Breath Hydrogen Analysis Research Articles

Highly Sensitive and Selective Detection of Hydrogen Using Pd-Coated SnO2 Nanorod Arrays for Breath-Analyzer Applications.

We report a breath hydrogen analyzer based on Pd-coated SnO2 nanorods (Pd-SnO2 NRs) sensor integrated into a miniaturized gas chromatography (GC) column. The device can measure a wide range of hydrogen (1–100 ppm), within 100 s, using a small volume of human breath (1 mL) without pre-concentration. Especially, the mini-GC integrated with Pd-SnO2 NRs can detect 1 ppm of H2, as a lower detection limit, at a low operating temperature of 152 °C. Furthermore, when the breath hydrogen analyzer was exposed to a mixture of interfering gases, such as carbon dioxide, nitrogen, methane, and acetone, it was found to be capable of selectively detecting only H2. We found that the Pd-SnO2 NRs were superior to other semiconducting metal oxides that lack selectivity in H2 detection. Our study reveals that the Pd-SnO2 NRs integrated into the mini-GC device can be utilized in breath hydrogen analyzers to rapidly and accurately detect hydrogen due to its high selectivity and sensitivity.

Hydrogen Sensing Properties of Co-Doped ZnO Nanoparticles

In this study, the gas sensing properties of Co-doped ZnO nanoparticles (Co-ZnO NPs) synthesized via a simple sol-gel method are reported. The microstructure and morphology of the synthesized Co-ZnO NPs were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. Co-ZnO NPs were then used for developing a conductometric gas sensor for the detection, at mild temperature, of low concentration of hydrogen (H2) in air. To evaluate the selectivity of the sensor, the sensing behavior toward some VOCs such as ethanol and acetone, which represent the most important interferents for breath hydrogen analysis, was also investigated in detail. Results reported demonstrated better selectivity toward hydrogen of the Co-ZnO NPs sensor when compared to pure ZnO. The main factors contributing to this behavior, i.e., the transition from n-type behavior of pristine ZnO to p-type behavior upon Co-doping, the modification of oxygen vacancies and acid-base characteristics have been considered. Hence, this study highlights the importance of Co doping of ZnO to realize a high performance breath hydrogen sensor.

呼気中水素分析による朝食内容の検討

After having investigated the actual situation of the breakfasts of 122 young women, the breath hydrogen (H2) excretion and subjective symptoms were measured during expiration for six hours after the meal intake (the three kinds of examinations meals, A: rice meal, B: bread meal, C: cereals meal) in healthy humans for the purpose of clarifying the effectiveness of the breakfast meal. The subjects of the breath hydrogen analysis were nine young healthy women. The examinations meal A (A) had a greater intake and quantity of dietary fiber than the other test meals, and a stomach colon reflection occurred earlier, and the total breath H2 quantity was significantly higher. The small intestine transit time for A was 145±17 min, B was 297±22 min, and C was 208±18 min. The significant difference was seen between A and B (p＜0. 001), A and C (p＜0. 05), and B and C (p＜0. 05) . The blood sugar was not influenced by the meal. The feeling of hunger of A became stronger than the feeling of a full stomach from 210-225 minutes. However, the feeling of a full stomach of B at the same level as acalories-in disappeared sooner. In other words, the meal with more carbohydrates was able to provide a feeling of a full stomach that lasted for a long time. The A food consisting of soup, three side dishes and rice contains more dietary fiber and produces more H2 , and it is thought that H2 is involved in the removal of the active oxygen. The rice meal for the breakfast is regarded as an effective meal for increasing the breath H2 production.

21pm3-PM007 熱電型マイクロセンサによる健常人の呼気水素ガス濃度分析

21pm3-PM007 熱電型マイクロセンサによる健常人の呼気水素ガス濃度分析

Chronic Diarrhea in Children

Chronic Diarrhea in Children

Sensing performance of thermoelectric hydrogen sensor for breath hydrogen analysis

We studied the sensing performance of the thermoelectric hydrogen sensor (THS) aimed at application to the human breath hydrogen (H 2) analysis for the evaluation of colonic flora. The THS has unique gas sensing performance such as H 2 selectivity and immunity to humidity. We have designed a simple human breath analysis system with this sensor, gas pump and dehumidifier of silica gel. The humidity of the human breath gas was controlled to be as low as 20% RH at 25 °C through the gas-drying tube because the humidity in the human breath gas causes serious noise effect. The THS system was able to detect 4–103 ppm of H 2 in human breath sample which coexisted with various gases such as methane (CH 4) and carbon monoxide (CO).

A Comparison of a Portable Breath Hydrogen Analyzer with the Quintron SC Breath Analyzer in Measuring Small Intestinal Bacterial Overgrowth

A Comparison of a Portable Breath Hydrogen Analyzer with the Quintron SC Breath Analyzer in Measuring Small Intestinal Bacterial Overgrowth

Effect of lactase preparations in asymptomatic individuals with lactase deficiency--gastric digestion of lactose and breath hydrogen analysis.

We compared two lactase preparations derived from Aspergillus orizae (AOL) and Penicillinase multicolor (PML) for stability in the stomach and overall enzymatic activity in 10 asymptomatic subjects with lactase deficiency. The subjects were given 10,000 FCC units of either AOL or PML 30 min prior to or simultaneously with 300 ml of milk. Gastric juice was withdrawn through a nasogastric tube immediately after and every 15 min for 60 min, and breath was sampled before and every 15 min for 6 h after the milk ingestion. When lactase was given simultaneously with the milk, gastric juice lactase activity and galactose concentration were significantly higher than the control levels. When lactase preparations were given 30 min prior to the milk, neither lactase activity nor galactose was detected in the gastric juice. The pH of the gastric juice was about 6.0 after the milk ingestion. Breath hydrogen did not increase when milk was ingested simultaneously with enzymes, but did increase if enzymes were given 30 min prior to milk ingestion. There were no significant differences in lactase activity, galactose concentration in gastric juice, or breath hydrogen when AOL and PML were compared. In conclusion, with exogenous lactase, digestion of lactose begins in the stomach when pH is raised to 6.0 by the buffering action of milk. Lactase preparations are effective assessed by breath hydrogen analysis in asymptomatic individuals with lactase deficiency if the enzymes are given simultaneously with milk.

Analysis of the breath hydrogen test for carbohydrate malabsorption: validation of a pocket-sized breath test analyser.

To assess the validity and clinical application of a hand-held breath hydrogen (H2) analyzer (BreatH2, Europa Scientific, Crewe, UK). Breath samples of patients referred to the Gastroenterology Unit, Women's and Children's Hospital, North Adelaide, South Australia, for confirmation of the diagnosis of carbohydrate malabsorption were analysed with the Quintron microlyzer (Quintron Instrument Co., Milwaukee, USA) and the BreatH2 analyser, using the Quintron microlyzer as the gold standard. Twenty-nine breath H2 tests (BHT) were performed in 29 patients aged 2 months to 61 years. The sensitivity and specificity of the BreatH2 analyser in detecting a positive BHT using the Quintron microlyser as the gold standard were 0.90 and 0.95 with positive and negative predictive values of 0.90 and 0.95, respectively. There was one false positive and one false negative reading. Bland-Altman plots showed a high degree of agreement between the values obtained with two different methods. The diagnosis of carbohydrate malabsorption, using a portable breath H2 analyser (BreatH2), achieved an acceptable degree of sensitivity and specificity, enabling it to be used where no alternative is available.

Lactose malabsorption: use of breath hydrogen test and serum glucose analyses in diagnostics

Background: The incidence of lactose intolerance in Finnish population is about 17%. Use of milk and milk products is common in Finland. Thus, lactose malabsorption and symptoms caused by it are familiar in outpatient clinic. Lactose absorption tests, determinations of breath hydrogen excretion and serum glucose concentration are used to detect lactose malabsorpuon after mgesnon of 50g lactose. Aims: To compare results of breath hydrogen test and serum glucose analysis in detection of lactose malabsorption. Patients: 36 patients with abdominal symptoms participated the study. Methods: Patients in fasting state ingested 50g of lactose colored with carmine red. Blood glucose was analyzed at baseline, and 20 and 40 min after its ingestion. A rise of blood glucose less than 1.1 mmollL was the limit value of an abnormal result, a rise 1.1-1.6 mmollL was considered as a borderline value. Breath hydrogen was determined with Micro H2analysator (Micro Medical Ltd.) at baseline, and 30, 60, 90 and 120 min after ingestion of lactose liquid. Exhaled hydrogen over 20ppm was determmed as posittve for lactose malabsorption. Patients' symptoms (bloating, flatulence, abdominal pain, nausea, diarrhea) during a period of 6 hours and lactose transit time were registered using a questionnaire. Results: In 7 patients, blood glucose rose less than 1.1 mmollL. Only 4 (57%) of these 7 patients had a positive breath test, the other 3 (43%) remained negative. In 13 patients rise of blood glucose was between 1.1 and 1.6mmollL, in I of these 13 patients (8%) the breath test was positive. The other 20 patients remained negative in the both tests. Due to incomplete data, 8 patients were excluded from the analysis. There was no correlation between result in lactose tolerance test (blood glucose analysis) and any of the registered symptoms or lactose transit time. Discussion and Conclusions: Results of the two used lactose absorption tests were unexpectantly dissimilar. In adult patients the breath hydrogen analysis is not suitable for diagnostics of lactose malabsorption.

Lactose digestion capacity and perceived symptomatic response after dairy product consumption in Tokelau Island migrants.

When lactose-malabsorbing individuals use dairy products decreased lactase activity and the subsequent reduction in hydrolysis of ingested lactose can result in gastrointestinal and gaseous symptoms (lactose intolerance). This article examines lactose malabsorption, perceived gastrointestinal symptoms, and dairy product consumption in a Tokelau Island migrant population in New Zealand. Questionnaire data were collected and lactose digestion capacity was determined for 58 individuals 15-71 years of age. Additional questionnaire data were collected for 137 Tokelau migrants, 18-50 years of age. Breath hydrogen analysis indicated that 63.8% (CI = 51.4-76.2%) of Tokelau migrants were lactose malabsorbers, while 22.4% (11.7-33.1%) can absorb lactose [results are inconclusive for 13.8% (4.9-22.7%) of the population]. This was consistent with results reported for other Polynesian populations. Tokelau Island migrants reported relatively low levels of gastrointestinal distress after the consumption of daily products. Less than 50% of those with lactose malabsorption perceived gastrointestinal symptoms after a 50 g of lactose in 300 ml of water, while one third of this group reported symptoms after approximately 240 ml (one glass) or less of milk. However, without confirmation by double-blind studies, it is difficult to state the extent to which symptoms are actually due to lactose. Neither the ability to absorb lactose nor perceived gastrointestinal symptoms are associated with the frequency or quantity of dairy product consumption (P > 0.05). Patterns of dairy product consumption are just as likely due to other physiological, psychological, cultural, and social factors. Am. J. Hum. Biol. 9:233-246, 1997. © 1997 Wiley-Liss, Inc.

Breath hydrogen analysis in patients with ileoanal pouch anastomosis.

The possible influence on functional outcomes of hydrogen production in the ileoanal pouch after restorative proctocolectomy was investigated by means of lactulose H2 breath tests. Eight of 15 patients had significant increases in breath hydrogen after 10 g lactulose. One patient declined to participate in further investigations, the remaining seven responders had no evidence of small bowel bacterial overgrowth after glucose H2 breath tests. The ability to produce hydrogen by anaerobic fermentation of lactulose in the pouch was unrelated to the age of the patients or of the pouch. Seven of eight responders had successive breath tests after ingestion of lactulose 20 g and wheat starch 100 g. Five of seven had significant increases after lactulose but none after wheat starch. The overall function of the pouch continence, spontaneity of defecation, and 24 hour stool frequency was significantly better in responders than in non-responders. The absence of H2 production of 100 g wheat starch may indicate either increased absorption or defective fermentation.

Chemotherapy-induced lactose intolerance in adults.

Anorexia and weight loss contribute to the morbidity and mortality from cancer. This study was designed to test the hypothesis that chemotherapy produces lactose intolerance which could have an adverse effect on the nutritional status of patients receiving cytotoxic drugs. Twenty-seven patients were evaluated for the development of lactose intolerance during chemotherapy. Lactose breath hydrogen testing (LBHT) was used to assess lactose malabsorption objectively. This test is based on the principle that in patients with lactase deficiency, lactose is not hydrolyzed in the small intestine and ultimately is degraded by colonic bacteria. This results in the production of hydrogen gas, which is excreted by the lungs and can be quantified with a breath hydrogen analyzer. Of the 27 patients studied, 8 (30%) had an abnormal postchemotherapy LBHT results, and for the population as a whole, postchemotherapy LBHT values were significantly greater than prechemotherapy values (P = 0.04). However, only three patients (11%) showed clinical symptoms of lactose intolerance during the post-chemotherapy LBHT. Five patients had asymptomatic elevations in breath hydrogen excretion on prechemotherapy testing. One of these patients had a further increase in hydrogen excretion on Day 8 after chemotherapy, which was accompanied by symptoms of lactose intolerance. Twenty-two patients had normal prechemotherapy LBHT results. Two of these patients had abnormal post-chemotherapy LBHT results, which were associated with symptoms of lactose intolerance. Although chemotherapy may interfere with lactose metabolism, the development of symptomatic lactose intolerance is uncommon. Dietary restriction of milk products in patients receiving chemotherapy therefore is not warranted unless clinical symptoms of lactose intolerance are observed.

Development of malabsorption and nutritional complications in simian immunodeficiency virus-infected rhesus macaques

To assess the development and cause of malabsorption in rhesus macaques following experimental simian immunodeficiency virus (SIV) infection and to evaluate its impact on nutritional status. Clinical malabsorption tests and serial jejunal aspirates and biopsies were obtained from nine SIV-infected and three uninfected animals prior to infection and at 1, 2, 4, 8, 12, 24, 40 and 52 weeks postinoculation. Malabsorption was measured by sucrose breath hydrogen (H2) analysis and blood assay of D-xylose. Digestive enzyme activity was determined in jejunal mucosal homogenates. Bacterial and protozoal flora were determined in jejunal aspirates. Nutritional assessment was evaluated using specific blood micronutrient values. Cellular targets of SIV in the jejunum were determined by combined in situ hybridization and immunohistochemistry. Eight out of nine SIV-infected monkeys, including asymptomatic animals, exhibited malabsorption by either increased breath H2 and/or decreased blood D-xylose. All animals that died of AIDS had diarrhea, D-xylose malabsorption and decreased sucrase activity. Significant changes in nutritional status were associated with malabsorption. Bacterial overgrowth was not considered to be a cause of malabsorption. Histopathological biopsy findings included dilated villus lacteals, excessive cellular debris, lymphoplasmocytic infiltrates and cytoplasmic vacuoles in crypt epithelial cells. SIV-infected T cells and macrophages were detected as early as 1 week postinoculation. SIV-associated malabsorption can occur prior to clinical complications of disease. Severe intestinal complications are associated with malabsorption and malnutrition in the terminal stages of AIDS. The high proportion of macaques experiencing malabsorption without detectable pathogens, suggests an enteropathogenic role for SIV.

Prevalence of lactose maldigestion. Influence and interaction of age, race, and sex.

Ninety-eight adults ranging from 20 to 89 years in age (52 blacks, 46 whites, 48 males, 50 females) were tested for lactose maldigestion by breath hydrogen analysis after consuming milk containing 16.5 g lactose (360 ml milk). Older adults (> or = 50 years) displayed a significantly higher incidence (46%) of lactose maldigestion than younger adults (< 50 years, 26%). In younger adults there were 2.4 times more maldigesters in blacks than in whites, while in older groups this ratio was 3.6. Level of breath hydrogen significantly increased with age up to the age group of 60-69 years. The interaction between age groups and race was highly significant. Of the maldigesters, 63% reported symptoms and 3% of the total sample reported severe symptoms. Results of this study indicate that the prevalance of lactose maldigestion significantly increases with age in blacks compared to whites and that the magnitude of the problem may be greater in black maldigesters than in white maldigesters.

Lactose maldigestion and milk intolerance in healthy Greek schoolchildren

The prevalence of lactose maldigestion in Greek adults is 75% but the age at which the lactase activity starts declining is not known. The prevalences of lactose maldigestion and intolerance were investigated in 150 randomly selected Greek children 5-12 y old by using breath-hydrogen analysis after ingestion of lactose (2 g/kg body wt, maximum 50 g) or 0.240 L of milk. Prevalence of lactose maldigestion increased with age (y = -7.30 + 6.49x, r = 0.88, P = 0.004), being 29.4% and 80.0% at ages 5 and 12 y, respectively. Before testing, the reported prevalences of milk-related symptoms by children with high and low lactose-digestion capacity were 21.1% and 39.7% (chi 2 = 5.96, P = 0.015), respectively. However, the corresponding prevalences of lactose intolerance after ingestion of milk were 7.3% and 8.6% (chi 2 = 0.1, P = 0.72) and only three children had a delta H2 greater than or equal to 20 ppm postprandially. Although intestinal lactase activity declines before age 5 y and many Greek children report milk-related symptoms, true malabsorption and intolerance of lactose after a glass of milk is rarely seen at this age.

Prevalence of Primary Adult Lactose Malabsorption in the Eastern Province of Saudi Arabia

Although it has been reported that adult lactose malabsorption (ALM) is relatively common among Arabs, data on the prevalence of ALM in the Saudi and Yemeni populations are scant. We have determine...

The effect of pharmacological modification of gastric emptying and mouth‐to‐caecum transit time on the absorption of sugar probe marker molecules of intestinal permeability in normal man

The present study examined the hypothesis that altered motility of the gastrointestinal tract affects absorption of probe markers of intestinal permeability. Seven healthy subjects, aged 32-44 years, received saline, 600 micrograms atropine or 10 mg metoclopramide in randomized order at weekly intervals. After 10 min they ingested a test solution containing 5 g lactulose, 5 g mannitol and 2 g 3-O-methyl glucose in 100 ml tap water. The molarity of the solution was 542 mmol l-1 and the dose administered was 80 ml m-2 body surface area. Gastric emptying was measured by ultrasound, mouth-to-caecum transit time by breath hydrogen analysis and sugar concentrations by gas-liquid chromatography. Gastric emptying half-times (min) were [mean (95% confidence intervals)] 14.9 (11:4-18.5) after saline, 22 (18.7-25.2) after atropine and 10.3 (7.0-12.6) after metoclopramide (P less than 0.002). Transit times (min) were 68.9 (52-85.2) after saline, 143 (126-159) after atropine and 38 (21.2-54.5) after metoclopramide; P less than 0.0001. Analysis of plasma levels of mannitol and 3-O-methyl glucose showed a significant within-subject effect of drug with time (P less than 0.03). Urinary excretion of mannitol in the first 5 h after ingestion of the test solution was 1256 (974-1620) mg after saline, 1560 (1210-2013) mg after atropine and 955 (740-1232) mg after metoclopramide (P less than 0.03). There were no significant differences in lactulose and 3-O-methyl glucose urinary excretion between drug treatments.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of breakfast cereals on short-term food intake

We evaluated the effect of high-fiber cereals on short-term food intake. At 0730, 14 subjects ingested one of five cereals, plus milk and orange juice. At 1100 they were presented with a buffet lunch. There was a significant inverse correlation between fiber content of the cereals and energy intake at lunch. In a second study subjects ingested a very-high-fiber (VHF) cereal or a very-low-fiber (VLF) cereal. Fewer kcalories were ingested at lunch after ingestion of the VHF cereal than after ingestion of the VLF cereal. The degree of colonic microbial fermentation of the various cereals was evaluated by breath-hydrogen analysis. The higher-fiber cereals resulted in greater hydrogen production; however, this may not influence energy intake. The results of questionnaires that asked about hunger indicated that food intake can be reduced without the perception of feeling less hungry. Thus, we found that cereals containing relatively large quantities of dietary fiber may decrease short-term food intake.

Carbohydrate fermentation by gut microflora in preterm neonates.

To study organic acid excretion, urine was collected from 52 preterm infants at weekly intervals and analysed by capillary gas chromatography-mass spectrometry. Twelve of 22 babies born before 33 weeks' gestation excreted 2,3-butanediol, as did six born between 33 and 36 weeks. Six very immature babies also excreted acetoin, the metabolic precursor of the diol. Other products derived from carbohydrate included methylmalonic and ethylmalonic acids in one baby, and D-lactic acid in five. Acetoin has never been found in urine before, and the other four acids have been found only rarely. Excretion of these metabolites by preterm babies can be explained by increased intestinal permeability, unabsorbed lactose in the colon, and colonisation with certain opportunistic micro-organisms prevalent in neonatal units, including klebsiella, serratia, and enterobacter. The findings support evidence from breath hydrogen analysis that carbohydrate fermentation takes place in the gut of preterm infants.