"So far, only three microbes have been identified as methane producers (methanogens) in humans: Methaniobrevibacter smithii, Methanospaera stadmagnae and Methannobrevibacter oralis.
Furthermore if you delve deeply into this subject as I have you start to see that in all likelihood the ability to produce combustible farts is probably genetic.
I am proud to say that I am in that proud minority of people who can and have lit their farts. Furthermore I need very little provocation to do so.
So where are we at as a species? Is this something that should be included on the genetic screens we do for our children and potential mates? "I can't date you until we go to taco bell and pick up some bic lighters. Its just how it is". Personally I'd prefer a mate with flamable flatulence in case we did want to procreate. I think any man worth his salt would want kids who could light their farts. Can you imagine the shame being the only one in the treehouse who can't burn farts as Frank Zappa put it? I woldn't want to be that kid.