Anaerobic fermentation of the undigested
polysaccharide fraction of
carbohydrates produces
hydrogen in the intestine which is the substrate for methane production by intestinal methanogens.
Hydrogen and methane are excreted in the
flatus and in breath giving the opportunity to indirectly measure their production using breath testing. Although methane is detected in 30%-50% of the healthy adult population worldwide, its production has been epidemiologically and clinically associated with
constipation related diseases, like
constipation predominant
irritable bowel syndrome and chronic
constipation. While a causative relation is not proven yet, there is strong evidence from animal studies that methane delays intestinal transit, possibly acting as a neuromuscular transmitter. This evidence is further supported by the universal finding that methane production (measured by breath test) is associated with delayed transit time in clinical studies. There is also preliminary evidence that
antibiotic reduction of methanogens (as evidenced by reduced methane production) predicts the clinical response in terms of symptomatic improvement in patients with
constipation predominant
irritable bowel syndrome. However, we have not identified yet the mechanism of action of methane on intestinal motility, and since methane production does not account for all
constipation associated cases, there is need for high quality clinical trials to examine methane as a
biomarker for the diagnosis or as a
biomarker that predicts
antibiotic treatment response in patients with
constipation related disorders.