All Lactase Preparations Are Not the Same: Results of a Prospective, Randomized, Placebo-Controlled Trial

Objective: To compare the efficacy of three commercially available oral lactase preparations in adults with lactose intolerance. Methods: Design—Prospective, randomized, placebo-controlled trial. Setting—Outpatient study in a General Clinical Research Center. Subjects—Ten lactose-intolerant healthy volunteers were challenged with ice cream containing 18 g of lactose. Lactase or placebo was given immediately prior to challenge. Measurements—Symptoms and breath hydrogen excretion were recorded for 3 h following lactose challenge. Results: The three products differed in their abilities to influence symptoms and breath hydrogen excretion. Only Lactaid reduced the breath hydrogen excretion with lactose (mean peak, area under the curve and cumulative breath hydrogen excretion) ( P < 0.05). Lactrase and Dairy Ease influenced symptoms: Lactrase reduced pain, bloating and total symptomatic scores ( P < 0.05), whereas Dairy Ease only reduced pain ( P < 0.05). Lactaid administration did not reduce symptoms. Conclusion: In lactose-intolerant subjects, the available lactase preparations differ in their ability to improve both breath hydrogen excretion and symptoms. Lactrase may be the product of choice for achieving symptomatic improvement.     

Stability of human methanogenic flora over 35 years and a review of insights obtained from breath methane measurements.

BACKGROUND & AIMS: Breath methane measurements reflect the in situ activity of the methanogenic colonic flora. Thirty-five years ago we found that 34% of healthy adult subjects were methane producers (breath methane level >1 ppm above atmospheric methane levels). The current study presents a new survey of breath methane levels designed to determine if the activity of the methanogenic flora has changed over the past 35 years. In addition, we review insights into the methanogenic flora that have resulted from breath methane measurements. METHODS: The end-alveolar breath methane concentrations of 212 healthy adults living in the Minneapolis area were determined via gas chromatography. The influence of sex, age, and bowel movement frequency on methane production was assessed. RESULTS: The findings that 36.4% of participants were methane producers, with a mean methane concentration in these producers of 16.6 ppm, are strikingly similar to the values of 33.6% and 15.2 ppm observed 35 years ago. Neither sex nor age showed a statistically significant relationship to methane production. There was a negative correlation between frequency of bowel movements and breath methane concentration in methane producers. CONCLUSIONS: The activity of the methanogenic flora of healthy adults remained remarkably stable over the past 35 years despite widespread antibiotic use and dietary changes. A literature review revealed that many associations have been shown between methane production and clinical states, but it remains to be determined if methanogens actively influence human physiology or are simply a marker of colonic function.     

Lactase deficiency and lactose intolerance-related symptoms in adult healthy subjects from western France]

The prevalence of lactase deficiency (LD) and lactose intolerance is not well known in France. Using breath hydrogen and methane analysis after 50 g oral lactose load, we investigated the prevalences of LD, lactose intolerance, and methane producer status in 102 healthy adults born in western France, and we examined the relationships between these parameters and the daily milk consumption. In 10 subjects with LD and lactose intolerance, we studied the reproducibility of the lactose hydrogen breath test results for the diagnosis of LD and lactose intolerance and estimated the quantity of lactose malabsorbed in comparison with the lactulose hydrogen breath test. The prevalence of LD was 23.4 percent and symptoms of lactose intolerance were observed in 50 percent of the 24 subjects with LD. The daily milk consumption was not significantly different in the 24 subjects with LD and in the 78 subjects without LD (281 +/- 197 vs 303 +/- 217 ml/24 h). The prevalence of methane producer status was 42.1 percent. The symptomatic group of lactose malabsorbers (n = 12) was characterized by a shorter lactose mouth to caecum transit time (39 +/- 20 vs 88 +/- 48 min; P less than 0.05), and more marked hydrogen production (6.1 +/- 2.3 vs 3.4 +/- 2.4 10(3) ppm.min; P less than 0.04). In the 10 subjects with LD and lactose intolerance, the hydrogen breath test was reproducible for diagnosis of LD and lactose intolerance, and for hydrogen production. The quantity of lactose malabsorbed was 60 percent. In France, symptoms of lactose intolerance are not severe and do not affect the daily consumption of milk and dairy products.     

Circadian rhythm of breath hydrogen in young women

Breath hydrogen levels, which reflect colonic fermentation of undigested starches, are usually low in the fasted state. Fasting levels of breath hydrogen are important for estimation of oro-cecal transit time and diagnosis of lactase deficiency. In young women, however, fasting levels of breath hydrogen are high. To clarify the reason for this, we studied the circadian pattern of breath hydrogen and the effect of α-D-galactosidase on fasting breath hydrogen in one study, and the effect of sleep deprivation on fasting breath hydrogen in another study, in 13 women students aged 21–23 years. In the first study, two breath samples were collected, one in the evening and the other the next morning. On another occasion, α-D-galactosidase was given before dinner and breath samples were collected the next morning. In the second study, the circadian rhythm of breath hydrogen was assessed for 3 days and the subjects were deprived of sleep on the second night. Breath samples were collected every 30 min, except during the second night when samples were collected at 1-h intervals. Fasting breath hydrogen was 24 ± 3.9 ppm (mean ± SE), which did not differ from the value for the previous night. α-D-galactosidase significantly decreased fasting breath hydrogen levels, to 17 ± 2.4 ppm (P < 0.05). There was a clear circadian pattern of breath hydrogen, high in the morning and decreasing to the nadir by 16:00. After dinner, the level increased again and stayed high during the night. Sleep deprivation did not affect fasting levels of breath hydrogen. High fasting breath hydrogen levels in young women followed a circadian pattern and this may have been due, in part, to an high intake of dietary fiber on the previous day. (Received Sept. 16, 1997; accepted Jan. 23, 1998)     

Breath Methane Excretion and Intestinal Methanogenesis in Children and Adults in Rural Nigeria

Breath methane excretion was measured in 274 healthy subjects from 2 rural communities in northern Nigeria. Studies in 24 adults showed a normal faecal flora with no enteric pathogens. Breath methane was detected in 122 (77%) of 159 adults, 19 (40%) of 47 older children (2-6 years), and 4 (8%) of 68 young children (<2 years). Women were slightly more commonly breath methane-positive than men (82% versus 75%, respectively). Hyperventilation did not influence the specificity of the breath methane assay, although levels were circa 30% lower after deliberate hyperventilation. Methanogens were estimated by enrichment culture of faeces from 49 subjects. Of the subjects 76% had faecal methanogens estimated at ≥10²/g, 45% at ≥10⁴/g, and 16% at ≥10⁶/g. There was no significant difference in distribution of methanogenic cultures between different age or tribal groups, and there were no obvious correlations between breath methane excretion and either the faecal carriage of methanogens per se or numbers present.     

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.     

Seventy-five gram glucose tolerance test to assess carbohydrate malabsorption and small bowel bacterial overgrowth

AIM: To investigate non-invasively the incidence of absorption of carbohydrates in diabetic patients during an oral glucose tolerance test (OGTT) and to determine whether malabsorption may be associated with insulin secretion and insulin resistance. METHODS: A standard 75-g OGTT was performed in 82 diabetic patients. The patients received 75 g of anhydrous glucose in 225 mL of water after an overnight fasting and breath samples were collected at baseline and up to 120 min after ingestion. Breath hydrogen and methane concentrations were measured. Blood glucose and serum insulin concentrations were measured before ingestion and at 30, 60, 90, 120 min post-ingestion. RESULTS: When carbohydrate malabsorption was defined as subjects with an increase of at least 10 ppm (parts per million) in hydrogen or methane excretion within a 2-h period, 28 (34%) had carbohydrate malabsorption. According to the result of increased breath test, 21 (75%) patients were classified as small bowel bacterial overgrowth and 7 (25%) as glucose malabsorption. Patients with carbohydrate malabsorption were older and had poor glycemic control as compared with those without carbohydrate malabsorption. The HOMA value, the sum of serum insulin during the test and the Ainsulin/Aglucose ratio were greater in patients with carbohydrate malabsorption. CONCLUSION: Insulin resistance may be overestimated by using these markers if the patient has carbohydrate malabsorption, or that carbohydrate malabsorption may be present prior to the development of insulin resistance. Hence carbohydrate malabsorption should be taken into account for estimating insulin resistance andβ-cell function.     

Effect of Lactobacillus plantarum 299v on colonic fermentation and symptoms of irritable bowel syndrome

A number of recent clinical trials have promoted the use of probiotic bacteria as a treatment for irritable bowel syndrome (IBS). The recent demonstration of abnormal colonic fermentation in some patients with this condition provides an opportunity for the objective assessment of the therapeutic value of these bacteria. This study was designed to investigate the effects of Lactobacillus plantarum 299V on colonic fermentation. We conducted a double-blind, placebo-controlled, cross-over, four-week trial of Lactobacillus plantarum 299V in 12 previously untreated patients with IBS. Symptoms were assessed daily by a validated composite score and fermentation by 24-hr indirect calorimetry in a 1.4-m³ canopy followed by breath hydrogen determination for 3 hr after 20 ml of lactulose. On placebo, the median symptom score was 8.5 [6.25–11.25 interquartile range (IQR)], the median maximum rate of gas production was 0.55 ml/min (0.4–1.1 IQR), and the median hydrogen production was 189.7 ml/24 hr (118.3–291.1 IQR). On Lactobacillus plantarum 299V the median symptom score was 8 (6.75–13.5 IQR), the median maximum rate of gas production 0.92 ml/min (0.45–1.5 IQR), and the median hydrogen production 208.2 ml/24 hr (146–350.9 IQR). There was no significant difference. Breath hydrogen excretion after lactulose was reduced by the probiotic (median at 120 min, 6 ppm; placebo, 17 ppm; P = 0.019). In conclusion, Lactobacillus plantarum 299V in this study did not appear to alter colonic fermentation or improve symptoms in patients with the irritable bowel syndrome.     

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.     

Carbohydrate Malabsorption: Quantification by Methane and Hydrogen Breath Tests

Rumessen JJ, Nordgaard-Andersen I, Gudmand-Høyer E. Carbohydrate malabsorption: quantification by methane and hydrogen breath tests. Scand J Gastroenterol 1994;29:826-832.

Background: Previous studies in small series of healthy adults have suggested that parallel measurement of hydrogen and methane resulting from gut fermentation may improve the precision of quantitative estimates of carbohydrate malabsorption. Systematic, controlled studies of the role of simultaneous hydrogen and methane measurements using end-expiratory breath test techniques are not available. Methods: We studied seven healthy, adult methane and hydrogen producers and seven methane non-producers by means of end-expiratory breath test techniques. Breath gas concentrations and gastrointestinal symptoms were recorded at intervals for 12 h after ingestion of 10,20, and 30 g lactulose. Results: In the seven methane producers the excretion pattern was highly variable; the integrated methane responses were disproportional and not reliably reproducible. However, quantitative estimates of carbohydrate malabsorption on the basis of individual areas under the methane and hydrogen excretion curves (AUCs) tended to improve in methane producers after ingestion of 20 g lactulose by simple addition of AUCs of methane to the AUCs of the hydrogen curves. Estimates were no more precise in methane producers than similar estimates in non-producers. Gastrointestinal symptoms increased significantly with increasing lactulose dose; correlation with total hydrogen and methane excretion was weak. Conclusions: Our study suggests that in methane producers, simple addition of methane and hydrogen excretion improves the precision of semiquantitative measurements of carbohydrate malabsorption. The status of methane production should, therefore, be known to interpret breath tests semiquantitatively. The weak correlation between hydrogen and methane excretion and gas-related abdominal complaints suggests that other factors than net production of these gases may be responsible for the symptoms.     

Breath testing to evaluate lactose intolerance in irritable bowel syndrome correlates with lactulose testing and may not reflect true lactose malabsorption

OBJECTIVES: An increased prevalence of lactose intolerance is seen in irritable bowel syndrome (IBS). Recently, we demonstrated a high prevalence of abnormal lactulose breath test results in IBS suggesting bacterial overgrowth. Because symptoms of lactose intolerance result from bacterial fermentation, the purpose of this study was to determine whether an abnormal lactose breath test is reflective of malabsorption or early presentation to bacteria. METHODS: Subjects with diarrhea-predominant IBS were enrolled. On day 1, subjects underwent a lactulose breath test after an overnight fast. Within 1 wk, subjects returned after fasting for a lactose breath test with simultaneous blood glucose measurements every 15 min to complete a lactose tolerance test (LTT). Symptoms were evaluated 3 h after lactose administration. RESULTS: Twenty subjects completed the study. One subject inadvertently received dextrose through the intravenous and was excluded. Of the remaining 19 subjects, three (16%) had an abnormal LTT suggesting malabsorption. In all, 10 subjects (53%) had an abnormal lactose breath test, 14 (74%) had an abnormal lactulose breath test, and 11 (58%) had symptoms after lactose administration. The agreement with symptoms was moderate (kappa = 0.47) and fair (kappa = 0.24) when compared to the lactose breath test and LTT, respectively. There was a fair correlation between lactose breath test and LTT (kappa = 0.29). However, lactose breath test hydrogen levels >166 ppm were universally predictive of abnormal LTT. Finally, a significant correlation was seen between the hydrogen production on lactose and lactulose breath test (r = 0.56, p = 0.01). CONCLUSIONS: Lactose breath testing in IBS subjects does not seem to reflect malabsorption; it may be an indicator of abnormal lactulose breath test, suggesting bacterial overgrowth.     

Enzyme replacement for lactose malabsorption using a beta-D-galactosidase

We evaluated 10 healthy symptomatic lactose malabsorbers for effect of an oral beta-D-galactosidase derived from Aspergillus oryzae (Lactrase, Kremers Urban Company, Milwaukee, WI, U.S.A.) on symptom and breath hydrogen response to challenge with 50 g lactose. Basally and at 30-min intervals for 8 h after lactose challenge, end-alveolar breath samples were collected and analyzed for hydrogen using gas chromatography. Symptoms were scored at 30 min and hourly for 8 h, rating bloating, cramps, nausea, pain, diarrhea, and flatulence. Four challenges were performed on 4 separate days with at least 3 days between challenges. The first two challenges served as baselines. Just before ingestion of 50 g powdered lactose dissolved in 200 ml water, beta-D-galactosidase capsules were given orally as a 250-mg dose for the third challenge and a 500-mg dose for challenge 4. Hydrogen excretion, quantified by using a trapezoidal method for computing area under the discontinuous curve of breath hydrogen concentration, was decreased in subjects receiving beta-D-galactosidase (base-line I, 346.0 ppm/h; baseline II, 367.2 ppm/h; 250-mg galactosidase 208.2 ppm/h; 500-mg galactosidase, 178.0 ppm/h; p less than or equal to 0.05). Other analyzed parameters of H2 excretion were also decreased. Analysis of symptom response scores showed a dose-related decrease for bloating and flatus (p less than or equal to 0.05) and no statistical difference in the other assessed symptoms. We conclude that beta-D-galactosidase from Aspergillus oryzae, when given just before ingestion of lactose by lactose malabsorbers, can produce a dose-dependent reduction (statistically significant for the 500-mg dose) in breath hydrogen excretion, bloating, and flatus.     

Epidemiology of small bowel bacterial overgrowth and rice carbohydrate malabsorption in Burmese (Myanmar) village children.

Breath hydrogen tests were performed after a rice meal (3 g of cooked rice/kg of body weight, equivalent to 1 g of carbohydrate/kg of body weight) on 256 village children (age range 1-59 months) who were known hydrogen (H2) producers. Anthropometric measurements were made every three months and growth rates were calculated. A breath H2 excretion pattern that suggested small bowel bacterial overgrowth (SBBO), which was recognized as a transient maximum level of 10 ppm or more at 20-, 40-, or 60-min breath samples following the rice meal, was present in 53 (20.7%) children, and was more frequent in children 36-47 and 48-59 months old. This breath H2 excretion pattern was detected in 48 (33.3%) of 144 children who were rice malabsorbers (greater than 10 ppm H2 above baseline values in one of the breath samples taken between 90 and 240 min), and in only five (4.5%) of 112 rice absorbers. Children who had SBBO had a high relative risk (10.7) of being rice malabsorbers. Rice malabsorbers have a high relative risk (59.7) of having faltered growth, accompanied by a large etiologic fraction (94%). This same risk (6.68) and an etiologic fraction of 62% exist in children with untreated SBBO. These findings emphasize the need for interventions aimed at reducing the prevalence of SBBO or similar conditions as detected by the breath H2 excretion pattern to prevent rice malabsorption and growth faltering.     

Breath hydrogen response to lactulose in healthy subjects: relationship to methane producing status.

In order to assess the relationship between methane (CH4) producing status and the breath excretion of hydrogen (H2) in healthy subjects, breath CH4 and H2 were simultaneously measured for 14 hours after oral ingestion of 10 g lactulose in 65 young volunteers. Forty were breath CH4 producers and 25 were not. Statistically significant differences were observed between both groups, with lower values for CH4 producers recorded for the following parameters: fasting basal value of breath H2 (8.1 (4.9) v 5.2 (3.7) ppm, p less than 0.05), mouth-to-caecum transit time (68 (24) v 111 (52) min, p less than 0.005), and breath H2 production measured as area under the curve 13.1 (6.9) v 8.8 (3.8) 10(3) ppm/min, p less than 0.02). There was no significant correlation between individual production of breath H2 and CH4. These results indicate that the response to lactulose depends on breath CH4 producing status. In clinical practice, defining normal values of mouth-to-caecum transit time without knowledge of breath CH4 producing status may lead to misinterpretation of the H2 breath test.     

Effect of Guar, Pectin, Psyllium, Soy Polysaccharide, and Cellulose on Breath Hydrogen and Methane in Healthy Subjects

Different types of dietary fiber are fermented to various extents in vitro, but little is known about the effects of fiber on breath hydrogen and methane levels in vivo. Therefore, we studied the effects on breath hydrogen and methane of 15 g of guar, pectin, psyllium, soy polysaccharide, or cellulose in eight healthy subjects over a 12-h period. None of the fibers had a significant effect on breath hydrogen or methane concentrations, compared with the control (fasting). The four methane producers had lower breath hydrogen levels than the nonproducers 1 h after 15 g of lactulose (3 +/- 1 vs. 42 +/- 9, p less than 0.005) and 5-12 h after the different fibers (3.3 vs. 4.8 ppm; pooled SEM = 0.8; p less than 0.025). When the methane responses of the methane producers were expressed as increments relative to the control, there were small differences between treatments, with guar producing a larger response, 8.2 +/- 3.3 ppm, than cellulose, -2.9 +/- 2.3 ppm (p less than 0.05). The incremental methane responses of the different fibers in vivo were related to the previously reported production of propionic acid (r = 0.94, n = 5, p less than 0.02) and methane (r = 0.93, n = 4, NS) from in vitro fermentation of the same fibers. We conclude that methane producers have lower breath hydrogen levels than nonproducers. Purified fermentable and nonfermentable dietary fibers have no effect on breath hydrogen levels over 12 h in subjects previously consuming a normal diet. However, fermentable fibers may produce small increases in breath methane in methane-producing subjects.     

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.     

Interval sampling of breath hydrogen (H2) as an index of lactose malabsorption in lactase-deficient subjects

Interval sampling of breath hydrogen content was used in lactose malabsorbers: (1) to compare hydrogen responses following increasing oral doses of lactose in milk and aqueous solutions; (2) to determine the reproducibility of interval breath sampling, and (3) to compare carbohydrate malabsorption following ingestion of either regular milk or milk containingLactobacillus acidophilus. Significant differences in breath hydrogen responses due to increasing amounts of lactose in milk and aqueous solutions were observed. The individual breath hydrogen responses were reproducible using the same lactose dose on different days. There was no significant difference in breath hydrogen responses or symptoms following administration of either regular milk or milk containingLactobacillus acidophilus. Breath hydrogen sampling at intervals, as performed in these studies, provides a sensitive and reproducible index of lactose malabsorption.Supported by the Oklahoma Agricultural Experiment Station, Stillwater, Oklahoma, and the Veterans Administration.     

Using breath tests wisely in a gastroenterology practice: an evidence-based review of indications and pitfalls in interpretation

Breath tests are a simple and safe alternative to more invasive investigation strategies for many gastroenterological conditions. Both the hydrogen breath tests and the new 13C stable radioisotope breath tests are nonradioactive and safe in children and pregnancy. The range of diseases that can be identified include Helicobacter pylori infection, lactose and fructose intolerance, bacterial overgrowth, bile salt wastage, pancreatic insufficiency, liver dysfunction, and abnormal small bowel transit. In this review, the physiology supporting these tests and the principles of normal gas dynamics in the gut are briefly reviewed and then related to the test preparation and interpretation in two parts: 1) detection of H. pylori and 2) small bowel, pancreatic, and hepatobiliary disorders. A MEDLINE search reviewing all English language abstracts from 1966 to March, 2001 was performed, with an additional review of abstracts from major national meetings from 1997 to 2001. Using the information from this review, the performance characteristics of the various tests were detailed, and an attempt is made to provide some literature-based guidance regarding their indications and limitations. The interpretation of "flat" breath tests and the selective use of methane collection and colonic alkalinization are discussed. Breath tests are valuable tools that are, in general, underutilized in evaluating dyspepsia and functional bloating and diarrhea, as well as suspected malabsorption, including lactose intolerance.     

Fecal skatole and indole and breath methane and hydrogen in patients with large bowel polyps or cancer

Summary The object of this study was to explore the use of fecal skatole and indole and breath methane and hydrogen as metabolic markers of the anaerobic colonic flora in patients with unresected large bowel cancer or polyps. Patients with descending or sigmoid colon cancer were more likely to be breath methane excretors than control subjects, patients with proximal colon cancer, and patients with rectal cancer. Control subjects excreting breath methane excreted less fecal skatole than breath methane excretors in the following groups: patients with adenomatous polyps, all patients with colorectal cancer, patients with proximal colon cancer, patients with descending and sigmoid colon cancer, and patients with rectal cancer. These data suggest that fecal skatole excretion equal to or greater than 100 g/g feces might be useful to discriminate colorectal cancer patients from control subjects. Twenty-nine percent (8 of 28) of the cancer patients had both high skatole levels and breath methane excretion compared with only 2% (1 of 41) of the control subjects (P<0.01).Supported by Public Health Service Grant CA-29056 from the National Cancer Institute     

Breath hydrogen and methane levels in a patient with volvulus of the sigmoid colon

Volvulus of the large bowel is the third most common cause of colonic obstruction. A patient with colonic obstruction or delayed small intestinal transit may frequently have bacterial overgrowth and increased breath hydrogen (H(2)) and/or methane (CH(4)) excretion because the bacterium can contact with food residues for a longer time. A 39 year old woman attended our hospital with complaints of abdominal pain and distension. This patient's abdominal radiograph showed an inverted U-shaped shadow. The fasting breath CH(4) level was 26 ppm. An endoscopic procedure was immediately carried out with suspected sigmoid colon volvulus, and detorsion was achieved. There was resolution of the sigmoid volvulus after colonoscopy, and breath CH(4) concentration in the next morning decreased to 10 ppm. A liquid meal was supplied at noon on the second hospital day. The breath CH(4) concentration increased markedly to 38 ppm at 18:00 although she had no abdominal symptoms. This value peaked at 42 ppm at 18:00 on the third hospital day and was gradually reduced to 20 ppm the next day. The breath H(2) concentration value kept a low level during fasting and increased markedly to 51 ppm the next day after a liquid meal was supplied. The next morning, fasting breath H(2) concentration rapidly decreased to 6 ppm. This suggests that changes in breath H(2) levels may reflect transient malabsorption after a liquid test meal is supplied. In conclusion, breath H(2) and CH(4) analysis may be another tool for evaluating the intestinal circumstances.