Hi Rich,
I am pleased to see that you have begun to mention hydrogen sulfide in your posts. It is satisfying to see that my conceptual model demonstrating the potential connection between hydrogen sulfide and CFS is becoming accepted by prominent scientists. When I wrote my hypothesis, I was told that it could take thirty years before my ideas would be understood by the medical community, but already I can see aspects of my work being tested in a number of places. As I noted in my poster at the last IACFS/ME conference, dairy actually produces hydrogen sulfide, as do wine, sugar, and eggs, to name a few. Yeast and mold produce also H2S. And the story continues, from bacteria to the mitochondria. Perhaps we have the makings of a unifying theory, in that it potentially has the ability to explain so many of the findings in CFS (even glutathione depletion through the transsulfuration pathway!).
One thing puzzled me in your post. Dr. DeMeirleir appears to have embraced my theory as though it was his own, but has he actually demonstrated the production of H2S as an important mechanism in CFS? He said at the 2009 ME/CFS London conference that the results of his H2S tests shown on his slides would be published shortly thereafter, but I have not seen such a publication. Do you (or anyone else reading this blog) know where I can find it? I think it is important that all test results which underlie public statements be published and subjected to critical scrutiny of peer review and random trials if we are to make meaningful medical progress.
All the best,
Marian Lemle
Hi, Marian.
Yes, your H2S thinking seems to be catching on, at least among the "cognoscenti"

-), and it may be the key to linking Dr. de Meirleir's observations and emphasis on the gut issues to my GD-MCB hypothesis. Before you get too excited, though, be aware that neither Dr. de Meirleir's nor my ideas are very widely accepted within the "orthodox" CFS research community. We still have a major uphill fight ahead of us. What's going on in Belgium vis-a-vis the governmental response to CFS treatment is particularly troubling, I think, and I hope it doesn't cause problems for Dr. de Meirleir.
It seems to me that the mechanism Prof. Deth described could contribute to glutathione depletion, because cysteine is
usually the rate-limiting amino acid for the synthesis of glutathione, and about half the cysteine needed
by the human organis has been reported to come directly from the diet, the other half being produced from methionine
that also comes from the diet, via the methylation cycle and the transsulfuration pathway. Inhibition of cysteine absorption by the
gut via the mechanism he described would seem to impact glutathione synthesis strongly, and this may be one of the
initiators that can deplete glutathione and contribute to bringing about onset of CFS in some cases.
Initially, I had thought that the hydrogen sulfide produced in the gut came exclusively from sulfate-reducing
bacteria. However, I now understand that this is not correct. Sulfate-reducing bacteria are found in
the human gut, but perhaps most of the hydrogen sulfide produced in many cases comes from bacteria that
ferment other sulfur-containing species, such as cysteine. This would be a two-edged sword. Not only would
it produce hydrogen sulfide, which can overwhelm the sulfide oxidase in the cells lining the gut in high enough
quantities, and thus enter the blood and produce deleterious effects in the cells of the body, but also it would deny the cysteine supply to
the body, thus depleting the critical substance needed to make glutathione.
It seems to me also that this mechanism could contribute to a rise in the population of dysbiotic bacteria in the
gut that are capable of producing hydrogen sulfide from cysteine, which would tie in with your thinking and
Dr. de Meirleir's observations. Note from the abstract below that at least one type of Streptococcus can produce
hydrogen sulfide from cysteine. Dr. de Meirleir has emphasized the importance of both Streptococcus and
enterococcal bacteria in CFS.
Maybe this is a possible link between the pathogenesis mechanisms that Dr. de Meirleir has discussed, based in part on your thinking recently, and focused for a long time in the past on the gut issues, and the glutathione depletion--methylation cycle block mechanism that I have proposed. He and I have been at odds, in a friendly way, for several years over this difference between his emphasis on the gut issues, and my emphasis on glutathione depletion and the partial methylation cycle block. Maybe this will pull things together.
As far as I know, Dr. de Meirleir has not gotten a paper out about H2S yet, but as far as I know, he still plans to do so. As you may know, he is a very busy guy! Note that he is also emphasizing the role of D-lactate in the pathophysiology of CFS, produced also by dysbiotic bacteria in the gut.
It IS nice to see some of these things coming together.
Best regards,
Rich
J Periodontol. 2009 Nov;80(11):1845-51.
Hydrogen sulfide production from cysteine and homocysteine by periodontal and oral bacteria.
Yoshida A, Yoshimura M, Ohara N, Yoshimura S, Nagashima S, Takehara T, Nakayama K.
Division of Community Oral Health Science, Department of Health Promotion, Kyushu Dental College, Kitakyushu, Japan.
akihiro@kyu-dent.ac.jp
Abstract
BACKGROUND: Hydrogen sulfide is one of the predominant volatile sulfur compounds (VSCs) produced by oral bacteria. This study developed and evaluated a system for detecting hydrogen sulfide production by oral bacteria.
METHODS: L-methionine-alpha-deamino-gamma-mercaptomethane-lyase (METase) and beta carbon-sulfur (beta C-S) lyase were used to degrade homocysteine and cysteine, respectively, to produce hydrogen sulfide. Enzymatic reactions resulting in hydrogen sulfide production were assayed by reaction with bismuth trichloride, which forms a black precipitate when mixed with hydrogen sulfide. The enzymatic activities of various oral bacteria that result in hydrogen sulfide production and the capacity of bacteria from periodontal sites to form hydrogen sulfide in reaction mixtures containing L-cysteine or DL-homocysteine were assayed.
RESULTS: With L-cysteine as the substrate, Streptococcus anginosus FW73 produced the most hydrogen sulfide, whereas Porphyromonas gingivalis American Type Culture Collection (ATCC) 33277 and W83 and Fusobacterium nucleatum ATCC 10953 produced approximately 35% of the amount produced by the P. gingivalis strains. Finally, the hydrogen sulfide found in subgingival plaque was analyzed. Using bismuth trichloride, the hydrogen sulfide produced by oral bacteria was visually detectable as a black precipitate.
CONCLUSIONS: Hydrogen sulfide production by oral bacteria was easily analyzed using bismuth trichloride. However, further innovation is required for practical use.
PMID: 19905954 [PubMed - indexed for MEDLINE]