Effect of fibre, antispasmodics, and peppermint oil in the treatment of irritable bowel syndrome: systematic review and meta-analysis

Objective: To determine the effect of fibre, antispasmodics, and peppermint oil in the treatment of irritable bowel syndrome. Design: Systematic review and meta-analysis of randomised controlled trials. Data sources: Medline, Embase, and the Cochrane controlled trials register up to April 2008. Review methods: Randomised controlled trials comparing fibre, antispasmodics, and peppermint oil with placebo or no treatment in adults with irritable bowel syndrome were eligible for inclusion. The minimum duration of therapy considered was one week, and studies had to report either a global assessment of cure or improvement in symptoms, or cure of or improvement in abdominal pain, after treatment. A random effects model was used to pool data on symptoms, and the effect of therapy compared with placebo or no treatment was reported as the relative risk (95% confidence interval) of symptoms persisting. Results: 12 studies compared fibre with placebo or no treatment in 591 patients (relative risk of persistent symptoms 0.87, 95% confidence interval 0.76 to 1.00). This effect was limited to ispaghula (0.78, 0.63 to 0.96). Twenty two trials compared antispasmodics with placebo in 1778 patients (0.68, 0.57 to 0.81). Various antispasmodics were studied, but otilonium (four trials, 435 patients, relative risk of persistent symptoms 0.55, 0.31 to 0.97) and hyoscine (three trials, 426 patients, 0.63, 0.51 to 0.78) showed consistent evidence of efficacy. Four trials compared peppermint oil with placebo in 392 patients (0.43, 0.32 to 0.59). Conclusion: Fibre, antispasmodics, and peppermint oil were all more effective than placebo in the treatment of irritable bowel syndrome

Promotion of Intestinal Peristalsis by Bifidobacterium spp. Capable of Hydrolysing Sennosides in Mice

BACKGROUND:While there are a variety of identifiable causes of constipation, even idiopathic constipation has different possible mechanisms. Sennosides, the main laxative constituents of Daio, an ancient Kampo medicine, are prodrugs that are converted to an active principle, rheinanthrone, by intestinal microbiota. In this study, we aimed to determine the sennoside hydrolysis ability of lactic acid bacterial strains and bifidobacteria in the intestine and to investigate their effect on intestinal peristalsis in mice. METHODOLOGY/PRINCIPAL FINDINGS:A total of 88 lactic acid bacterial strains and 47 bifidobacterial strains were evaluated for their ability to hydrolyze sennosides. Our results revealed that 4 strains, all belonging to the genus Bifidobacterium, had strong sennoside hydrolysis ability, exhibiting a decrease of >70% of sennoside content. By thin-layer chromatography analysis, rheinanthrone was detected in the medium cultured with B. pseudocatenulatum LKM10070 and B. animalis subsp. lactis LKM512. The fecal sennoside contents significantly (P<0.001) decreased upon oral administration of these strains as compared with the control. Intestinal peristalsis activity was measured by the moved distance of the charcoal powder administered orally. The distance travelled by the charcoal powder in LKM512-treated mice was significantly longer than that of control (P<0.05). Intestinal microbiota were analysed by real-time PCR and terminal-restriction fragment length polymorphism. The diversity of the intestinal microbiota was reduced by kanamycin treatment and the diversity was not recovered by LKM512 treatment. CONCLUSION/SIGNIFICANCE:We demonstrated that intestinal peristalsis was promoted by rheinanthrone produced by hydrolysis of sennoside by strain LKM512 and LKM10070

Increased cholinergic contractions of jejunal smooth muscle caused by a high cholesterol diet are prevented by the 5-HT(4 )agonist – tegaserod

BACKGROUND: Excess cholesterol in bile and in blood is a major risk factor for the respective development of gallbladder disease and atherosclerosis. This lipid in excess negatively impacts the functioning of other smooth muscles, including the intestine. Serotonin is an important mediator of the contractile responses of the small intestine. Drugs targeting the serotonin receptor are used as prokinetic agents to manage intestinal motor disorders, in particular irritable bowel syndrome. Thus, tegaserod, acting on 5-HT(4 )receptor, ideally should obviate detrimental effects of excessive cholesterol on gastrointestinal smooth muscle. In this study we examined the effect of tegaserod on cholesterol-induced changes in the contractile responses of intestinal smooth muscle. METHODS: The effects of a high cholesterol (1%) diet on the in vitro contractile responses of jejunal longitudinal smooth muscle from Richardson ground squirrels to the cholinergic agonist carbachol were examined in the presence or absence of tetrodrodotoxin (TTX). Two groups of animals, fed either low (0.03%) or high cholesterol rat chow diet, were further divided into two subgroups and treated for 28 days with either vehicle or tegaserod. RESULTS: The high cholesterol diet increased, by nearly 2-fold, contractions of the jejunal longitudinal smooth muscle elicited by carbachol. These cholinergic contractions were mediated by muscarinic receptors since they were blocked by scopolamine, a muscarinic receptor antagonist, but not by the nicotinic receptor antagonist, hexamethonium. Tegaserod treatment, which did not affect cholinergic contractions of tissues from low cholesterol fed animals, abrogated the increase caused by the high cholesterol diet. With low cholesterol diet TTX enhanced carbachol-evoked contractions, whereas this action potential blocker did not affect the augmented cholinergic contractions seen with tissues from animals on the high cholesterol diet. Tegaserod-treatment removed the effects of a high cholesterol diet on neuronal muscarinic receptors, as the potentiating effect of TTX on carbachol-elicited contractions was maintained in these animals. CONCLUSION: A high cholesterol diet causes significant changes to cholinergic neurotransmission in the enteric nerves of the jejunum. The mechanisms by which these effects of cholesterol are reversed by tegaserod are unknown, but relate to removal of an inhibitory effect of cholesterol on enteric nerves