Helicobacter pylori is associated with alterations in intestinal gas profile among patients with nonulcer dyspepsia

The pathogenesis of nonulcer dyspepsia (NUD) is unknown. Gas and postprandial bloating are frequent symptoms. The role ofHelicobacter pylori (HP) in the pathogenesis of NUD is controversial. We studied the intestinal gas profile of NUD patients (N=34) at baseline and after lactulose administration. The prevalence of hydrogen and methane producers was similar among HP+ and HP– patients. Breath H₂ concentrations in response to lactulose showed significantly greater rise among HP+ subjects (P<0.0001). HP positivity was associated with higher total breath excretion for H₂ and methane combined (2984±1038 vs 1776±521 ppm/hr) compared to HP– subjects (P<0.05). There was no correlation between peak H₂ and methane levels. The role of alterations in intestinal gas in producing symptoms in HP+ patients with NUD needs further investigation.     

Comparison of Inulin and Lactulose as Reference Standards in the Breath Hydrogen Test Assessment of Carbohydrate Malabsorption in Patients with Chronic Pancreatic Exocrine Insufficiency

Although often used as a reference standard in the breath hydrogen test (BHT), lactulose fermentation produces more hydrogen, compared to starch, and may therefore not be ideal. This study compares inulin with lactulose as reference standard in the study of carbohydrate malabsorption. Seventeen patients with malabsorption due to chronic pancreatitis and 15 normal controls were studied. Following overnight fasts, BHTs were performed after ingesting 10 g lactulose, 10 g inulin, and 200 g (16 g highly resistant starch) maize meal. Lactulose fermentation produced significantly more hydrogen than inulin in patients with malabsorption (97± 20 vs 45± 22 ppm ⋅ hr; P < 0.05) and controls (43 ± 18 vs 21 ± 10 ppm ⋅ hr; P < 0.05). Patients produced more hydrogen than controls with both standards (lactulose, 97 ± 20 vs 43 ± 18 ppm ⋅ hr, P < 0.05; inulin 45 ± 22 vs 21 ± 10 ppm ⋅ hrs; P < 0.05), suggesting adaptation of the colonic flora. Calculated CHO malabsorption was 2.5 ± 0.8 vs 5.2 ± 3.8 g with lactulose and 5.2 ± 3.1 vs 11.2 ± 9.6 g with inulin as standards in controls and patients, respectively (P < 0.05). Lactulose produces more breath hydrogen than inulin. Calculation of CHO malabsorption using these standards is therefore not comparable.This work was supported by a grant from the South African Medical Research Council.     

Efficacy of lactulose plus <Superscript>13</Superscript>C-acetate breath test in the diagnosis of gastrointestinal motility disorders

Background: Background: We designed a new method of measuring gastric emptying and orocecal transit time (OCTT) at the same time to assess the influence of gastric emptying upon OCTT. Methods: Twenty-five dyspeptic patients (6 men, 19 women) with a mean age of 64.8 years (range, 25–80 years) were studied. The patients received a liquid test meal, containing 100 mg of ¹³C-acetate and 12 g of lactulose, while they were in the sitting position after an overnight fast. Breath samples were collected at 10-min intervals of 120 min and both ¹³CO₂ and hydrogen (H₂) levels were measured. Subsequently, H₂ concentrations were measured at 30-min intervals, for a total of 240 min. Results: The results of gastric emptying were expressed as the time of peak ¹³CO₂ excretion. OCTT was defined as the period between the ingestion of lactulose and a H₂ peak rise of 5 ppm above the baseline value. The onset of H₂ enrichment in the breath began at 90–110 min, whereas ¹³CO₂ levels increased from the beginning, with peak enrichment values being reached after 60–80 min. OCTT was related to ¹³CO₂ peak time. In 5 of the 25 patients, H₂ breath enrichment in the 10-min sample was more than 5 ppm over the baseline value. All these 5 patients had double or triple peaks in serial breath H₂ concentrations. Conclusions: The combination of the lactulose hydrogen breath test (LHBT) with the ¹³C-acetate breath test, which requires only breath samples, provides us with much information on the gastrointestinal tract; gastric emptying, OCTT, bacterial overgrowth in the small intestine, colonic fermentation, and oropharyngeal flora. The ¹³C-acetate breath test can be useful as an adjuvant test when LHBT is performed for measuring OCTT. Received: March 5, 2001 / Accepted: October 5, 2001     

Relationship between methane production and breath hydrogen excretion in lactose-malabsorbing individuals

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, P<0.000001) 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.     

Impact of age,sex, race,and functional complaints on hydrogen (H2) production

In order to evaluate factors that may influence H₂ generation, the effects of age, sex, race, and functional complaints on breath H₂ were studied in 62 subjects. These included 34 young hospital employees, 17 healthy ambulatory elderly subjects, and 11 patients with functional bowel disease. The ability to produce H₂ was defined by an increase in breath H₂ to greater than 20 parts per million within 4 hr of ingesting 10 g of the nonabsorbable sugar lactulose. Overall, 21% of subjects were nonproducers, and the incidence of nonproduction did not vary among the groups. The elderly subjects had significantly greater breath H₂ concentrations than the younger subjects at 150 minutes (P<0.05). Sex, race, and functional complaints did not influence H₂ production. These findings indicate that patient's age and potential inability to make H₂ need to be considered in the routine interpretation of H₂ breath tests.     

Clinical applicability of shortenedd-Xylose breath test for diagnosis of intestinal malabsorption

Urinary and/or plasmaticd-xylose tests are broadly used in clinical practice for the diagnosis of intestinal malabsorption. A 5-hr hydrogen breath test (H₂ BT) has also proven useful. Our goal was to determine whether a shorter, hence more efficient, 3-hr test would perform as well as the 5-hr test. We studied 33 patients with proven malabsorption, 44 patients with irritable bowel syndrome (IBS), and 27 healthy subjects. Each individual ingested 25 g ofd-xylose, and alveolar breath samples were obtained thereafter at 30 min intervals for 5 hr. Breath samples were analyzed for H₂ by gas chromatography. Individual peak delta changes and area under the curve (AUC) were calculated. Simultaneously, the 5-hr cumulative urinary excretion ofd-xylose was measured by colorimetry. Results of 5-hr tests were compared with those of the first 3 hrs. In the malabsorption group, the 5-hr test showed a markedly enhanced production of H₂ relative to healthy controls (delta: 60.7±6.4 vs 7.7±1.5 and AUC: 8465.0±985.4 vs 393.2±232.6,P<0.001 for both) and a reduced urinary excretion ofd-xylose (2.8±0.3 g/5 hr vs 6.3±0.2,P<0.001). Results in IBS patients did not differ from those in healthy controls. Three-hour analysis also reflected an enhanced production of H₂ in the malabsorption group (delta: 45.4±6.4 and AUC: 3700.0±545.6,P<0.001 vs healthy controls). Correlation between 3-hr and 5-hr tests was significant in healthy controls (r=0.9), IBS (r=0.9), and malabsorption (r=0.8). The sensitivity of the 3-hr test was lower than of the 5-hr test (0.72 vs 0.91). The loss of sensitivity of the 3-hr test was attributed to a delayed appearance of the delta peak in the malabsorption group. In conclusion, the H₂ breath test withd-xylose is a useful test for the diagnosis of the intestinal malabsorption, but requires a 5-hr monitoring period to be reliable.     

Breath hydrogen and methane excretion produced by commercial beverages containing dietary fiber

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±250ppm × min/g fiber. AUC for Oligo CC was significantly greater than that for Fibe-mini or Sapitus 5289 (P<0.05). 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.     

Application of the Glucose Hydrogen Breath Test for the Detection of Bacterial Overgrowth in Patients with Cystic Fibrosis––A Reliable Method?

Patients with cystic fibrosis (CF) have recently been deemed highly susceptible for bacterial intestinal overgrowth (BIO). We aimed to define the prevalence of BIO in children with CF by applying the H₂-glucose breath test. Forty children with CF and ten healthy children received 1 g/kg D-glucose orally. Breath samples for H₂ content (ppm) were collected for 3 h. BIO was suspected if the breath hydrogen content increased by more than 20 ppm or if baseline concentrations topped 20 ppm. In 27 of 40 CF children (68%), breath hydrogen content exceeded 20 ppm. Whereas the breath hydrogen exhalation persisted above 20 ppm in almost all these children throughout the sampling period, none of the remaining children increased above this threshold. The high rate of CF children with elevated fasting hydrogen breath concentrations indicates that this phenomenon is less a sign of BIO rather than a consequence of global malabsorption and intestinal dysmotility.     

Effect of Predominant Methanogenic Flora on Outcome of Lactose Hydrogen Breath Test in Controls and Irritable Bowel Syndrome Patients of North India

The relationship between methanogenic flora and hydrogen (H₂) production is considered to be a possible confounding factor in the interpretation of hydrogen breath tests (H₂BT). Therefore, the present study was conducted prospectively and included 154 IBS patients (fulfilling Rome II criteria) and 286 age-and-sex-matched apparently healthy controls. Each subject underwent H₂BT after overnight fasting using 25 g lactose. Methane and H₂ were measured using an SC Microlyser from Quintron, USA, at baseline and every 30 min for a total of 4 h. Subjects with fasting methane concentration <10 ppm were labeled as low methane producers (LMP) and >10 ppm as predominant methane producers (PMP). A rise >20 ppm over base line in hydrogen concentration was taken as +ve hydrogen breath test. IBS and control groups included 66.78% and 67.53% males, respectively. Mean age in the two groups were 48.52 ± 30.54 years (range 15–68 years) and 45.67 ± 30.54 years (range 15–78 years), respectively. Hydrogen breath test was +ve in 77/154 (50%) IBS patients and in 142/286 (49.65%) in controls (P > 0.05). It was also observed that the hydrogen breath test was −ve due to PMP in 5/77 (6.49%) of IBS patients and in 29/154 (20.14%) in controls. PMP affected lactose hydrogen breath tests in 6.49–20.14% subjects. This effect is more apparent in apparently healthy subjects as compared to patients with IBS.     

Fecal Hydrogen Production and Consumption Measurements (Response to Daily Lactose Ingestion by Lactose Maldigesters)

The alteration of hydrogen (H₂)metabolism, which accounts for the large decrease inbreath H₂ excretion following prolongedingestion of malabsorbed carbohydrate (lactulose,lactose in lactose maldigesters) was studied in six lactose-maldigesting adults.Metabolic inhibitors of the three mainH₂-consuming reactions (methanogenesis,sulfate reduction, and acetogenesis) were used toindependently measure H production and consumption in fecal samples obtained after10 days of either dextrose or lactose feeding. Absolutefecal H₂ production (net of production minusconsumption) after 3 hr of incubation with lactose was approximately threefold lower after lactoseadaptation (242 ± 54 l) compared to dextroseadaptation (680 ± 79 l, P = 0.006). FecalH₂ consumption was not affected by eitherfeeding period. We conclude that decreased absolute H₂ production,rather than increased H₂ consumption, isresponsible for the decrease in breath H₂observed with lactose feeding.     

Diminished efficacy of colonic adaptation to lactulose occurs in patients with inflammatory bowel disease in remission

Lactulose has been proposed to be beneficial in treating inflammatory bowel disease (IBD). The hypothesis is based on the prebiotic potential of lactulose. A practical approach to testing its usefulness is to determine colonic adaptation to tolerable doses in patients with IBD. Our objective was to determine if a 3-week course of lactulose will decrease BH₂ and symptoms in response to an acute lactulose challenge test in control subjects and IBD patients. The design was a Prospective cohort study. Subjects were given a 30-g lactulose challenge test (test 1), and then ingested 10 g of lactulose twice a day for 3 weeks before being retested (Test 2). A third test was given after a further 5-week washout period. The main outcomes were the change in 4-hr sum of BH₂ (4HrBH₂) values obtained every 30 min, peak BH₂, and 4-hr sum of symptom score (4HrSS) during the lactulose challenge test. In addition, we also report the change in self-reported symptoms and diarrhea during the 3-week administration of lactulose. In controls, 4HrBH₂ decreased from test 1 (380.5 ± 56.6 ppm) to test 2 (288.6 ± 57.4 ppm) (P < 0.05), and returned toward test 1 levels by test 3 (307.5 ± 53.1, P > 0.5). Unlike controls, the 4HrBH₂ in patients failed to achieve significance between test 1 (444.5 ± 55.8 ppm), test 2 (366.5 ± 80.7 ppm, P > 0.2) or test 3 (411.6 ± 62.5 ppm, P > 0.2). 4HrSS results in controls followed a pattern similar to 4HrBH₂, achieving significance only in test 2 (P < 0.02). Symptoms during the intertest periods decreased by the third week in controls (P < 0.05), but not in patients (P > 0.5). Symptoms were lower in patients and varied insignificantly both in challenges and intertest periods. In conclusion, although controls adapt to a 3-week period of lactulose ingestion, IBD patients fail to meet the criteria for adaptation. However, longer studies may be needed to establish whether IBD patients are slower to adapt.     

Increased Orocecal Transit Time in Patients with Nonalcoholic Fatty Liver Disease

Intestinal bacterial overgrowth (IBO) has been suggested to play a pathogenic role in patients with nonalcoholic fatty liver disease (NAFLD). Delayed intestinal transit may contribute to IBO development. Ten nondiabetic patients with NAFLD and abnormal liver enzymes were recruited. Ten healthy individuals, matched by sex, age, and body mass index, were used as controls. Orocecal transit time (OCTT) was measured by the lactulose breath test. Anti-endotoxin core antibodies (EndoCAb) were determined. The effect of oral norfloxacin (400 mg BID during 2 weeks) on liver enzymes, lactulose breath test, and EndoCAb was also studied. NAFLD patients had higher basal breathed H₂ and prolonged OCTT compared to controls (127 ± 61 vs. 57 ± 23 min, respectively; P = 0.0037). EndoCAb titers were similar in NAFLD patients and controls. Norfloxacin administration had no effect on ALT levels, lactulose breath test, or EndoCAb titers in patients with NAFLD. The present data show evidence of deranged intestinal motility in nondiabetic patients with NAFLD and support the hypothesis that NAFLD could be linked to endotoxin-induced liver damage of intestinal origin.This work was supported in part by a grant from the Centro de Investigaciones Médicas Pontificia Universidad Católica to A.S. and Fondo Nacional de Ciencia y Tecnología (FONDECYT No. 1020641) to M.A.     

Lactulose hydrogen breath test in orocecal transit assessment

Orocecal transit time can be studied easily using the hydrogen breath test with lactulose, but the method has some important limitations. The orocecal transit time of 10 patients suffering from irritable bowel syndrome was measured twice, at a one-week interval, by breath test and scintigraphy simultaneously using an aqueous solution of 20 g lactulose containing 74 MBq of [^99mTc]DTPA. Abdominal radioactivity and alveolar hydrogen values obtained every 5 min were noted and used to obtain the following: orocecal transit time by the two methods; ileocecal lactulose flow; total and per gram of lactulose hydrogen production; mean hydrogen concentration during the right colon filling; and measurement error of the breath test with respect to the scintigraphy. In the case of the breath test, the orocecal transit time intrapatient reproducibility was better (coefficient of variation =13.5%) when a hydrogen threshold increment of 5 ppm was used; the best correlation with the scintigraphic measurement was observed at this threshold (r=0.90,P<0.001). The breath test overestimated orocecal transit time with the error correlating negatively and significantly with the total hydrogen production and, particularly, the mean hydrogen concentration (r=0.79,P<0.01): for a mean hydrogen concentration of more than 15 ppm, the error was negligible, while within this value there was a noticeable overestimation. To conclude, the lactulose hydrogen breath test is capable of giving an accurate measurement of orocecal transit time if a hydrogen threshold increment of 5 ppm is chosen and if the mean hydrogen concentration in the first 30 min of the right colon filling is taken into account.     

Lactulose Feeding in Piglets (A Model for Persistent Diarrhea and Colitis Induced by Severe Sugar Malabsorption)

We sought to determine, in a piglet model,whether severe sugar malabsorption causes colonic injuryor inflammation. Twenty-four piglets were randomized toreceive either control formula (CON) or CON supplemented with lactulose (LAC) (N = 12 each group). Afterseven days, inflammation, apoptosis, and crypt cellproliferation were assessed in the proximal colon(cecum). Lactulose feeding caused persistent diarrhea. In both groups, breath H₂concentration was low, suggesting no increasedfermentation in the LAC group. Weight gain/volumeformula intake was identical in the CON and LAC groups(0.09 ± 0.13 and 0.09 ± 0.11 g/ml) respectively. Injury to thecolon did not occur, but inflammation of the colon(scale 0-5) was greater in LAC (score of 1.5 ±1.38) than in CON (0.42 ± 0.79; P < 0.05).Cell proliferation at the basal 40% of the crypt was 92% increasedin CON (labeling index 22.8 ± 9.9 vs 11.9± 2.8; P < 0.05). We conclude that persistentfeeding during severe sugar malabsorption permits weightgain but may cause colitis.     

Gut hormones and gastrointestinal motility in children with cystic fibrosis

Intestinal dysmotility may be an important factor contributing to various gastrointestinal complications associated with cystic fibrosis. Motilin, enteroglucagon, neurotensin, and peptide YY may each play a role as endocrine hormones influencing gastrointestinal motor activity. Fasting children with cystic fibrosis (N=8) and controls (N=18) received a liquid nutrient test meal (fat 4 g/100 ml, protein 4 g/100 ml, carbohydrate 20 g/100 ml, 125 kcal/100 ml; 200 ml/m²) containing lactulose (5 g/100 ml), and the plasma concentrations of these peptides were studied. Mouth-to-cecum transit time was simultaneously studied using the breath H₂ technique. Fasting levels of peptide YY and the postprandial response of all four peptides were significantly increased in those with cystic fibrosis. In repeat studies on those with cystic fibrosis after a period of altered pancreatic enzyme supplementation, no significant changes in peptide concentrations were observed. A rise in breath H₂ permitting estimation of mouth-to-cecum transit time was noted in 17 control subjects (70–220 min, median 140). In contrast, a rise occurred in only two with cystic fibrosis after low-dose enzyme (70 and 180 min), and four after high-dose enzyme replacement (120–230 min, median 155). Altered gut hormone secretion may play a role in the pathophysiology of intestinal dysmotility in patients with cystic fibrosis.     

D-Xylose hydrogen breath tests compared to absorption kinetics in human patients with and without malabsorption

Thed-xylose breath H₂ test may be useful in characterizing intestinal absorptive function. Our aim was to determine whether breath H₂ followingd-xylose administration reflects the extent to which thed-xylose is absorbed by comparing it to a kinetic model ofd-xylose absorption. Twenty-five subjects were studied. They ingested 15 gd-xylose on the first day and 25 gd-xylose on the third day. On the second day they received 10 g intravenousd-xylose along with 15 g oral lactulose. Multiple serum and urine samples were obtained ford-xylose content to calculate its rate constants and extent of absorption by multicompartmental analysis. Breath H₂ determinations were obtained every 15 min for 3 hr following the 15 gd-xylose and lactulose ingestion. Peak breath H₂ concentration correlated with extent of absorption (r=–0.787,P<0.001),K ₀, the rate constant for nonabsorptive loss (r=0.744,P<0.001), and 5-hr urine content (r=–0.705,P<0.001). Area under the breath H₂ curve also correlated with these parameters: extent of absorption (r=–0.770,P<0.001),K ₀ (r=0.662,P<0.001), 5-hr urine content (r=–0.629,P<0.012). Peakd-xylose breath H₂ to peak lactulose breath H₂ showed no correlation with extent of absorption. The extent of absorption was higher with the 15-g dose than the 25-g dose in all patients tested (P<0.01). This was the result of decreased nonabsorptive loss (lowerK ₀), as the rate constant for absorption,K _a , was not statistically different (P>0.05). Peakd-xylose breath H₂ can be used as an inverse estimate ofd-xylose absorption. Lactulose breath H₂ cannot be used as a standard for comparison ford-xylose. The three compartment kinetic model ford-xylose absorption with passive absorption of this carbohydrate is supported by similar rate constants for absorption for the twod-xylose doses used.d-xylose at 15 g may be a more appropriate dose than 25 g for H₂ breath testing as it does not lead to increased nonabsorptive losses.Supported in part by grant RR0048, National Institutes of Health, National Center for Research Resources.     

Potential usefulness of hydrogen breath test withd-xylose in clinical management of intestinal malabsorption

Hydrogen breath tests (H₂ BT) have been used extensively to investigate intestinal dissacharidase deficiencies. A potentially useful test for assessing intestinal absorptive function, the H₂ BT withd-xylose (H₂ BT-d-xylose), has received scant attention. We report here the results of our investigation of this test in 45 patients. Fifteen patients had proved malabsorption that was due to nontropical sprue in nine, and to lymphoma, Whipple's disease, or giardiasis in the remainder. Nine patients had small-bowel bacterial overgrowth secondary to either postsurgical sequelae or intestinal dysmotility. Twenty-one patients with irritable bowel syndrome and 21 healthy individuals served as control groups. All participants ingested 25 g ofd-xylose, and alveolar breath samples were obtained thereafter at 30 min intervals for 5 hr. Breath H₂ was measured by chromatography. Basal H₂ production, peak change (Δ) and area under the curve (AUC) were calculated. Simultaneously, 5-hr urinary excretion ofd-xylose was measured by colorimetry and served as the reference test. In healthy individuals,d-xylose ingestion increased H₂ production (Δ=5.8±1.4 ppm,P<0.001). Changes were similar in patients with the irritable bowel syndrome. In contrast, the increase was of a much greater magnitude in the malabsorption group (Δ=49.9±7.2 ppm,P<0.001 vs healthy controls). AUC analysis yielded comparable results. Test performance analysis showed that, in malabsorption the H₂ BT-d-xylose had a sensitivity index of 0.86, which was identical to that of the urinaryd-xylose test. Specificity was 1 and 0.95, respectively; and predictability 1 and 0.93, respectively. All patients who responded to treatment normalized their H₂ production, whereas those who did not respond maintained their high H₂ production. In the bacterial-overgrowth group, the H₂ BT-d-xylose was only positive when the urinary excretion ofd-xylose was positive (five patients), whereas that three of the remaining four patients with normal urinary excretion ofd-xylose also had a normal breath test. We conclude that the hydrogen breath test withd-xylose is a useful, valid, and practical test for the diagnosis and follow-up of malabsorption.     

Follow-up of celiac disease withd-xylose breath test

Hydrogen breath tests (H₂-BT) are commonly used to diagnose carbohydrate malabsorption. Specifically, the H₂-BT withd-xylose has been shown to be as valid as the traditional urinary test for the recognition of intestinal malabsorption. We have now investigated the H₂-BT withd-xylose in the follow-up of patients with celiac disease. Seventeen patients with celiac disease established clinically and confirmed by jejunal biopsy were studied. H₂-BT was performed before and after treatment with a gluten-free diet for at least five months. Alveolar breath samples were obtained before administering orally 25 g ofd-xylose and thereafter at 30 min intervals for 5 hr. Samples were analyzed for H₂ by chromatography. Simultaneously, the 5-hr urinary excretion ofd-xylose was determined by colorimetry. Gluten removal significantly decreased the H₂ delta change (from 56.5±5.9 ppm to 32.2±8.8,P<0.05). A similar decrease was observed in the area under the curve (P<0.05). Conversely, urinaryd-xylose excretion increased significantly (P<0.05). Eleven of the 17 celiacs clinically improved after treatment. The H₂-BT normalized in every patient who entered remission on the gluten-free diet, whereas the urinaryd-xylose excretion remained abnormal in six of them. In the six nonresponder patients the H₂-BT remained high in five, whereas urinaryd-xylose excretion paradoxically normalized in 2. We conclude that H₂-BT withd-xylose is a useful and practical test for the follow-up of celiac disease and is simpler and more reliable than the urinaryd-xylose test.     

Hydrogen Breath Test with D-Xylose for Celiac Disease Screening Is as Useful in the Elderly as in Other Age Groups

Up to one fifth of celiac disease patients are diagnosed after the age of 60. The hydrogen breath test with d-xylose as substrate (xylose-BT) has proved useful for the diagnosis of adult celiac disease. Our aim was to determine the potential influence of age-related intestinal mucosal changes on the reliability of this test. We reviewed the results of the xylose-BT in 50 patients with clinical celiac disease in whom the diagnosis was confirmed by histology. A control group of 53 patients with various diarrheal disorders and without jejunal mucosal atrophy at biopsy was similarly studied. Both celiac patients and controls were divided into adults (age 60 years) and elderly (age >60 years). Seven of the 50 celiacs and 8 of the 53 controls were in the elderly category (P = NS). In the celiac disease group, no differences were observed between the elderly and adult patient subgroups for basal H₂ excretion (22.4 ± 42 vs 9.7 ± 11 ppm), delta increase (56 ± 43 vs 53 ± 36 ppm), or area under the curve (7452 ± 5546 vs 6739 ± 5951 ppm × min). The false negative rate was similar for celiac adult (7/43) and elderly (2/7, P = ns) patients. Sensitivity of the xylose-BT was 0.83 in adults and 0.71 in the elderly, and specificity 0.51 in adults and 0.50 in the elderly. In conclusion, the results of the xylose-BT in celiac patients are not influenced by age. The xylose-BT is as valuable a tool for the screening of celiac disease in the elderly as it is in younger patients.     

Effects of age on lactose malabsorption in Oklahoma Native Americans as determined by breath H2 analysis

Breath H₂ excretion was used to determine lactose malabsorption in 30 healthy females and 30 healthy males between the ages of 3 and 64 yr who were at least 7/8 Native American. The test meal consisted of 5 ml reconstituted nonfat dry milk (0.25 g lactose) per kg of body weight. On the basis of breath H₂ tests in 15 control subjects with normal oral lactose tolerance tests, a response factor of 20 ppm was selected as the upper limit for lactose absorbers. Of the 60 subjects in the study group, 36 (60%) were classified as lactose malabsorbers since they had a response factor of 20 ppm or greater of breath H₂. Only 3 of 20 children (15%) who were under the age of 12 yr were nondigesters of the small lactose dose used in this study. Approximately 82 percent (82.5%) of subjects who were 13 yr and older were lactose malabsorbers. Adolescence appears to be the period in which malabsorption of lactose becomes evident in Native North Americans.Supported by the Nutrition Foundation, Inc., New York, New York; Biomedical Sciences Support Grant (USPH) 5-S05-RR7077 to The Research Foundation, Oklahoma State University.