Are you referring to
Dr Igor Markov's chronic bacterial intoxication syndrome (CBIS) theory of ME/CFS, where he postulates that ME/CFS is caused by bacterial toxins entering the systemic bloodstream from a bacterial dysbiosis in the kidney?
I find Dr Markov's CBIS theory very interesting, especially since he also says that treating the kidney bacterial dysbiosis leads to a permanent cure of ME/CFS. His own clinic claims a 93% success rate in permanently curing ME/CFS by using autovaccines to treat the kidney dysbiosis. Unfortunately treatment takes time, 2 to 3 years for patients to reach full remission. Though he says you should see improvements within the first year.
One of the reasons I find the CBIS theory of ME/CFS intriguing and plausible is that at present, medical science has very little ability to detect bacteria toxins in the blood. For the most well-known bacterial toxin, lipopolysaccharide (LPS), there are now commercial lab tests which can measure blood levels.
But LPS is just one out of hundreds of different very pernicious toxins that bacteria will synthesis and secrete, and we do not have much in the way of blood tests which can detect these many other toxins.
So basically, as far as I am aware, medical science has a major blind spot when it comes to detecting bacterial toxins in the blood. So these toxins may have been present in ME/CFS patients all the while, but we have not developed the right blood tests to detect them.
Dr Markov was able to detect high levels of bacterial toxins in the blood of ME/CFS patients using a unique bacterial toxin test developed in the Ukraine. He finds without exception, all ME/CFS patients have these toxins in their blood.
These toxins Markov finds could be one in the same as the "
something in the serum" that various ME/CFS researchers (Fluge & Mella, Ron Davis, Bhupesh Prusty) have found in ME/CFS blood, that negatively effects healthy cells in vitro, when those cells are exposed to a drop of ME/CFS patients' blood.