Ambrosia-SupHerb, Israel). All patients completed a demographic questionnaire as well as a diary for the assessment of symptom severity and frequency at entry, every 8 weeks, and at the end of the treatment period. Measurements of hydrogen (H2) levels (parts per million, ppm) at each of these time points were also performed. End points were a decrease of 50% in symptom severity or frequency, and the normalization (decrease below cutoff point of 20 ppm) of the breath test. Mean age and mean body mass index (BMI) were 36.4 ± 18.6 years and 23.2 kg/m2, respectively. Compared to baseline scores, the frequency of most symptoms, and the severity of bloating and flatulence, improved after treatment. Normalization of LHBT was obtained in only two patients (25%). In this pilot study, Bio-25, a unique formulation of probiotics with β-galactosidase activity, demonstrated symptom resolution in most patients with lactose malabsorption. A larger randomized trial is warranted to confirm these preliminary findings.

Diagnostic Utility of Carbohydrate Breath Tests for SIBO, Fructose, and Lactose Intolerance

Abstract: Unexplained bloating, gas, and pain are common symptoms. If routine tests are negative, such patients are often labeled as irritable bowel syndrome. To determine the diagnostic utility of breath tests that assess for small intestinal bacterial overgrowth (SIBO), fructose or lactose intolerance, and the predictive value of symptoms. Patients with gas, bloating, diarrhea, abdominal pain (≥ 6 months), and negative endoscopy and radiology tests were assessed with symptom questionnaires, glucose (75 g), fructose (25 g), or lactose (25 g) breath tests. Breath tests were categorized as positive when H2 (≥ 20 ppm) or CH4 (≥ 15 ppm) increased above baseline values or as hypersensitive when symptoms changed significantly without rise in H2/CH4 or as negative. 1230 patients (females = 878) underwent 2236 breath tests. The prevalence of SIBO was 33% (294/883), fructose intolerance was 34% (262/763), and lactose intolerance was 44% (260/590). Hypersensitivity was found in 16% and 9%, respectively, during fructose and lactose breath tests. Although gas (89%), abdominal pain (82%), and bloating (82%) were highly prevalent, pretest symptoms or their severity did not predict an abnormal breath test, but symptoms during the breath test facilitated diagnosis of SIBO, fructose, and lactose intolerance and hypersensitivity. Approximately 45% of patients with unexplained gas and bloating had SIBO, fructose, or lactose intolerance; another 9–16% had visceral hypersensitivity. Pretest symptoms were poor predictors, but symptoms during the breath tests were useful. Breath tests are safe, provide significant diagnostic yield, and could be useful in routine gastroenterology practice.

The correlation between breath acetone and blood betahydroxybutyrate in individuals with type 1 diabetes

Abstract: Ketone testing is an important element of the self-management of illness in type 1 diabetes. The aim of the present study was to see if a breath test for acetone could be used to predict quantitatively the levels of the ketone betahydroxybutyrate in the blood of those with type 1 diabetes, and thus be used as an alternative to capillary testing for ketones. Simultaneous capillary ketones and breath acetone were measured in 72 individuals with type 1 diabetes attending a diabetes clinic and on 9 individuals admitted to hospital with diabetic ketoacidosis. Capillary blood measurements ranged from 0.1 mmol l-1 (the lower limit of the ketone monitor) to over 7 mmol l-1, with breath acetone varying between 0.25 and 474 parts per million by volume. The two variables were found to be correlated and allowed modelling to be carried out which separated breath acetone levels into three categories corresponding to normal, elevated and 'at risk' levels of blood ketones. The results on this limited set of participants suggest that a breath acetone test could be a simple, non-invasive substitute for capillary ketone measurement in type 1 diabetes.

The peppermint breath test: a benchmarking protocol for breath sampling and analysis using GC-MS.

Abstract: Exhaled breath contains hundreds of volatile organic compounds (VOCs) which offers the potential for diagnosing and monitoring a wide range of diseases. As the breath research field has grown, sampling and analytical practices have become highly varied between groups. Standardisation would allow meta-analyses of data from multiple studies and greater confidence in published results. The Peppermint Consortium has been formed to address this task of standardisation. In the current study we aimed to generate initial benchmark values for thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) analysis of breath samples containing peppermint-derived VOCs. Headspace analysis of peppermint oil capsules was performed to determine compounds of interest. Ten healthy participants were recruited by three groups. Each participant provided a baseline breath sample prior to taking a peppermint capsule, with further samples collected at 60, 90, 165, 285 and 360 min following ingestion. Sampling and analytical protocols were different for each institution, in line with their usual practice. Samples were analysed by TD-GC-MS and benchmarking values determined for the time taken for detected peppermint VOCs to return to baseline values. Sixteen compounds were identified in the capsule headspace. Additionally, 2,3-dehydro-1,8-cineole was uniquely found in the breath samples, with a washout profile that suggested it was a product of peppermint metabolism. Five compounds (α-pinene, β-pinene, eucalyptol, menthol and menthone) were quantified by all three groups. Differences in recovery were observed between the groups, particularly for menthone and menthol. The average time taken for VOCs to return to baseline was selected as the benchmark and were 441, 648, 1736, 643 and 375 min for α-pinene, β-pinene, eucalyptol, menthone and menthol respectively. An initial set of easy-to-measure benchmarking values for assessing the performance of TD-GC-MS systems for the analysis of VOCs in breath is presented. These values will be updated when more groups provide additional data.

Evaluation of lactulose, lactose, and fructose breath testing in clinical practice: A focus on methane.

Abstract: Background and aim Breath testing (BT) is used to identify carbohydrate malabsorption and small intestine bacterial overgrowth. Measuring methane alongside hydrogen is advocated to reduce false-negative studies, but the variability of methane production is unknown. The aim of this study is to examine the effect of high methane production on hydrogen excretion after ingesting lactulose, fructose, or lactose. Methods A retrospective audit was performed of patients with gastrointestinal symptoms who underwent BT. Following a low fermentable carbohydrate diet for 24-h, a fasting BT before consuming 35 ml lactulose, 35 g fructose, or lactose in 200 ml water, followed by BT every 10-15 min for up to 3-h, was performed. A positive test was defined as a ≥20 ppm rise of hydrogen or methane from baseline. A high methane producer had an initial reading of ≥5 ppm. Breath hydrogen and methane production were measured as area under the curve. Chi-squared tests were used to compare proportions of those meeting the cut-off criteria. Results Of patients, 26% (28/106) were high methane producers at their initial lactulose test. The test-retest repeatability of methane production was high, with the same methane production status before ingesting lactose in all (70/70) and before ingesting fructose in most (71/73). Methane production was highly variable during testing, with 38% (10/26) having ≥1 reading lower than baseline. Hydrogen produced by high or low methane producers did not differ (1528 [960-3645] ppm min vs 2375 [1810-3195] ppm min [P = 0.11]). Symptoms and breath test results were not positively related. Conclusion The validity of including an increase of ≥20 ppm methane to identify carbohydrate malabsorption or small intestine bacterial overgrowth should be questioned due to the variability of readings during testing.

Development of a non-invasive exhaled breath test for the diagnosis of head and neck cancer.

Abstract: Improving the ability to identify early-stage head and neck squamous cell carcinoma (HNSCC) can improve treatment outcomes and patient morbidity. We sought to determine the diagnostic accuracy of breath analysis as a non-invasive test for detecting HNSCC. Standardised breath samples were collected from 181 patients suspected of HNSCC prior to any treatment. A selected ion flow-tube mass spectrometer was used to analyse breath for volatile organic compounds. Diagnosis was confirmed by histopathology. A binomial logistic regression model was used to differentiate breath profiles between cancer and control (benign disease) patients based on mass spectrometry derived variables. In all, 66% of participants had early-stage primary tumours (T1 and T2) and 58% had regional node metastasis. The optimised logistic regression model using three variables had a sensitivity and specificity of 80% and 86%, respectively, with an AUC for ROC curve of 0.821 (95%CI 0.625–1.0) in the testing cohort. Breath analysis for non-invasive diagnosis of HNSCC appears to be practical and accurate. Future studies should be conducted in a primary care setting to determine the applicability of breath analysis for early identification of HNSCC.

Dietary fatty acid oxidation is decreased in non‐alcoholic fatty liver disease: A palmitate breath test study

Abstract: Background & aim Hepatic fat excess in non-alcoholic fatty liver disease (NAFLD) reflects an imbalance between fat accumulation and disposal. Conflicting data exist for the role of fatty acid oxidation (FAO), one of the disposal pathways, and have mostly come from the studies delivering fatty acids (FAs) intravenously. Whether FAO of orally provided FAs is affected in NAFLD is unknown. Methods We performed a breath test study to measure FAO in subjects with NAFLD and healthy controls. Subjects ingested [1-13 C] palmitic acid (PA, 10 mg/kg) in a liquid meal and the rate of 13 CO2 appearance in expired air was measured over 6 hours by a BreathID device (Exalenz) to obtain the cumulative percent dose recovered (CPDR), the total amount of ingested 13 C recovered. CPDR was corrected by the results of a [1-13 C] acetate breath test, performed 1-4 weeks later, to calculate the rate of PA β-oxidation. Results Palmitic acid oxidation was 27% lower in 43 subjects with NAFLD compared to 11 controls (CPDR 9.5 ± 2.4% vs 13.1 ± 3.7%, P = .0001) and this persisted after correcting for acetate (29.3 ± 10.5 vs 36.6 ± 13.9, P = .03). The decrease in FAO was not because of the delayed transit as the time to peak 13 C detection did not differ between groups (4.9 ± 1.2 hours vs 4.7 ± 0.8 hours, P = .7). Rates of PA oxidation were not correlated with obesity, hepatic or adipose insulin resistance, alanine aminotransferase, liver fat content and NAFLD histology. Conclusion Fatty acid oxidation of orally delivered FA is decreased in NAFLD compared to healthy controls, likely reflecting decreased β-oxidation. The use of a breath test offers non-invasive dynamic assessment of FAO.

Increasing Expiratory Hydrogen in Lactose Intolerance Is Associated with Additional Food Intolerance/Malabsorption.

Abstract: Single and/or combined food intolerance/malabsorption may cause nonspecific, functional gastrointestinal (GI) complaints. In lactose-intolerant patients we evaluated the influence of additional food intolerance/malabsorption with hydrogen (H2) breath tests. In a retrospective analysis of charts from 279 lactose-intolerant patients, we found 128 patients with only lactose intolerance (LIT). Then, we identified 106 LIT patients with additional histamine intolerance (HIT). Additionally, 45 LIT and HIT patients also had fructose malabsorption (FM). A hydrogen (H2) breath test was performed to evaluate LIT and FM. A serum diamine oxidase value of 20 ppm increase of expiratory H2 from baseline, there were 74 LIT-only patients, 60 LIT with HIT patients, and 36 LIT patients with additional HIT and FM. With the Kruskal-Wallis test AUCs demonstrated a significant difference between all three groups (p = 0.024). In patients with LIT, the presence of additional food intolerance/malabsorption, significantly increases expiratory H2 values. We demonstrate evidence, which may suggest HIT to embody an own GI disorder as food intolerance/malabsorption.

A novel variant of the 13 C-methacetin liver function breath test that eliminates the confounding effect of individual differences in systemic CO 2 kinetics.

Abstract: The principle of dynamic liver function breath tests is founded on the administration of a 13C-labeled drug and subsequent monitoring of 13CO2 in the breath, quantified as time series delta over natural baseline 13CO2 (DOB) liberated from the drug during hepatic CYP-dependent detoxification. One confounding factor limiting the diagnostic value of such tests is that only a fraction of the liberated 13CO2 is immediately exhaled, while another fraction is taken up by body compartments from which it returns with delay to the plasma. The aims of this study were to establish a novel variant of the methacetin-based breath test LiMAx that allows to estimate and to eliminate the confounding effect of systemic 13CO2 distribution on the DOB curve and thus enables a more reliable assessment of the hepatic detoxification capacity compared with the conventional LiMAx test. We designed a new test variant (named "2DOB") consisting of two consecutive phases. Phase 1 is initiated by the intravenous administration of 13C-bicarbonate. Phase 2 starts about 30 min later with the intravenous administration of the 13C-labelled test drug. Using compartment modelling, the resulting 2-phasic DOB curve yields the rate constants for the irreversible elimination and the reversible exchange of plasma 13CO2 with body compartments (phase 1) and for the detoxification and exchange of the drug with body compartments (phase 2). We carried out the 2DOB test with the test drug 13C-methacetin in 16 subjects with chronic liver pathologies and 22 normal subjects, who also underwent the conventional LiMAx test. Individual differences in the systemic CO2 kinetics can lead to deviations up to a factor of 2 in the maximum of DOB curves (coefficient of variation CV ≈ 0.2) which, in particular, may hamper the discrimination between subjects with normal or mildly impaired detoxification capacities. The novel test revealed that a significant portion of the drug is not immediately metabolized, but transiently taken up into a storage compartment. Intriguingly, not only the hepatic detoxification rate but also the storage capacity of the drug, turned out to be indicative for a normal liver function. We thus used both parameters to define a scoring function which yielded an excellent disease classification (AUC = 0.95) and a high correlation with the MELD score (RSpearman = 0.92). The novel test variant 2DOB promises a significant improvement in the assessment of impaired hepatic detoxification capacity. The suitability of the test for the reliable characterization of the natural history of chronic liver diseases (fatty liver—fibrosis—cirrhosis) has to be assessed in further studies.

Synthesis of Interleukin-10 in Patients with Ulcerative Colitis and Helicobacter pylori Infection

Abstract: Background/Aims. Epidemiological evidence suggests a relationship between Helicobacter pylori infection with the development of autoimmune diseases. H. pylori elicit a chronic systemic inflammatory response with the secretion of proinflammatory cytokines. IL-10 is a regulatory cytokine that plays a central role in limiting host immune response to pathogen. Increased IL-10 levels were reported in H. pylori–infected gastric mucosa. The aim of this study was to explore the relationship between IL-10 systemic synthesis and H. pylori infection in patients with ulcerative colitis. Methods. Detection of H. pylori infection was performed by a 13C-urea breath test in 31 patients with UC. In each patient, a serum sample was drawn to measure IL-10 by the ELISA technique. Based on the primary breath test result, two groups were formed and serum IL-10 was measured. Results. Serological IL-10 levels in patients with UC and negative 13C-urea breath test was 10.28 pg/ml whereas in patients with UC and positive 13C-urea breath test was 5.5 pg/ml ( ). IL-10 levels were higher in the inflammatory endoscopic and histological active groups which tested positive in the 13C-urea breath tests for H. pylori ( ). Conclusions. The role of IL-10 secretion in patients with UC in determining the clinicopathological outcome of infection merits further study. This study suggests an association between serum IL-10 and disease severity in patients with UC and HP infection.

Breath Test Gas Patterns in Inflammatory Bowel Disease with Concomitant Irritable Bowel Syndrome-Like Symptoms: A Controlled Large-Scale Database Linkage Analysis

Abstract: Breath testing (BT) has gained interest for diagnosing small intestinal bacterial overgrowth (SIBO) in IBD patients with irritable bowel syndrome (IBS) overlap. We aim to characterize the rate of SIBO and BT gas patterns in IBD patients with IBS-like symptoms compared to non-IBD patients. A database of 14,847 consecutive lactulose BTs was developed from patients with IBS-like symptoms between November 2005 and October 2013. BTs were classified as normal, H2 predominant, CH4 predominant, and flatline based on criteria established from the literature. BT data linkage with electronic health records and chart review identified IBD patients along with disease phenotype, location, severity, and antibiotic response. Poisson loglinear model evaluated differences in gas patterns between the two groups. After excluding patients with repeat breath tests, we identified 486 IBD and 10,505 non-IBD patients with at least one BT. Positive BT was present in 57% (n = 264) of IBD patients. Crohn’s disease (odds ratio (OR) 0.21, [95% confidence interval (CI) 0.11–0.38]) and ulcerative colitis (OR 0.39, [95% CI 0.22–0.70]) patients were less likely to produce excess CH4. IBD patients were more likely to have flatline BT (OR 1.82, [95% CI 1.20–2.77]). In IBD patients with SIBO, 57% improved symptomatically with antibiotics. In a cohort of IBD patients with IBS-like symptoms, a high rate of patients had positive BT and symptomatic improvement with antibiotics. In IBD, methanogenesis is suppressed and flatline BT is more frequent, suggesting excess hydrogenotrophic bacteria. These findings suggest methanogenic and hydrogenotrophic microorganisms as potential targets for microbiome-driven biomarkers and therapies.

Gd-EOB-DTPA-enhanced MRI T1 relaxometry as an imaging-based liver function test compared with 13 C-methacetin breath test.

Abstract: BackgroundGadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) can be used as an imaging-based liver function test. This study aims to ...

Diagnosis of Helicobacter pylori infection in the elderly using an immunochromatographic assay-based stool antigen test.

Abstract: The diagnostic value of Helicobacter pylori stool antigen (HpSA) tests in elderly subjects remains unclear. The objective of this study was to assess the diagnostic accuracy of the immunochromatographic assay-based HpSA test in a male elderly cohort and identify factors affecting the accuracy. Data for asymptomatic elderly male citizens (≥65 years old) who received health checkups at the Chinese PLA General Hospital between July 2007 and November 2018 were collected. The diagnostic accuracy of the HpSA test was determined using the 13 C-urea breath test as a reference standard. Associations between baseline comorbidities and the accuracy of the HpSA test were analyzed. In total, 316 participants were enrolled, including 193 in the pre-treatment group (77.2 ± 7.8 years old) and 123 in the post-treatment group (78.7 ± 8.3 years old). The accuracy (91.5%, 91.2%, and 91.9%) and specificity (97.6%, 98.7%, and 96.0%) were high in all participants, pre- and post-treatment groups, respectively. However, sensitivities were only 68.7%, 65.1%, and 75.0%, respectively. In the pre-treatment group, constipation was associated with decreased sensitivity (p = 0.039), while colorectal polyps were associated with increased sensitivity (p = 0.010). Multivariate analysis indicated that constipation and colorectal polyps are independent factors for the sensitivity of HpSA in the pre-treatment group. The immunochromatographic assay-based HpSA test achieved high accuracy with high specificity but suboptimal sensitivity in the elderly male cohort. Constipation and colorectal polyps were negatively and positively associated with HpSA sensitivity, respectively, in the pre-treatment group.

Rapid Point-Of-Care Breath Test Predicts Breast Cancer And Abnormal Mammograms in Symptomatic Women

Abstract: Background Previous studies have reported volatile organic compounds (VOCs) in the breath as biomarkers of breast cancer. These biomarkers may be derived from cancer-associated fibroblasts, in which oxidative stress degrades polyunsaturated fatty acids to volatile alkanes and methylated alkane derivatives that are excreted in the breath. We evaluated a rapid point-of-care test for breath VOC biomarkers as predictors of breast cancer and abnormal mammograms. Methods We studied 593 women aged ≥ 18 yr referred to three sites for mammography for a symptomatic breast-related concern (e.g. breast mass, nipple discharge). A rapid point-of-care breath testing system collected and concentrated alveolar breath VOCs on a sorbent trap and analyzed them with gas chromatography and surface acoustic wave detection in Results Prediction of breast cancer: 50 women had biopsy-proven breast cancer (invasive cancer 41, ductal non-invasive cancer 9) Unsplit data set: Breath VOCs identified breast cancer with 83% accuracy (area under curve of receiver operating characteristic), 82% sensitivity and 77.1% specificity. Split data sets: Training set breath VOCs identified breast cancer with 80.3% accuracy, 84% sensitivity and 74.3% specificity. Corresponding values in the validation set were 68%% accuracy, 72.4% sensitivity and 61.5% specificity. Prediction of BIRADS 4 and 5 mammograms (versus BIRADS 1, 2 and 3): Unsplit data set: Breath VOCs identified abnormal mammograms with 76.2% accuracy. Split data sets: Breath VOCs identified abnormal mammograms with 74.2% accuracy, 73.3% sensitivity and 60% specificity. Corresponding values in the validation set were 60.5% accuracy, 64.2% sensitivity and 51% specificity. Conclusions A rapid point-of-care test for breath VOC biomarkers accurately predicted risk of breast cancer and abnormal mammograms in women with breast-related symptoms.

The role of small intestinal bacterial overgrowth and false positive diagnosis of lactose intolerance in southwest Hungary-A retrospective observational study.

Abstract: Background Lactose intolerance is a frequent gastrointestinal disease affecting 47% of the Eastern European population. Small intestinal bacterial overgrowth (SIBO) leads to carbohydrate malabsorption and therefore to false results during lactose breath and tolerance tests. Objectives We aimed to assess the prevalence of lactose maldigestion and intolerance in Hungary and to investigate the role of combined diagnostic method and testing for SIBO in reducing false results. Methods We retrospectively analyzed data from 264 adult symptomatic patients who underwent 50g lactose breath and tolerance tests in parallel over a one-year period at our center. A ≥20 ppm elevation of H2 or less than 1.1 mmol/l rise of blood glucose was diagnostic for lactose maldigestion. Patients with maldigestion who had symptoms during the test were defined as lactose intolerant. Patients with an early (≤90 min) significant (≥20 ppm) rise of H2 during lactose and/or lactulose breath tests were determined to have SIBO. Patients with slow/rapid oro-cecal transit and inappropriate preparation before the test were excluded. Results 49.6% of the 264 patients had lactose maldigestion, and 29.5% had lactose intolerance. The most frequent symptom was bloating (22.7%), while 34.8% of the study population and 60% of the symptomatic patients had SIBO. In 9.1% and 9.8% of the patients, the lactose breath and tolerance test alone gave false positive result compared with the combined method. SIBO was present in 75% of the false positives diagnosed with breath test only. Conclusions The prevalence of lactose intolerance is lower in Hungary compared to the Eastern European value (29.5% vs 47%), so it is worth performing a population-based prospective analysis in this area. A combination of lactose breath and tolerance tests and the careful monitoring of results (with early H2 rise, lactulose breath test, etc.) can decrease the false cases caused by e.g. SIBO.

Breath testing for the diagnosis of pancreatic disease.

Abstract: Purpose of review Pancreatic function tests are mainly used for the diagnosis of exocrine pancreatic insufficiency (EPI) in patients with pancreatic diseases or after pancreatic or gastric surgery. Breath tests evaluate not just pancreatic secretion but the digestion capacity of the pancreas. These tests are good candidates for the diagnosis of EPI as they are noninvasive, accurate and easy to apply to clinical practice. Recent findings The C-labelled mixed triglyceride (MTG) breath test has been optimized and validated against adequate reference methods for the diagnosis of EPI in patients with chronic pancreatitis and for the evaluation of the efficacy of pancreatic enzyme replacement therapy (PERT). In addition, reported C-MTG breath test results in patients with other pancreatic diseases and after pancreatic and gastric surgery support the accuracy and clinical applicability of this test. The evidence of pancreatic function breath tests with other C-labelled substrates is limited. Summary Increasing evidence supports the accuracy and clinical usefulness of the C-MTG breath test for the diagnosis of EPI and the evaluation of the efficacy of PERT in different clinical conditions. Commercial availability of this test is required for a wide clinical use. The use of optimized and validated breath test protocols is mandatory.

First intraoperative measurement of liver functional capacity during liver surgery using the 13 C-methacetin breath test: early results of a pilot study.

Abstract: Highlight Postoperative liver failure remains one of the most dreadful complications of modern liver surgery. In search of a "real-time" measurement of liver functional capacity, Makridis and colleagues explored the intraoperative application of the 13C-methacetin breath test during major liver resection and report the preliminary results of this pilot study.

The 1-13 C galactose breath test in GALT deficient patients distinguishes NBS detected variant patients but does not predict outcome in classical phenotypes.

Abstract: Classical galactosemia (CG) patients frequently develop long-term complications despite early dietary treatment. The highly variable clinical outcome is poorly understood and a lack of prognostic biomarkers hampers individual prognostication and treatment. The aim of this study was to investigate the association between residual galactose oxidation capacity and clinical and biochemical outcomes in CG patients with varying geno- and phenotypes. The noninvasive 1-13C galactose breath test was used to assess whole body galactose oxidation capacity. Participants received a 7 mg/kg oral dose of 1-13C labelled galactose. The galactose oxidation capacity was determined by calculating the cumulative percentage dose of the administered galactose (CUMPCD) recovered as 13CO2 in exhaled air. Forty-one CG patients (5–47 years) and four adult controls were included. The median galactose oxidation capacity after 120 minutes (CUMPCDT120) of 34 classical patients (0.29; 0.08–7.51) was significantly lower when compared to two homozygous p.Ser135Leu patients (9.44; 8.66–10.22), one heterozygous p. Ser135Leu patient 18.59, four NBS detected variant patients (13.79; 12.73–14.87) and four controls (9.29; 8.94–10.02). There was a clear correlation between Gal-1-P levels and CUMPCDT120 (P < .0005). In the classical patients, the differences in CUMPCDT120 were small and did not distinguish between patients with poor and normal clinical outcomes. The galactose breath test distinguished classical patients from homo- and heterozygous p.Ser135Leu and NBS detected variant patients, but was not able to predict clinical outcomes in classical patients. Future studies are warranted to enable individualised prognostication and treatment, especially in NBS variants with galactose oxidation capacities in the control range.

The role and diagnostic value of the most common methods for diagnosing Helicobacter pylori infection

Abstract: The purpose of the study was to identify and evaluate the practical value of the most common diagnostic methods for Helicobacter pylori infection in patients with chronic inflammation of the gastric mucosa. Materials and methods. The study involved 104 people. All the patients examined underwent esophagogastroduodenoscopy with a rapid urease histochemical test for Helicobacter pylori and a standard five-point biopsy of the gastric mucosa for morphological evaluation and bacterioscopy. If the result of the quick urease histochemical test coincided with the data of the biopsy study on Helicobacter pylori , no further examination was carried out. In case of discrepancy the patients additionally underwent the 13 C-urease breath test. Results. It was found that the sensitivity of the rapid urease histochemical test in the area of the proposed model, according to our study, was 89.74% and the specificity was 46.15% when validating it using the additional methods. Similar calculations for the diagnostic method of staining by Giemsa showed sensitivity of 100% and specificity of 97.4%. The total number of the infected in the survey was 78 out of 104 people, which amounted to 75%. When analysing the severity of activity, inflammation and atrophic changes in the gastric mucosa, it was found that in the patients with two positive tests, the severity of the processes was significantly higher than in those with one positive test or all the tests were negative ( p < 0.05). When comparing the same processes in cases where only a quick urease histochemical test was positive and no signs of Helicobacteriosis were detected in any test, no significant differences were detected. Discussion. The rapid urease histochemical test showed good sensitivity of 89.74%, but unsatisfactory specificity of 46.15%, which severely limits its use. An unexpected result for this methodology was a large number of false positive tests, while the European recommendations indicate a more frequent occurrence of false negative results, which can be explained by differences in the production technology of the test systems. High sensitivity and specificity of the Helicobacter pylori test using Giemsa staining strongly depends on observing the methodology and experience of a specialist and cannot be recommended as a standard in the routine medical use. The study confirmed the recommendations for using at least two diagnostic tests to diagnose the infection, while the most common rapid urease histochemical test always needs confirmation. As a result of the analysis, it can be said that esophagastroduodenoscopy with a rapid urease histochemical test for Helicobacter pylori and standard diagnostic biopsy is the optimal method for diagnosing the pathology of the “upper” sections of the gastrointestinal tract. Moreover, 13 C-UDT seems to be almost ideal as a screening technique and for evaluating treatment in cases where endoscopic monitoring is not necessary.

Association between increased breath hydrogen methane concentration and prevalence of glucose intolerance in acute pancreatitis.

Abstract: Pancreatic damage, in the form of pancreatitis, intestinal bacteria and glucose imbalance could be interrelated. The aim of this study was to investigate the breath hydrogen (H2) and methane (CH4), which can indicate small intestinal bacterial overgrowth (SIBO) status, and assess the link between SIBO and glucose tolerance in patients with acute pancreatitis (AP). This prospective study enrolled 75 patients who were admitted for AP. A glucose breath test (GBT) which detects breath hydrogen H2 and CH4 for SIBO with an oral glucose tolerance test (OGTT) for 120 min was simultaneously performed to determine SIBO and glucose tolerance. Patient demographic data, laboratory test data, and computed tomography severity index (CTSI) were also evaluated. The levels of total breath H2 and CH4 in patients with AP were significantly higher than those in controls, respectively (p < 0.01). There were no significant differences in the incidence of SIBO between patients with AP and controls. The OGTT indicated that blood glucose levels at 30, 60, 90, and 120 min were higher in SIBO-positive patients than in SIBO-negative patients. No significant differences in CTSI, patient demographic data or laboratory test data were observed between the two groups. Breath H2 and CH4 concentrations are relatively higher in patients with AP, indicating a correlation between high levels of intestinal bacteria and AP. Furthermore, higher breath H2 and CH4 concentrations appear to be associated with oral glucose intolerance, with hyperglycemia occurring in patients with AP.

Small Intestinal Bacterial Overgrowth Diagnosed by a Breath Test and Improved by Rifaximin in a Patient with Hepatic Encephalopathy and Alcoholic Liver Cirrhosis: A Case Report

Abstract: A 66-year-old Japanese man was admitted to our hospital with grade 2 hepatic encephalopathy (HE). Abdominal computed tomography and laboratory examinations revealed decompensated liver cirrhosis. Intravenous administration of branched-chain amino acids immediately ameliorated the HE, and lactulose was initiated. However, a breath test revealed small intestinal bacterial overgrowth (SIBO); therefore, rifaximin was additionally initiated. The breath test was repeated after discharge, when no evidence of SIBO or overt HE was identified. This case suggested that a breath test is effective for the identification of SIBO and that the administration of a poorly absorbed antibiotic should be considered in SIBO-positive HE patients taking lactulose.

Aminopyrine breath test predicts liver‐related events and death in HCV‐related cirrhosis on SVR after DAA therapy

Abstract: BACKGROUND & AIMS In patients with hepatitis C virus (HCV)-related advanced cirrhosis, the effects of sustained virological response (SVR) by direct antiviral agents (DAAs) on decompensation and liver deaths are less clearcut, since up to 30% of patients do not improve, and no predictors of outcome have been identified. We used 13 C-aminopyrine breath test (ABT) to assess whether its changes can predict liver-related outcomes after DAA treatment in patients with HCV cirrhosis. METHODS Fifty consecutive patients with HCV cirrhosis were enrolled. Patients were included if they had Child A cirrhosis at risk for decompensation - defined as Child A6 (N = 22, 44%) or previous decompensation (N = 7, 14%) - or Child B cirrhosis (N = 21, 42%) eligible for DAA-based antiviral therapy. ABT was performed at baseline and 12 weeks after the end of antiviral therapy. Patients received sofosbuvir-based regimens. RESULTS Aminopyrine breath test was available for all 50 patients at baseline. The 120' cumulative dose was directly associated at regression analysis only with albumin levels (P = .001). ABT was available at follow-up week 12 for 41 patients (FUW12), all with SVR, and followed for a median of 25.2 months (range 12.2-32.1 months). Lower Ʌ ABT - defined as changes of 120' cumulative dose from FUW12 to baseline - (HR 0.97, 95% CI 0.94-0.99; P = .02) and FUW12 hepatic encephalopathy (HR 19.0, 95% CI 1.16-310.3; P = .03) were the only independent predictors of liver events/death at multivariate Cox regression analysis. The AUC of Ʌ ABT was good (0.87, 95% CI 0.75-0.97), with a delta ≥0% well discriminating patients at lower vs patients at higher risk of liver-related events/death (P < .001). CONCLUSIONS In patients with advanced HCV cirrhosis who achieve SVR with DAA, Ʌ ABT assists in assessing the residual likelihood of liver-related events and deaths after viral cure.

Irritable bowel syndrome and small intestinal bacterial overgrowth: Assessment with breath test

Abstract: Background: Irritable bowel syndrome (IBS) has been considered a functional disease, however evidences suggest organic abnormalities as disbiosis. The aim of this study was to evaluate bacterial overgrowth syndrome in IBS patients. Methods: Patients with IBS were submited to the expired H2 and CH4 breath test, with analyzes of exhaled air in fasting (zero minutes) and after the administration of 10g of lactulose, at times: 15, 30, 60, 90, 120, 150 and 180 minutes. The test was considered positive when the values of H2 or CH4 at 90 minutes were 20 ppm above baseline values.