But isn't it already known that even personality characteristics can sometimes be passed along with fecal transplants? I remember a recent article regarding this in Clinical Psychopharmacology and Neuroscience. Likewise there appear to be obesity linked and thinness linked microbiomes which are at least sometimes transmissible deliberately.
Further, there is no good reason it should be impossible for doctors to deliberately transmit cancer from one individual, or even a cancer lab culture, to a previously nondiseased individual. Historically, HIV has been deliberately infected by physicians, so why not cancer. I personally have miraculously escaped HIVi nfection from several deliberate physician attempts, although I haven't been tested since the last possible iatrogenic exposure at the beginning of this year, involving a 4 day period during which the virus could have been deliberately introduced by concomitant IV along with steroids.
Human beings, including doctors, are capable of horrors. There is no doubt in my mind that certain cancers lacking other explanation are frequently deliberately introduced by doctors. No doubt men have been deliberately infected with normally exclusively female cancers and vice versa. Such trust as I may once have had of doctors is long gone. I've had them try to kill me too many times. If you wish to call me paranoid, talk to the FBI about it. Doctors can be very bad; psychiatrists are generally very worse.