The development of methane production in childhood and adolescence.

Methane concentration in the expired air was analyzed in 393 infants, children, and adolescents. There was no methane production below the age of 3 years. In the age group 3-4 years, 6.4% of the children produced methane. The percentages were 14.3-18.2% in children aged 7-14. A rise in methane production to 39.4-45.9% was recorded from age 14 to 18, as compared with 49.4% in adults in Israel. The reasons for these changes in methane production with age are not known. Alterations in the colonic flora or the production of a specific substrate(s) are the main possibilities. In our opinion, the latter possibility deserves further investigation.