Interrelationships between age, total dietary fiber intake and breath methane in humans

Abstract

In western populations the prevalence of methane producers (MP) is 30–50%. Studies related to dietary intakes of MP are lacking. The aim of this study was to compare dietary intakes in MP and methane nonproducers (MNP). In 122 healthy subjects, breath gases were analysed and 3-day food records were collected to assess the nutrient intakes. The 63 MP were significantly older than the 59 MNP (48.9±2.0 vs 38.3±2.2 y: P<0.001) and breath methane concentrations were weakly correlated with age in MP (r=0.268, P=0.03). There were no differences in macronutrient intakes between MP and MNP. A positive correlation was observed between age and total dietary fibre intake in MP (r = 0.400, P = 0.001) and MNP (r= 0.358, P = 0.005). Mean dietary fibre intake in MP was significantly higher than that in MNP (23.2±1.4 vs 18.1±1.3 gm; P < 0.01), but the difference was not significant after adjusting for age. Dietary fibre intake was positively correlated with breath methane in MP (r = 0.309, P = 0.01). These results suggest that by providing a substrate for bacteria in the distal colon, dietary fibre intakes may enhance methanogenesis as MP become older and possibly play a prebiotic role.