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

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 12 2 healthy subjects, breath gases were analysed and 3-day food records were collected to assess the nutrient intakes. The 63 MP were significantly olde r 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). The re were no differences in macronutrient intakes between MP and MNP. A posit ive 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 fibr e 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 adjusti ng for age. Dietary fibre intake was positively correlated with breath meth ane 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 enhan ce methanogenesis as MP become older and possibly pray a prebiotic role. (C ) 2000 Elsevier Science Inc.