Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022104 (irritable bowel syndrome)
 8,033 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Breath methane was studied in 394 subjects. Among 152 controls, 50.0% produced methane--42.1% of males and 57.9% of females. One hundred sixteen patients with gastrointestinal diseases were studied. Among 32 with Crohn's disease, only 2 (6.1%) produced methane, as well as 16 of 51 ulcerative colitis patients (31.4%) and 11 of 32 patients with the irritable bowel syndrome (34.4%). Breath methane is thus unusual in Crohn's disease. After bowel cleansing for colonoscopy or surgery, 15 of 18 methane producers became nonproducers, whereas after antibiotic treatment, 24 of 30 producers sustained their methane-producing status. After gentamycin and cephazolin therapy, methane production was abolished in three of eight patients. Slight spontaneous variations in methane production were also noticed with two of 23 control subjects, becoming nonproducers on restudy after 10-25 months. Thus gastrointestinal diseases, bowel cleansing and, to a much lesser degree, antibiotic therapy, affect methane production.
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PMID:Factors affecting methane production in humans. Gastrointestinal diseases and alterations of colonic flora. 381 80

This study investigated a possible role for primary bile acid in the control of methanogenesis in the human colon. Production of hydrogen and methane was measured in anaerobic faecal cultures derived from faeces of six 'non-methanogenic' and three methanogenic healthy humans. Using a sensitive technique for gas measurement, methane was detected in all faecal cultures, including those from 'non-methanogenic' humans. Bile acid inhibited methanogenesis in a dose-response fashion in the in vitro 'non-methanogenic' and methanogenic faecal cultures. Inhibition was significant at bile acid concentrations > 0.05%. Methanogenesis correlated with methanogen (methanogenic bacteria) numbers. If this inhibition occurs in vivo, then it would explain much of the epidemiology of non-methanogenesis in humans. From an analysis of net hydrogen production by the faecal cultures, it is inferred that bile acid inhibits other hydrogen-consuming bacteria in addition to methanogens. These in vitro data suggest a major role for bile acid in the accumulation of hydrogen gas in the colon. Possible links between bile acid induced accumulation of gas and irritable bowel syndrome are discussed.
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PMID:A possible role for bile acid in the control of methanogenesis and the accumulation of hydrogen gas in the human colon. 800 41

In a double-blind, crossover study, we determined whether microencapusulated pancreatic enzymes reduce postprandial symptoms experienced by healthy volunteers after ingestion of a high calorie, high fat meal. At 7 AM, 18 subjects ingested 185 g of cookies (1196 calories and 72 g of fat) with three pancrelipase capsules or a placebo. The severity of gastrointestinal symptoms and flatus passages were recorded for 15-17 hr, and end-alveolar samples were obtained hourly for 10 hr. Ingestion of pancreatic supplements was associated with a significant (P = 0.049) reduction in bloating over the entire recording period, and with significant reductions in bloating, gas, and fullness during the dinner to bedtime period. Pancreatic supplements had no significant effect on breath H2 or CH4 concentration. The finding that pancreatic supplements reduce postprandial symptoms in healthy subjects suggests that these supplements also might be beneficial in irritable bowel syndrome.
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PMID:Pancreatic supplements reduce symptomatic response of healthy subjects to a high fat meal. 1048 12

It has recently been determined that there is an increased prevalence of bacterial overgrowth in IBS. Since there are two gases (hydrogen and methane) measured on lactulose breath testing, we evaluated whether the different gas patterns on lactulose breath testing coincide with diarrhea and constipation symptoms in IBS and IBD. Consecutive patients referred to the gastrointestinal motility program at Cedars-Sinai Medical Center for lactulose breath testing were given a questionnaire to evaluate their gastrointestinal symptoms. Symptoms were graded on a scale of 0-5. Upon completion of the breath test, the results were divided into normal, hydrogen only, hydrogen and methane, and methane only positive breath tests. A comparison of all subjects and IBS subjects was undertaken to evaluate diarrhea and constipation with regards to the presence or absence of methane. This was further contrasted to Crohn's and ulcerative colitis (UC) patients in the database. After exclusion criteria, 551 subjects from the database were available for comparison. Of the 551 subjects (P < 0.05, one-way ANOVA) and in a subgroup of 296 IBS subjects (P < 0.05, one-way ANOVA), there was a significant association between the severity of reported constipation and the presence of methane. The opposite was true for diarrhea (P < 0.001). If a breath test was methane positive, this was 100% associated with constipation predominant IBS. Furthermore, IBS had a greater prevalence of methane production than Crohn's or UC. In fact, methane was almost nonexistent in the predominantly diarrheal conditions of Crohn's and UC. In conclusion, a methane positive breath test is associated with constipation as a symptom.
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PMID:Methane production during lactulose breath test is associated with gastrointestinal disease presentation. 1264 95

We have previously shown that methane on lactulose breath test (LBT) is highly associated with constipation in IBS and that methane gas itself slows small bowel transit in dogs. Previous studies suggest that serotonin may have a role in the control of transit in IBS. In this study, we aim to evaluate the role of serotonin in methane producing IBS subjects. Rome I-positive IBS subjects were recruited into the study after exclusion criteria were met. A fasting LBT was performed after subjects filled out a questionnaire rating the degree of constipation and diarrhea. Within 7 days of this test, subjects returned fasting for determination of serotonin before and after a 75-g oral glucose meal. The serotonin response was compared between hydrogen and methane producing IBS subjects. After 2 subjects were excluded for inadequate blood samples, 18 subjects completed the study. Four of 18 subjects produced methane. The postprandial serotonin level in methane producing IBS subjects was lower than in hydrogen producers (P < 0.05). Methane producers had a reduction in serotonin after glucose. Methane producing IBS subjects have reduced postprandial serotonin. Whether methane is a surrogate marker of constipation or contributing to the reduced serotonin remains to be determined.
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PMID:IBS subjects with methane on lactulose breath test have lower postprandial serotonin levels than subjects with hydrogen. 1499 40

Abnormal fermentation may be an important factor in irritable bowel syndrome (IBS). Gastroenteritis or antibiotic therapy may damage the colonic microflora, leading to increased fermentation and the accumulation of gas. Gas excretion may be measured by whole-body calorimetry but there has only been one such study on IBS to date. We aimed to assess the relationship between IBS symptoms and fermentation rates in IBS. A purpose-built, 1.4-m3, whole-body calorimeter was used to assess excretion of H2 and CH4 in IBS subjects while consuming a standard diet and, again, after open randomization on either the standard diet together with the antibiotic metronidazole or a fiber-free diet to reduce fermentation. Metronidazole significantly reduced the 24-hr excretion of hydrogen (median value compared to the control group, 397 vs 230 ml/24 hr) and total gas (H2 + CH4; 671 vs 422 ml/min) and the maximum rate of gas excretion (1.6 vs 0.8 ml/min), as did a no-fiber polymeric diet (hydrogen, 418 vs 176 ml/min; total gas, 564 vs 205 ml/min; maximum rate of gas excretion, 1.35 vs 0.45 ml/min), with a significant improvement in abdominal symptoms. IBS may be associated with rapid excretion of gaseous products of fermentation, whose reduction may improve symptoms.
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PMID:Do interventions which reduce colonic bacterial fermentation improve symptoms of irritable bowel syndrome? 1584 15

The presence of methane on lactulose breath test among irritable bowel syndrome (IBS) subjects is highly associated with the constipation-predominant form. Therefore, we set out to determine whether methane gas can alter small intestinal motor function. In dogs, small intestinal fistulae were created to permit measurement of intestinal transit. Using a radiolabel, we evaluated transit during infusion of room air and subsequently methane. In this model, small intestinal infusion of methane produced a slowing of transit in all dogs by an average of 59%. In a second experiment, guinea pig ileum was pinned into an organ bath for the study of contractile activity in response to brush strokes applied to the mucosa. The force of contraction was measured both orad and aborad to the stimulus. The experiment was repeated while the bath was gassed with methane. Contractile activities orad and aborad to the stimulus were significantly augmented by methane compared with room air (P < 0.05). In a third experiment, humans with IBS who had undergone a small bowel motility study were compared such that subjects who produced methane on lactulose breath test were compared with those producing hydrogen. The motility index was significantly higher in methane-producing IBS patients (1,851 +/- 861) compared with hydrogen producers (1,199 +/- 301) (P < 0.05). Therefore, methane, a gaseous by-product of intestinal bacteria, slows small intestinal transit and appears to do so by augmenting small bowel contractile activity.
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PMID:Methane, a gas produced by enteric bacteria, slows intestinal transit and augments small intestinal contractile activity. 1629 52

Recent studies have shown that normalization of the lactulose breath test (LBT) with neomycin leads to a significant reduction in irritable bowel syndrome (IBS) symptoms. This subanalysis was done on the constipation-predominant IBS subgroup of patients (C-IBS) to test the ability of neomycin to improve constipation and its correlation with the elimination of methane on breath test. IBS subjects underwent LBT in a blinded fashion. They were then randomly allocated to neomycin or placebo groups. For the purpose of this analysis, only the C-IBS subjects were identified. They were then evaluated for global improvement, abdominal pain, and constipation severity. The ability of neomycin to eliminate methane and its associated improvement in constipation was also determined. One hundred eleven subjects meeting Rome I criteria for IBS were included in the study. Thirty-nine of these had C-IBS. Of these, 20 received placebo and 19 received neomycin. With neomycin, a global improvement of 36.7+/-7.9% was seen, compared to 5.0+/-3.2% for placebo (P < .001) in the intention-to-treat analysis. Constipation was improved by 32.6+/-9.9% with neomycin compared to 18.7+/-7.2% for placebo (P=.26). Of the original 111 subjects, 12 demonstrated methane on breath test. All 12 of these patients were constipation predominant. In the methane producers receiving neomycin or placebo, improvement in constipation was significantly greater in those receiving neomycin (44.0+/-12.3%) compared to placebo (5.0+/-5.1%) (P < .05). Treatment with neomycin improves constipation in C-IBS. This improvement depends on the presence and elimination of methane on breath test.
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PMID:Neomycin improves constipation-predominant irritable bowel syndrome in a fashion that is dependent on the presence of methane gas: subanalysis of a double-blind randomized controlled study. 1683 17

Irritable bowel syndrome (IBS) is a complex, yet common diagnosis in gastroenterology. Recent data suggest the increasing importance of bacteria in the pathophysiology of IBS. Some studies have shown that IBS can be precipitated by an acute case of gastroenteritis. These pathogenic organisms may contribute to long-term gut dysfunction. In another line of effort, a growing body of evidence links IBS to the presence of excessive bacteria in the small bowel, called bacterial overgrowth. Although the means by which this is determined have been indirect, studies demonstrating the benefit of unabsorbed antibiotics suggest that reduction in gut flora is important. Further work has also examined bacterial overgrowth in the context of the various symptoms of patients with IBS. These symptom complexes include constipation, diarrhea, and alternating forms of the condition. Although this idea seems initially counterintuitive, it has been demonstrated that the fermentation of methane in the gut is associated with and can result in the slowing of intestinal transit, resulting in constipation. In this review, these topics are discussed and outlined.
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PMID:Bacteria and irritable bowel syndrome: the evidence for small intestinal bacterial overgrowth. 1683 42

An overlap of symptoms in irritable bowel syndrome (IBS) exists across subtype groups. Symptoms include intestinal gas, diarrhea, dyspepsia, bloating, abdominal pain, and constipation. The unifying symptom may be excessive intestinal gas as a by-product of intestinal microbial fermentation. Abnormal fermentation of food takes place when gut microbes expand proximally into the small intestine instead of being confined predominantly to the colon. Such proximal expansion of indigenous gut microbes or small intestinal bacterial overgrowth (SIBO) may lead to activation of host mucosal immunity and an increase in intestinal permeability to result in flu-like extra-intestinal symptoms that accompany the classic IBS symptoms of altered bowels. The presence of methane on lactulose breath testing is associated with constipation-predominant IBS. Antibiotic therapy may be appropriate to treat underlying SIBO in IBS patients. Seventy-five percent improvement of IBS symptoms was reported in a double-blind, placebo-controlled study once antibiotics succeeded in treating bacterial overgrowth. Once a good clinical response and normalization of the lactulose breath test are achieved, a prokinetic agent may be used to stimulate phase III of interdigestive motility to delay relapse of bacterial overgrowth.
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PMID:Bacterial concepts in irritable bowel syndrome. 1771 56


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