Very interesting speculation of yours, Emootje, that in chronic fatigue syndrome,
hydrogen sulfide (H2S) may not come from the gut, but rather come from inflammation, and/or from coxsackievirus B infection in the body.
Also very interesting is your observation that, in spite of high H2S readings on the De Meirleir Neurotoxic Metabolite Test, often people with CFS produce no H2S smell in their farts; and moreover, that other healthy people without CFS can have very odorous H2S farts.
I had a very high reading for H2S on the Neurotoxic Metabolite Test, but my farts are almost always odorless (this usually means they are mainly methane, which is a gas that has no smell).
Not only that, but also I notice on the rare occasions when, due to the food I have eaten, I do produce some H2S farts, during these times I generally feel
better, not worse, as a result of the H2S being produced in my guts. My whole digestion seems better when I produce H2S flatus, in fact.
In my case, it seems like H2S in my flatus improves my CFS symptoms.
So what is going on here?
One possible answer is the following.
It is known that increased levels of H2S in the colon causes the colon mucosa to secrete more
H2S detoxification enzymes, which neutralize H2S by converting it to thiosulfate. Colonic mucosa tissues possess a specialized detoxification system for this H2S detoxification (references
here and
here). Other non-colonic tissues are much less efficient at neutralizing H2S.
So, could it be that, when H2S is produced at high levels in the gut (by bacteria digesting food), the detoxification enzymes then produced by the colon mucosa serve not only to neutralize H2S in the gut, but these enzymes may go on working to generally lower H2S in the body as a whole?
This may be why I often feel better, not worse, when I have H2S in my flatus.
Assuming that H2S is a cause of CFS, then it follows from this that perhaps people with CFS should be eating the right foods to
increase H2S production in the guts, in order to increase the production of the H2S detoxification enzymes generated in the colonic mucosa. At least this would be an interesting experiment.
Another possibly might be to take these H2S detoxification enzymes as a supplement (if they were available in future, and safe); or try take herbs or supplements that might increase the natural production of these H2S detoxification enzymes in the body.
From what I have discovered, one major H2S detoxification enzyme is
thiosulfate sulfurtransferase (TST), which is a component part of the enzyme
rhodanese (reference
here). I am not sure if this is the only H2S detoxification enzyme generated in the colonic mucosa, or whether there are other H2S detoxification enzymes also generated.
Incidentally, hydrogen sulfide in the gut seems to be
involved in ulcerative colitis too.