Methanogens versus the sulfate-reducers in the colon

1993: Role of dietary sulphate in the regulation of methanogenesis in the human large intestine
Christl SU, Gibson GR, Cummings JH
MRC Dunn Clinical Nutrition Centre, Cambridge

1994: Methanogens outcompete sulphate reducing bacteria for H2 in the human colon
Strocchi A, Furne J, Ellis C, Levitt MD.
Minneapolis VA Medical Center, MN 55417

It's not known if the methanogen/sulfate reducing 'war' would have any significance in a body odor problem such as fecal body odor. Some feel they can smell of rotten egg, especially after eating high sulfur food, which makes you wonder if they are obvious 'sulfate-reducer dominant' (sulfide-producing dominant) in their colon (the sulfate/sulfur being changed to hydrogen sulfide by the sulfate reducing bacteria).

The current thinking is that either methanogens or sulfate-reducing bacteria are present in the colon. People are either dominant in one or the other. They are supposedly incompatible. Both compete for available hydrogen. Two well known departments in mainstream medicine are those run by MD Levitt in Minneapolis USA, and that by Glenn Gibson in the UK (now at Reading University). Both depts seem to have come to the conclusion that both bacteria compete and that people are dominant either in one or the other.

It would be interesting if a study was ever done regarding this and fecal body odor. Perhaps all would be 'sulfate-reducing bacteria dominant', since rotten egg seems to be a common smell. Methane is seemingly odorless. A skim-read of google searches on methane suggest it may be the reason that some can do 'flame-thrower' farts (using a lighter). It is not recommended trying this at home!

Checking for methane in the 'small intestine bacteria overgrowth' breath test was added probably because of such research as above. This breath test check for hydrogen levels, but they now know that methanogens use up hydrogen too. So they wanted to make sure the lack of hydrogen was not caused by methanogens 'eating' all the hydrogen.

You would think it may be wise to add sulfide in their breath tests, since these seem to consume hydrogen as well. Sulfate reducing bacteria produce sulfide. Perhaps it may even turnout that someday methanogenic bacteria are a good probiotic, although there has been some negative research on methanogens (e.g. one paper where methanogens were associated with constipation). Currently it is not known what significance methanogens or sulfide-producing play in the colon.

---

Related links:
About the small intestine hydrogen breath test