I'd be very surprised if these experiments haven't been already performed either intentionally or unintentionally. As I pointed out before, germ-free mice with custom microbiomes are readily available but aren't significantly healthier (have less chronic disease) than non-germ-free mice.
Would you have any studies that you can link to which demonstrates this? When I did a quick Google, I could not find any.
If it's so hard to infect mice with the right pathogens as you seem to imply, that means pathogens are unlikely to be a significant cause of chronic diseases in mice.
Mice and rats living in their natural environment out in fields and streams will likely be exposed to a lot more pathogens than mice living in clean plastic boxes in a lab. Being in a plastic box mice run is like living in lockdown conditions, because they are not in contact with any other mice or animals which might spread infections by animal-to-animal contact.
In a lab, mice may pick up some infection from the humans caring for them, but in many cases, mice have their own version of each virus, and the human version does not infect mice, and vice versa. Human cytomegalovirus does not properly infect mice, and mouse cytomegalovirus does not properly infect humans, for example.
But in the unlikely event that that the right experiments haven't been performed, this also means that the pathogen theory currently lacks evidence for its correctness. So why should we led it more credence than more established theories?
What established scientific theories of chronic disease are there? There are very few actually. And theories that were once considered viable have now been struck off the list of possibilities.
20 years ago, it was thought that genes would explain nearly all chronic diseases, if only we were able to fullly sequence the human genome.
This belief that genes would underpin almost every disease was the driving motivation to get the human genome sequenced, which was finally achieved in 2003, at the cost of around $2 billion in today's money. The sequencing of the human genome was considered so important for the advancement of medical science, that President Clinton actually announced when this massive international project was complete.
But once we had all this genetic data to hand, it turned out that genes were not responsible for most chronic diseases. Which was a huge blow to the dreams of medical researchers, who wanted to understand the root cause of disease. Sure, genes may play a limited partial role in some diseases, and people with certain genes may be more predisposed to developing certain diseases; but that's about as far as it goes. We now know that genes are not the fundamental causal factor in most chronic disease (with a few notable exceptions like Huntington's disease, which is primarily genetic).
So we have to look for other fundamental causes of chronic diseases. And there are not many causes about: in terms of possible causes, you have only around 6 possible causes: genes, epigenetic factors, diet/lifestyle factors, conditions in the womb during gestation, environmental toxins (man-made and natural toxins, including radiation), and finally the pathogenic microorganisms living in a host.
That's all the causes that exist. Thus the causes of chronic disease must be found in that list. And we know we can cross out genetics, because that failed to provide the answers. And toxins are not that likely either, since chronic disease existed long before all the modern man-made chemical toxins we now find in our environment (though numerous studies show toxins do play a causal role in triggering chronic disease).
So when you do this detective work, and narrow it down to the feasible causal culprits, you see that there are very few culprits in the identity parade line up. And infectious pathogens, which are the oldest enemy of mankind, responsible for killing more humans than any other cause, is standing right there in the line up, with a murderous look on its face!
Edited by Hip, 15 May 2021 - 11:13 PM.