The influence of peripheral vascular disease on methanogenesis in man.

Methane is produced by anaerobic bacterial metabolism in the colon and is excreted in the breath of only a proportion of healthy adults. Factors influencing methane excretion have still to be elucidated. The colonic vascular circulation may influence the intestinal environment facilitating growth of methanogens. The incidence of breath methane excretion has been investigated in patients with peripheral vascular disease and a control patient group. The proportions of subjects excreting methane in the control hospital group (43%) and in patients with predominantly femoro-popliteal disease (30%) were significantly less than in patients with predominantly aorto-iliac disease (83%) (P less than 0.005 and P less than 0.001, respectively). The presence of abdominal aortic arterial disease appears to be associated with a high incidence of methane excretion.