[sudosysgen]

>This bright biological line conclusively does not exist.

It does. Bacteriophages cannot infect human cells. They can only do it by changing our microbiome.

>If this is your argument, then what is the default for removing something that is benignly present in the vast majority of people? Surely it should be that it is potentially unsafe, like it is with the appendix and gut microbiome and frontal lobe etc. Anyway this is a historical argument. We've applied huge amounts of pesticides because there was 'no evidence they were harmful.' It turns out this was a bad idea. This framework is clearly very dangerous. Perhaps we should look harder for evidence of harm before we do things.

EBV causes millions of cancers, and it seems that it is likely to cause millions of cases of autoimmune diseases. It is known to cause vast amounts of harm. By the same logic. Beyond this, a large proportion of viral infections of EBV cause mono, which in and of itself is a great harm. You can't ask that every future intervention prove a negative.

> In my experience, no one does this. And certainly never with the most important confouding varibables like diet and lifestyle.

Is your theory that for some diets and lifestyles, EBV has beneficial effects? You can certainly design a study to account for this.