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Background Pancreatic exocrine insufficiency (PEI) is associated with the outcome of pancreatic disease. However, there is no method for assessing PEI that can be used noninvasively and easily for outpatient. It has been reported that changes in intestinal bacteria caused by PEI may increase breath hydrogen concentration (BHC) levels during glucose or lactose loading. We have evaluated the usefulness of fasting breath hydrogen concentration (FBHC) measurement without glucose loading for the evaluation of PEI. Methods Sixty patients underwent FBHC measurement, BT-PABA testing, and microbiome analysis. They were classified into PEI group (PABA excretion rate Results FBHC levels was higher in the PEI group 15.70 (1.4 to 77.0) ppm than in the non-PEI group 2.80 (0.7 to 28.2) ppm (P P P P Clostridium (P Conclusion FBHC shows good potential as a simple and repeatable test for the diagnosis of PEI. The elevated FBHC levels may be caused by hydrogen-producing bacteria such as Clostridium.

Obesity is a leading public health problem throughout the world. The development of foods that increase satiety and reduce food may aid weight management. This study determined the effect of consuming soluble fiber dextrin (SFD) on appetite, appetitive hormones, breath hydrogen and food intake in adults. Forty-three participants completed this study. For each treatment, 50% of the SFD was provided in liquid form as part of breakfast and 50% in solid form as a morning snack. Appetite questionnaires, blood and breath samples were collected immediately before breakfast and at regular intervals during the test session. The participants consumed an ad libitum lunch meal, afternoon snack and dinner meal, and the amount eaten was recorded. Following dinner, participants left the laboratory but were required to keep a diet diary for the remainder of the day. Breath hydrogen concentration was significantly higher following the consumption of SFD compared to control (p &lt, 0.05). There was no observed overall treatment effect of consuming SFD on GLP-1 (Glucagon-Like-Peptide-1), ghrelin, CCK-8 (Cholecystokinin) or PYY3-36 (Petptide YY) (p &gt, 0.05). Moreover, consuming foods containing SFD had no effect on subjective appetite or food intake (p &gt, 0.05). Consuming foods containing SFD increased breath hydrogen but did not influence food intake, appetite or appetitive hormones. However, the limitations of this study may have individually or collectively masked an effect of SFD on food intake and appetite.

Fifty patients undergoing hydrogen and methane breath testing at Cedars-Sinai GI Motility Lab were recruited, and consented to having their breath tested for alcohol using the EC/IR II (Intoximeter...

Long-term problems with faecal incontinence occur in up to 50 % of patients after pull-through for Hirschsprung disease (HSCR). The cause often remains unknown, leading to empirical treatments. Using nuclear transit study, we found some patients surprisingly had rapid proximal colonic transit, suspicious of occult diarrhoea. We aimed to assess whether these patients had unrecognized adverse reactions to food. Patients (n = 10, all males, 9.6 year; 4.25–15.5 years) with persistent faecal incontinence following pull-through for HSCR referred to the senior author and after exclusion of anatomical defects, underwent nuclear transit studies. Most (8) subsequently underwent breath hydrogen tests for sugar malabsorption and were tested for adverse reactions to food. Exclusion diets for protein allergens, lactose or fructose were then trialed. Of the 10 patients with rapid intestinal transit proven on nuclear transit study, breath hydrogen tests for fructose and/or lactose malabsorption were done in 8, and were positive in 7/8 patients. Exclusion diets contributed to either resolution or improvement in faecal incontinence in 9/10 patients. Rapid transit in the proximal, ganglionated colon may be present in children with faecal incontinence following pull-through for HSCR, possibly secondary to adverse reactions to food. This study suggests that children with post-operative soiling may benefit from a transit study and hydrogen breath tests to diagnose adverse reactions to food caused by sugar malabsorption.

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.

Small intestinal bacterial overgrowth (SIBO) is reported in 4-78% patients with irritable bowel syndrome (IBS). This wide range of percentages might be because of the different techniques and criteria used to define the condition. We studied the utility of early (breath hydrogen increase 20 ppm above basal within 90 min) and double peaks on lactulose and glucose hydrogen breath tests (LHBT and GHBT, respectively) to diagnose SIBO (gold standard: upper gut aspirate culture). We also studied the clinical parameters that are associated with SIBO among them.Overall, 80 patients with IBS (Rome 3) were evaluated for SIBO using aspirate culture, GHBT, and LHBT (with methane).A total of 15/80 (19%) patients had SIBO (≥ 10 CFU/ml) on culture compared with 0/10 historical controls; 4/15 (27%) with and none of 65 without SIBO had positive GHBT (sensitivity 27%, specificity 100%). None of 15 with and one of 65 without SIBO had double peaks on LHBT (sensitivity 0%, specificity 98%); 5/15 (33%) with and 23/65 (35%) without SIBO had an early peak on LHBT (sensitivity 33%, specificity 65%); and 2/15 (13.3%) with and 26/63 (41.3%) without SIBO had high methane on LHBT (sensitivity 13.3%, specificity 58.7%). Patients with SIBO on culture more often had diarrhea [6/15 (40%) vs. 8/65 (12.3%), P=0.011], higher weekly stool frequency [21 (3-28) vs. 14 (4-49), P=0.003], and looser forms [Bristol 5-6, 11/15 (73.3%) vs. 33/65 (50.8%), P=0.116].On the basis of culture, 19% patients with IBS had SIBO. The specificity of GHBT was 100%, but the sensitivity of this test and the diagnostic performances of LHBT and breath methane were all very poor. SIBO was more common in IBS patients with diarrhea than in patients with other bowel habits.

Diets low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPS) are used to manage symptoms in individuals with irritable bowel syndrome. Although effective at reducing symptoms, the diet can be complex and restrictive. In addition, there are still large gaps in the literature and many foods with unclear effects in the gastrointestinal (GI) tract, like fruit juice. Although many fruits are allowable on a low-FODMAP diet, consumption of all fruit juice is generally cautioned due to the large fructose load contained in juice, regardless of the glucose concentration. Very little research exists regarding the importance of limiting fructose load during a low-FODMAP diet; therefore, individuals following a low-FODMAP diet may be unnecessarily restricting their diets.To determine whether there is a difference in GI tolerance between juice from a high-FODMAP fruit (apple juice) and juice from a low-FODMAP fruit (white grape juice) in healthy human subjects. The goal is to provide insight into the role of juice in a low-FODMAP diet.A double-blind, randomized, controlled crossover study was conducted with 40 healthy adults. Fasted subjects consumed 12 oz of either apple juice or white grape juice. Breath hydrogen measures were taken at baseline, 1, 2, and 3 hours. Subjective GI tolerance surveys were completed at the same time intervals and at 12 and 24 hours. Breath hydrogen and GI symptoms were assessed with area under the curve analysis. Significance was determined with a two-sided t test with a P value0.05.Consumption of apple juice resulted in a greater mean breath hydrogen area under the curve at 23.3 ppm/hour (95% CI 13.0 to 33.6) compared with white grape juice at 5.8 ppm/hour (95% CI -4.6 to 16.1) (P0.001). No differences in reported GI symptoms were seen between treatments.Both juices were well tolerated and neither produced any severe symptoms in healthy adults. White grape juice consumption resulted in only a small rise in breath hydrogen, which may suggest excluding foods only because of the high fructose load could be unnecessarily restrictive. The results of this study suggest that the fructose-to-glucose ratio is likely more important than the total fructose load of the food when considering the acceptability of a food on a low-FODMAP diet. More research is needed in individuals with irritable bowel syndrome to determine whether white grape juice and other juices from low-FODMAP fruits could be additional beverage options for individuals following a low-FODMAP diet.

Massive bubble formation after diving can lead to decompression sickness (DCS) that can result in neurological disorders. In experimental dives using hydrogen as the diluent gas, decreasing the body's H2burden by inoculating hydrogen-metabolizing microbes into the gut reduces the risk of DCS. In contrast, we have shown that gut bacterial fermentation in rats on a standard diet promotes DCS through endogenous hydrogen production. Therefore, we set out to test these experimental results in humans. Thirty-nine divers admitted into our hyperbaric center with neurological DCS (Affected Divers) were compared with 39 healthy divers (Unaffected Divers). Their last meal time and composition were recorded. Gut fermentation rate was estimated by measuring breath hydrogen 1-4 h after the dive. Breath hydrogen concentrations were significantly higher in Affected Divers (15 ppm [6–23] vs. 7 ppm [3–12]; P = 0.0078). With the use of a threshold value of 16.5 ppm, specificity was 87% [95% confidence interval (CI) 73–95] for association with neurological DCS onset. We observed a strong association between hydrogen values above this threshold and an accident occurrence (odds ratio = 5.3, 95% CI 1.8–15.7, P = 0.0025). However, high fermentation potential foodstuffs consumption was not different between Affected and Unaffected Divers. Gut fermentation rate at dive time seemed to be higher in Affected Divers. Hydrogen generated by fermentation diffuses throughout the body and could increase DCS risk. Prevention could be helped by excluding divers who are showing a high fermentation rate, by eliminating gas produced in gut, or even by modifying intestinal microbiota to reduce fermentation rate during a dive.

Background: There is growing evidence that gut flora plays a role in the development of Irri- table Bowel Syndrome (IBS). Abdominal bloating is a common symptom in these patients and the severity of this symptom could be related to the variations in their fermentative profiles, obtained by measuring the levels of breath hydrogen excretion after lactulose ingestion. Aims: Our objective was to determine the difference in abdominal bloating severity between IBS patients with high vs low levels of breath hydrogen excretion after lactulose administration. Methods: Lactulose breath tests were carried out on IBS patients in our institution between July 2009 and August 2010. Patients were requested to fill out a validated questionnaire to assess the severity of their symptoms. Abdominal bloating severity score was compared among patients with high and low breath hydrogen levels. Results: A total of 234 patients were enrolled. There was a statistically significant difference in the abdominal bloating severity score between groups: 7.0 (5.7-8.0) vs 6.5 (5.0-7.5), p=0.001. The comparison among IBS patients with constipation (IBS-C) in both groups also showed a statistically significant difference: 7.5 (6.0-8.5) vs 5.8 (3.5-7.2), p=0.0051. Conclusions: Those patients with a low level of breath hydrogen excretion after lactulose inges- tion presented with significantly greater abdominal bloating than those with a high level of breath hydrogen excretion. © 2011 Asociacion Mexicana de Gastroenterologia. Published by Masson Doyma Mexico S.A. All rights reserved.

Background Currently, there is no ‘gold standard’ for detecting patients with sensitivity to lactose. Biochemical investigation by a breath hydrogen test alone detects 13910 and G/A22018 polymorphisms, strongly associated with lactose sensitivity, has not been established. Methods Two hundred and ten patients with unexplained gut and systemic symptoms and controls were challenged with 50 g lactose. Breath hydrogen and methane were measured and symptoms recorded. All were genotyped for two polymorphisms, C/T13910 and G/A22018. Results CC13910/GG22018 in 14.5%, CT13910/GA22018 in 39% and TT13910/AA22018 in 46.5%. One hundred percent of CC13910/GG22018 were lactose sensitive having a breath hydrogen >20 ppm within 6 h and symptoms. But the breath hydrogen test lacked sensitivity and specificity in the other groups. There was elevated breath hydrogen in 21% of CT13910/GA22018 and 15% of TT13910/AA22018 by 6 h, whereas 17 and 30.9% had elevated breath methane alone. Breath methane and breath hydrogen with clinical symptoms improved sensitivity and specificity, increasing detection of lactose sensitivity in genotypes CT/GA and TT/AA from 75%. Conclusions The data presented define the current best practice for the clinical identification of lactose sensitivity. Patients were first genotyped. Those identified as CC with symptoms should immediately undertake a 12-week lactose-free diet. Those identified as CT or TT should undertake a breath hydrogen and methane test. Those positive for hydrogen or methane along with symptoms or with symptoms only, should also undertake a lactose-free diet. Those with high hydrogen without symptoms should be investigated for causes other than lactose sensitivity.

Recently, there has been considerable interest in the satiety inducing properties of inulin type fructans (ITF) as a tool for weight management. As a staple food, breads provide an excellent vehicle for ITF supplementation however the integrity of the ITF chains and properties upon bread making need to be assessed. Breads enriched with 12% fructooligosaccharides (FOS) and 12% inulin were baked and the degree of polymerisation of fructans extracted from the breads were compared to those of pure compounds. An acute feeding study with a single blind cross-over design was conducted with 11 participants to investigate the effect of ITF enriched breads on breath hydrogen, self-reported satiety levels, active ghrelin, total PYY and energy intake. Size exclusion chromatography indicated that little or no depolymerisation of inulin occurred during bread making, however, there was evidence of modest FOS depolymerisation. Additionally, ITF enriched breads resulted in increased concentrations of exhaled hydrogen although statistical significance was reached only for the inulin enriched bread (p = 0.001). There were no significant differences between bread types in reported satiety (p = 0.129), plasma active ghrelin (p = 0.684), plasma PYY (p = 0.793) and energy intake (p = 0.240). These preliminary results indicate that inulin enriched bread may be a suitable staple food to increase ITF intake. Longer intervention trials are required to assess the impact of inulin enriched breads on energy intake and body weight.

Backgrounds The bacterial overgrowth might be associated with chronic pancreatitis. This study was to evaluate the prevalence and characteristics of small intestinal bacterial overgrowth (SIBO) in patients with chronic pancreatitis. Methods 36 patients with chronic pancreatitis and 49 healthy controls undergoing the hydrogen (H 2 )–methane (CH 4 ) lactulose breath test (LBT) were reviewed. The LBT positivity (+) indicating the presence of SIBO, gas types, bowel symptom questionnaire, laboratory and radiologic results were surveyed. The LBT+ was (1) an increase in the breath H 2 (≥20 ppm) or CH 4 (≥10 ppm) over the baseline or (2) a baseline H 2 (≥20 ppm) or CH 4 (≥10 ppm) within 90 min after lactulose load. Results LBT+ was significantly higher in the patients (17/36) than in controls (13/49) (47.2% vs. 26.5%, P 2 levels between 0 and 105 min were significantly higher in patients than in controls. Among LBT+ patients, 11 (64.7%), 1 (5.9%), 5 (29.4%) were in the LBT (H 2 )+, (CH 4 )+, (mixed)+ groups, respectively. The LBT+ group had significantly higher scores of flatus than those of the LBT− group. Considering the subtypes of LBT, the LBT (mixed)+ group had higher symptom scores of significance or tendency in hard stool, strain, urgency, and flatus than LBT− group The laboratory and radiologic features were not significantly different between LBT+ and LBT− groups. Conclusions SIBO is common in patients in chronic pancreatitis. Especially, excretions of mixed H 2 and CH 4 appear to be related with deterioration of intestinal symptoms.

The aim of this study was to determine a relationship between pretest intake of lactose and outcome of lactose breath hydrogen test. Patients presented at a testing laboratory participated in the study. A 3-hour breath hydrogen, 50-g lactose challenge was carried out. Results were tabulated and patients completed a 3-day recall diet questionnaire. Daily lactose intake was independently calculated and was associated with breath hydrogen and total symptom score. Statistical analysis used Spearman's correlation, Mann-Whitney U-test and chi2 or Fisher exact test. Of 118 patients, 50% were lactose maldigesters. In these patients, measured breath hydrogen and symptom scores were significantly higher in the lowest intake group (5 g/d) than in the highest intake group (20 g/d) (P.05). In the presumed lactose digesters, 59% experienced some symptoms during testing for unclear reasons. Pretest dietary intake of lactose inversely affects results of breath hydrogen.

We evaluated the safety and change in fermentability from repeated ingestion of difructose anhydride III (DFAIII) in humans. A randomized controlled single-blind crossover study with thirteen subjects was conducted. Each subject ingested 5 g of DFAIII or palatinose daily for 12 days, before and after which the subject was loaded with 10 g of DFAIII and had breath hydrogen measured from 0 to 9 h (DL test) to evaluate the fermentability of DFAIII. The defecation frequency and abdominal symptom score were the same between each ingestion period. Moreover, DFAIII ingestion had no influence on blood test results. Only the breath hydrogen excretion in post-DFAIII ingestion was slightly higher at h 8 than the pre-ingestion. Consequently, repeated ingestion of DFAIII for 12 days was as safe as palatinose ingestion, especially with respect to abdominal symptoms and blood test results, and its high resistance to enterobacterial fermentation in humans was not impaired.

Objectives: To clarify the difference of digestibility in the small intestine among fructo-oligosaccharide (FOS), galactosyl-sucrose (GS), and isomalto-oligosaccharide (IMO) using breath hydrogen test. Design: The first step: screening test of breath hydrogen excretion and FOS tolerance test to select the subjects. The second step: breath hydrogen test of three kinds of oligosaccharides, carried out using precautionary regulations. The ingestion order was 10 g of FOS, GS, and IMO, with increases, at 1-week interval, up to 20 g, respectively. Breath gas was collected before, at 20 min intervals from 40 to 120 min after, and at 30 min intervals from 120 min to 7 h after ingestion of test substance. Setting: Laboratory of Public Health Nutrition, Department of Nutrition and Health Sciences, Siebold University of Nagasaki, Nagasaki, Japan. Subjects: A total of nine males (average: age 25.7±3.5 y, weight 61.9±8.8 kg, height 170.0±6.0 cm) and 29 females (average: 23.1±7.2 y, 52.9±5.3 kg, 157.5±5.1 cm) from the University of Tokyo and Siebold University of Nagasaki. Main outcome measures: Breath hydrogen excretion from end-expiratory gas. Result: Breath hydrogen of FOS was more remarkably excreted than that of GS; that of IMO was slight; and that of AUC (10 g) was significantly different. FOS was 9768±3253 ppm, GS was 3662±2632 ppm, and IMO was 831±1154 ppm. A dose dependence was observed at doses between 10 and 20 g of FOS and GS, and the initial time of 20 g was earlier than that of 10 g. Conclusions: FOS was not hydrolyzed, GS was slightly hydrolyzed, and IMO was readily hydrolyzed by small intestinal enzymes. H2 gas reflected fermentability in the large intestine. Sponsorship: Siebold University of Nagasaki.

Background Breath hydrogen levels after ingestion of polyethylene glycol were evaluated as a method of predicting the quality of colonic preparation. Methods : One hundred patients undergoing nonemergency colonoscopy were recruited for this study. After fasting overnight, they were instructed to ingest a polyethylene, glycol solution containing 12 g lactulose at a rate of 50 mL every 5 minutes for 2 hours. During ingestion of the polyethylene glycol solution, breath samples were taken at 15-minute intervals for 240 minutes and breath hydrogen concentration was measured. Results : The preparation for colonoscopy was judged to be poor in 18% and adequate in 82%. The breath hydrogen levels over 90 minutes were significantly higher in the poor group than in the adequate group. In all patients with a breath hydrogen level less than 10 parts per million at 240 minutes, the preparation was adequate. Conversely, all patients with a poor preparation had a breath hydrogen level of more than 10 ppm at 240 minutes. Conclusions : The hydrogen breath test effectively predicts adequacy of colonic preparation.

Objective. Abdominal symptoms are common after bariatric surgery, and these individuals commonly have upper gut bacterial overgrowth, a known cause of malabsorption. Breath hydrogen determination after oral glucose is a safe and inexpensive test for malabsorption. This study is designed to investigate breath hydrogen levels after oral glucose in symptomatic individuals who had undergone Roux-en-Y gastric bypass surgery.Methods. This is a retrospective study of individuals (n=63; 60 females; 3 males; mean age 49 years) who had gastric bypass surgery and then glucose breath testing to evaluate abdominal symptoms.Results. Among 63 postoperative individuals, 51 (81%) had a late rise (≥45 minutes) in breath hydrogen or methane, supporting glucose malabsorption; 46 (90%) of these 51 subjects also had an early rise (≤30 minutes) in breath hydrogen or methane supporting upper gut bacterial overgrowth. Glucose malabsorption was more frequent in subjects with upper gut bacterial overgrowth compared to subjects with no evidence for bacterial overgrowth (P<0.001).Conclusion. These data support the presence of intestinal glucose malabsorption associated with upper gut bacterial overgrowth in individuals with abdominal symptoms after gastric bypass surgery. Breath hydrogen testing after oral glucose should be considered to evaluate potential malabsorption in symptomatic, postoperative individuals.

Breath hydrogen (H(2)) concentration, an indicator of intestinal microbial abundance, was determined in cats given purified and commercial canned and dry-type diets. Before measurements, the cats were fed diets for more than 2 wk and habituated to a daily feeding interval of 4 hr. Breath H(2) concentrations were determined before a meal (approximately 25% daily MER) and then every 20 min for 8 hr or hourly for 10 hr. A clear rise above baseline breath H(2) concentrations, 1-2 ppm, was not observed in 6 males given a casein-based purified diet. A mean (+/- SEM) peak breath H(2) concentration of 22 +/- 4 ppm was observed in 6 other males, 6.3 hr after ingestion of a canned diet with protein, fat, and carbohydrate proportions similar to those of the purified diet. Area-under-the-curve (AUC) breath H(2) responses to the canned diet were substantially greater (p0.05) than responses observed in 5 males given a dry-type diet, but similar to responses observed in 12 males given an uncooked form of the canned diet. Gamma irradiation to inactivate microbes in the uncooked diet did not affect the breath H(2) response. Breath H(2) responses to 2 other canned and 2 other dry-type diets were evaluated in 8 adult females using a 4 x 4 Latin-square design. Peak and AUC responses to the canned diets were similar but approximately 2 times greater (p0.05) than responses to the dry diets. Relative to dry-type diets, canned diets induce a substantially greater breath H(2) production, and therefore appear to support a greater intestinal microbial population.

Prebiotics play a role in the development of intestinal flora. When exposed to unabsorbed food, such as prebiotic carbohydrates, intestinal bacteria produce hydrogen. Increases in hydrogen may signify a slower rate of fermentation or digestion. In this blinded, crossover study, infants (n = 13) consumed formula containing either 4 g/L galactooligosaccharide (GOS) or 4 g/L polydextrose (PDX) + GOS, and breath hydrogen was measured. Breath hydrogen was higher in the PDX/GOS group versus GOS alone (mean ± standard error, 25.35 ± 2.87 ppm vs 13.69 ± 2.87 ppm, P = 0.0001). These results indicate that the formula with PDX/GOS may have undergone slower digestion.

A breath hydrogen test has been used widely as a noninvasive and simple method of detecting carbohydrate malabsorption as well as estimation of the small intestinal and orocecal transit time. By means of this method, we have examined the change in breath hydrogen concentration of young female students in their everyday life in order to reveal the breath hydrogen excretion profile under normal circumstances. In this survey, we have asked them to collect their own breath samples every one-hour as regularly as possible during one day from awakening until bedtime. We also asked them to complete the questionnaire concerning their dietary habit, dietary record and physical activities. Among the 43 subjects who gave the breath hydrogen records, 37 subjects excreted detectable hydrogen into their alveolar air. By comparing the changes in breath hydrogen concentration during the time of day, breath hydrogen excretions could be classified into two distinct patterns; more than half of the total hydrogen excretion occurred in the first half of the waking hours (designated as "pattern A", 18 cases) and in the latter half (designated as "pattern B", 19 cases). Taking into consideration the subjects' records of diets and physical activities, the early-pronounced breath hydrogen excretion observed among 18 "pattern A" students was probably resulted from the malabsorption of the dietary carbohydrate in the breakfast meals.

The aim of this study was to establish the normal patterns of breath hydrogen excretion in adult ponies following either voluntary consumption or administration per stomach tube of a test meal/carbohydrate substrate. After an overnight fast, the ponies (n = 7) received either no test meal (ie fasted), glucose, xylose, lactose, lactulose, wheat flour or oats. Exhaled breath samples were collected in duplicate at 0 minutes and at 30-minute intervals thereafter for eight hours. Analysis of duplicate breath hydrogen measurements (n = 714) indicated that the breath hydrogen collection/storage method was reliable. Fasting resulted in negligible levels of breath hydrogen excretion. Increases in breath hydrogen concentration greater than 10 ppm, sustained for at least 30 minutes, were regarded as being biologically significantly different than fasting data and were observed for all ponies following the ingestion of oats or the administration of wheat flour, for three ponies following the administration of glucose and xylose and for two ponies following the administration of lactulose and lactose. The pattern of breath hydrogen excretion was subject to variation between animals following the ingestion of identical test meals. This study provides evidence of incomplete glucose absorption in healthy ponies and indicates that ingestion of non-absorbable carbohydrates do not always result in hydrogen excretion.

To investigate whether resistant starch (RS) affects putative risk factors for colon cancer, 24 healthy men consumed a daily RS supplement for 4 wk in addition to their habitual diet in a single-blind, randomized, balanced multiple crossover trial. During the first week, all subjects consumed the control supplement containing glucose. Subsequently, each subject consumed, in random order, a supplement with RS2 (uncooked high-amylose cornstarch), RS3 (extruded and retrograded high-amylose cornstarch), and glucose, each for 1 wk. The RS2 and RS3 supplements provided 32 g RS/d. Lithium was added to the supplements to measure compliance. Feces, 24-h urine, and breath samples, as well as a 24-h food-consumption recall were obtained weekly from each subject. Compliance as measured by urinary lithium recovery was satisfactory. The mean composition of the background diet did not differ between the various supplementation periods. Breath-hydrogen excretion, stool weight, and fecal starch excretion were significantly higher during RS than during glucose supplementation, but did not differ during RS2 and RS3 supplementation. There were no significant differences in fecal dry weight, pH, or short-chain fatty acid concentrations, nor in the pH, bile acid concentrations, cytotoxicity, or osmolality of fecal water. It is concluded that in healthy men, supplementing the habitual diet for 1 wk with 32 g RS2 or RS3/d compared with glucose had no effect on putative risk factors for colon cancer, except for increasing stool weight and colonic fermentative activity. There were no significant differences between the effects of RS2 and RS3 on the indexes studied.

Patients with large bowel disease may undergo ileal pouch-anal anastomosis, in which the colon is removed and part of the distal ileum is used to construct a pelvic reservoir. Competence of the ileal pouch to ferment carbohydrates is associated with the absence of pouchitis. However, the extent to which bacterial fermentation takes place and whether it is affected by diet are unclear. We investigated fermentation of two nondigestible carbohydrates, fructooligosaccharides and resistant starch, in 15 healthy patients with an ileal pouch by using a placebo-controlled crossover design (with glucose as the placebo). Apparent fermentability of fructooligosaccharides was 83%; that of resistant starch was 46%. Resistant starch increased fecal excretion of butyrate by 69% whereas fructooligosaccharides reduced excretion of amino acid-derived isobutyrate by 94% and of isovalerate by 77%. Fructooligosaccharides also significantly increased fecal weight (651 compared with 541 g/d) and breath-hydrogen excretion (286 compared with 85 ppm x h). Bacterial fermentation of nondigestible carbohydrates in pouches takes place to an appreciable extent and in a substrate-specific manner. The relation between such fermentation and inflammation of the pouch (pouchitis) deserves study.

In this article, technical developments in breath analysis and its applications in the field of clinical diagnosis and the monitoring of various symptoms, particularly molecular hydrogen in breath, are introduced. First, a brief overview of the current uses of the hydrogen breath test is provided. The principles of the test and how hydrogen can be used as a biomarker for various symptoms, and monitoring microbial metabolism, are introduced. Ten case-study applications of breath hydrogen measurements for which hydrogen exhibits beneficial effects for diagnosis, including the contexts of oxidative stress, gastrointestinal disease, and metabolic disorders, are discussed. The technologies and problems involved in breath hydrogen testing, sampling, pretreatment, and detection in exhaled breath are discussed, and research including current analytical systems and new sensors is focused on in the context of hydrogen detection.

Soft drinks containing dietary fiber are popular in Japan. There seem to be two types, one containing polydextrose and the other, oligosaccharide. These beverages are claimed to be useful for constipation or obesity, but data are scanty. We examined four such fiber-containing beverages [Fibe-mini Otsuka Pharmaceuticals (Tokyo, Japan), Seni and Oligo Takeda Food Engineering (Osaka, Japan), Oligo CC (Calpis Food Engineering, Tokyo, Japan), and Sapitus 5289 Nakakita Pharmaceuticals (Nagoga, Japan)] for large intestine fermentability by measuring breath hydrogen (H2) and methane (CH4). Five healthy subjects (two men, three women, 22-48 years old) participated in the study. Breath H2 and CH4 were measured with a MicroLyzer (Quintron Instruments, Milwaukee, Wis.). Breath H2 increased within 2h of beverage consumption, but CH4 excretion was observed in only two subjects. Orocecal transit time was constant for all beverages. Total H2 plus CH4 excretion (AUC; area under the curve) after lactulose was 1294 +/- 250 ppm x min/g fiber. AUC for Oligo CC was significantly greater than that for Fibe-mini or Sapitus 5289 (P0.05). The AUCs of Fibe-mini, Seni and Oligo, Oligo CC, and Sapitus 5289 were 41%, 129%, 174%, and 40%, respectively, that of lactulose. It is concluded that commercial fiber-containing drinks produce H2, and CH4 in some people. Oligosaccharide produces more H2 and CH4 than polydextrose.

As consumption of dietary fructose and sorbitol increases, the association between consumption of these sugars and gastrointestinal symptoms has been recognized. As a result, studies of fructose and sorbitol absorption and malabsorption have emerged with investigations relying largely on the use of breath hydrogen (H2) measurements. Since these sugars are prevalent in fruit juices, a major dietary staple in the first 5 years of life, an understanding of fructose and sorbitol absorption is particularly important to pediatric health care providers. This review examines fructose and sorbitol absorption in humans, reviewing as well the breath H2 method upon which studies of fructose and sorbitol absorption largely depend.

Inhaling or ingesting hydrogen (H2) gas improves oxidative stress-induced damage in animal models and humans. We previously reported that H2 was consumed throughout the human body after the ingestion of H2-rich water and that the H2 consumption rate (\( {\text{V}}_{{\text{H}}_{2}}\)) was 1.0 μmol/min/m2 body surface area. To confirm this result, we evaluated \( {\text{V}}_{{\text{H}}_{2}}\)during the inhalation of low levels of H2 gas. After measuring the baseline levels of exhaled H2 during room air breathing via a one-way valve and a mouthpiece, the subject breathed low levels (160 ppm) of H2 gas mixed with purified artificial air. The H2 levels of their inspired and expired breath were measured by gas chromatography using a semiconductor sensor. \( {\text{V}}_{{\text{H}}_{2}}\) was calculated using a ventilation equation derived from the inspired and expired concentrations of O2/CO2/H2, and the expired minute ventilation volume, which was measured with a respiromonitor. As a result, \( {\text{V}}_{{\text{H}}_{2}}\) was found to be approximately 0.7 μmol/min/m2BSA, which was compatible with the findings we obtained using H2-rich water. \( {\text{V}}_{{\text{H}}_{2}}\) varied markedly when pretreatment fasting to reduce colonic fermentation was not employed, i.e., when the subject’s baseline breath hydrogen level was 10 ppm or greater. Our H2 inhalation method might be useful for the noninvasive monitoring of hydroxyl radical production in the human body.

The colonic fermentation of two diets differ- ing in amounts of resistant starch (RS) was studied. High- and low-RS diets were fed to eight healthy subjects in three meals for 1 d. Breath hydrogen and two blood samples were collected oven a 28-h period. The high-RS diet provided 59.1 ± 4.7 g (1 ± SE) RS and the low-RS diet provided 5.2 ± 0.4 g RS. Breath hydrogen and the average total serum acetate were significantly higher during the high-RS diet than during the low-RS diet: 34.1 ± 4.7 and 23.9 ± 3.9 ppm (P < 0.001) and 169.1 ± 12.8 and 1 18 ± 6.6 pmol/L (P < 0.01), respectively. Butynate and propionate were also detected in serum samples. Although not statistically significant, there was a trend (P = 0.087) for butynate to increase with the high-RS diet. Subjects reported greater gastrointestinal symptoms during the high-RS diet. These results suggest that RS may have effects comparable with those of some fermentable dietary fibers. Am J Clin Nutr 1994;61 :792-9.

The effect of eating chocolate containing sugar alcohols as sweetening agents on colonic fermentation has been investigated by monitoring breath H2levels. Levels were compared with those occurring after the consumption of normal, sugar-containing chocolate. Ten healthy volunteers aged 19 to 21 years ingested equal amounts of either sorbitol, isomalt or sucrose incorporated into standard chocolate bars. Breath H2levels after consumption of chocolate containing either sorbitol or isomalt were significantly higher than those after consumption of chocolate containing sucrose (P< 0.001). After consumption of chocolate containing sorbitol, double the mean estimated volume of breath H2was produced over 6 h compared with that produced after eating chocolate containing isomalt. Taken together with results relating to the incidence of intolerance symptoms, these findings demonstrate that sorbitol is associated with greater colonic fermentation compared with isomalt.

The purpose of this study was to determine the concentration of carbon monoxide (CO) in blood (COHb) and breath to demonstrate that breath hydrogen (H2) can be a significant interferant. For this purpose, we measured blood COHb with CO-oximetry and breath CO with an electrochemical analyzer. In addition, the samples were analyzed by gas chromatography (GC). The concentration of CO in breath, collected with a Priestley tube after a 20 s breath hold, from healthy, nonsmoking adult males (n = 20) and females (n = 10) had a mean ± SD (range) of 2.6 ± 0.4 ppm (2.0–3.9), respectively, when measured by GC. However, these same samples when measured with an electrochemical (EC) analyzer showed elevated CO values of 4.7 ± 2.9 ppm (2.6–17.6). The concentration of H2, a prominent trace gas in breath known to interfere with EC analyzers, correlated strongly with the observed EC analyzer response [EC (ppm CO) = 0.336 H2 (ppm) + 1.93, r2 = 0.98]. The EC analyzer was linear for H2 concentrations up to 40 ppm, with a sensitivity of 0.035 V ppm−1. The analyzer sensitivity to CO was 0.10 V ppm −1. Blood from this population showed COHb concentrations of 0.56 ± 0.11% (0.40–0.97), as measured by GC, but elevated values were found when measured by CO-oximeter (Ciba Corning Diagnostics Corp., Models 2500 and 270), 1.3 ± 0.2% (1.1–1.6) and 1.0 ± 0.3% (0.1–1.6), respectively. When breath CO was compared to blood COHb, only measurements by GC significantly correlated [COHb% = 0.241 CO(ppm) — 0.076, r2 = 0.78]. We conclude that, relative to quantitative analysis by GC, (1) EC analyzers are susceptible to H2 interference that cause falsely elevated CO measurements, and (2) CO-oximeters overestimate COHb concentrations in the range typical for healthy nonsmokers.

Recent studies have shown reduced breath hydrogen (H2) excretion in methane (CH4)-producing healthy individuals following ingestion of lactulose. This questions the reliability of the breath hydrogen test (BHT) in CH4 excretors, but the relationship between CH4 and H2 excretion in other clinical applications of the BHT is not known. We reviewed BHT results in two groups of subjects: (1) 385 children tested for lactose malabsorption in a hospital setting, and (2) 109 lactose-malabsorbing patients tested with a home kit. The percentage of lactose malabsorbers in group 1 (51%) was the same regardless of CH4-producing status (P = 0.97). The BHT data from group 2 showed a positive correlation (r = 0.6, P0.000001) between the magnitude of the rise in CH4 and H2 concentrations, and the H2 excretion curves were significantly higher in the CH4-producing individuals. We conclude that attention to CH4-producing status is not necessary in the interpretation of the lactose BHT.

Previous studies have shown that there is minimal fecal excretion of carbohydrate energy in premature infants with high breath H2 concentrations, implying that the colon plays an important role in salvaging lactose energy. The present study extends this work by using a stable isotope method for serial assessment of lactose carbon excretion. Thus, in nine premature infants (30-32 weeks of gestation and 11-36 days of age), we conducted 23 longitudinal studies of breath hydrogen concentration and the cumulative fecal excretion of 13C derived from a single dose of [D-1-13C]lactose. The ranges of values (mean +/- SD) for breath hydrogen concentration and lactose absorption were respectively 4-440 ppm/5% CO2 (92 +/- 100) and 82-100% tracer dose (98.4 +/- 3.9). In 21 studies, lactose carbon excretion was less than 2% of the dose. There was a significant correlation between postnatal age and breath hydrogen concentration (R = 0.48; p = 0.02). These studies suggest that colonic fermentation activity is adequate for efficient colonic salvage of lactose even during the second week of life.

Breath hydrogen excretion was measured serially in breast-fed infants. There was marked variability in H2 excretion, both within and between infants. The findings indicate that unabsorbed food is not the only substrate, and that breath H2 may not be an effective method to assess carbohydrate absorption in young infants.

Breath hydrogen excretion during the neonatal period was studied on 84 occasions in 44 well premature infants of 27-37 weeks gestational age who all received lactose-containing feeds. Only one of 15 infants studied during the first 24 h excreted hydrogen. Thereafter, the proportion of infants excreting hydrogen increased daily. From day 5 onwards all the infants studied were found to be excreting hydrogen. The concentration and the volume of hydrogen exhaled by infants ranged from 10-230 parts/10(6) and 2.6-107 microL/min, respectively. Breath hydrogen excretion was variable and showed no relationship to birthweight, gestation period, volume of feed or the time of last feed through there was an increase with the age of the infant. Breath hydrogen excretion appears to be a normal phenomenon in premature infants and is probably related to gut colonization with lactose fermenting organisms.

Objective To compare how and to what extent ingestion of hydrogen water and milk increase breath hydrogen in adults. Methods Five subjects without specific diseases, ingested distilled or hydrogen water and milk as a reference material that could increase breath hydrogen. Their end-alveolar breath hydrogen was measured. Results Ingestion of hydrogen water rapidly increased breath hydrogen to the maximal level of approximately 40 ppm 10–15 min after ingestion and thereafter rapidly decreased to the baseline level, whereas ingestion of the same amount of distilled water did not change breath hydrogen (p < 0.001). Ingestion of hydrogen water increased both hydrogen peaks and the area under the curve (AUC) of breath hydrogen in a dose-dependent manner. Ingestion of milk showed a delayed and sustained increase of breath hydrogen in subjects with milk intolerance for up to 540 min. Ingestion of hydrogen water produced breath hydrogen at AUC levels of 2 to 9 ppm hour, whereas milk increased breath hydrogen to AUC levels of 164 ppm hour for 540 min after drinking. Conclusion Hydrogen water caused a rapid increase in breath hydrogen in a dose-dependent manner; however, the rise in breath hydrogen was not sustained compared with milk.

To estimate colonic carbohydrate fermentation following a potato meal, 13 healthy volunteers consumed 375 g potatoes containing 60 g starch on three different occasions in random order: (A) potatoes boiled and consumed fresh at 60 degrees C; (B) potatoes boiled, frozen, thawed and consumed at 20 degrees C; and (C) potatoes boiled, frozen, thawed, reheated to 90 degrees C, and consumed at 60 degrees C. End-expiratory breath hydrogen (H2) was measured every 15 min for 10-14 hr with a selective electrochemical cell. The extent of colonic carbohydrate fermentation (AUC = area under the breath H2 concentration vs time curve) in experiment B was significantly higher (+186%, P less than 0.002) than in experiment A. The breath hydrogen AUC in experiment C was higher than in experiment A (+48%, P less than 0.04) but lower than in experiment B (-94%, P less than 0.003). It is suggested that structural alterations of the starch molecule occur during freezing, thawing, and reheating and alter the availability of carbohydrates for fermentation by colonic anaerobes.