Methane, a gas produced by enteric bacteria, slows intestinal transit and augments small intestinal contractile activity

Abstract

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.

Methane-producing human subjects have higher serum glucose levels during oral glucose challenge than non-methane producers: a pilot study of the effects of enteric methanogens on glycemic regulation

“…The alteration between systemic availability of acetate and propionate produced during carbohydrate fermentation by methanogenic archaea has been suggested to influence doi: 10.7243/2053-3640-2-2 the blood lipid levels [35][36][37]. Using an animal model and ex vivo studies, our group has also shown that methane may also directly affect intestinal transit and gut neuromuscular function [38], findings which have since been confirmed by an independent group [39]. Slower gut motility could also result in increased time for nutrient absorption and energy harvest.…”

Methanogens in Human Health and Disease

“…In an animal model, direct infusion of methane into the small intestine produced a slowing of transit by an average of 59 % compared with room air ( 32 ). In part, the direct eff ect of methane on intestinal transit may be mediated through serotonin, a neurotransmitter that, among other functions, elicits peristaltic contractions in the gut.…”

Gastrointestinal microbiota in irritable bowel syndrome: present state and perspectives

“…The phylogenetically diverse and numerically abundant acetogenic bacteria have not yet been specifically addressed in any IBS cohort. Despite the fact that methane (CH 4 ), produced by methanogenic Archaea, has a proven causative and mechanistically described link to constipation (Pimentel et al, 2006), only a few studies have studied the methanogenic Archaea in IBS patients. Based on breath testing, both the prevalence and the rate of CH 4 production were lower in unsubtyped IBS patients than in HCs (Rana et al, 2009).…”