In 1969, a American, Levitt, has published a paper in New Engl J Med reporting that our coliform bacteria produced hydrogen every day, and that hydrogen accounted for 74% of the total gas produced by our coliform bacteria. Interestingly, in many people who live long lives, their gut bacteria are much more capable of producing hydrogen gas than the average person. Japanese scientists have found that the intestinal flora of centenarians is three times more capable of producing hydrogen than the general population.