Wow, blast from the past! Thanks for keeping me in mind Ken.
I hope and assume that not hearing from you in so long is a good thing and that you and your wife are doing well?
NAPAY wrote:So, I ran into this. Seems to me this is what you're talking about?
I think the right answer is "yes...in part".
The digestive tract, from all I've read, is really like our outside turned in (that's the term most often used
) in that when considering interaction with the immune system, the digestive tract is "external" and the effects of those gut bacteria, while essential to our continued well being, for the purposes of our immune system are "external" and don't directly interact with our immune system.
That said, you're absolutely right to take the idea that you have and it's not entirely wrong. Hygiene hypothesis researchers and admittedly I use intestinal flora to prove that "ME" isn't REALLY just that single, completely independant organism that we are most comfortable believing that we are.
Although misleading, the value of the comparison is that it's considered that humans originally were self sustaining and able to convert/create the necessary vitamins and minerals on our own. In time, due to the ongoing and unavoidable presence of gut bacteria doing the same job for us, we partially lost the ability. Not to humanize Mother Nature but redundancy has an unfavorable cost/benefit ratio and is evolved out. In the above situation maybe a better way of putting it is that even though intestinal bacteria isn't "US", it seems they won the job of processing our stomach contents and in the time since we've lost the ability to do it ourselves.
With the above in mind, "internal" parasites which do live within the jurisdiction of the human immune system have (like intestinal bacteria) been an ongoing and unavoidable factor throughout human evolution. Considering that a large part of the "duty" of the immune system is to eliminate or isolate foreign invaders, it's obviously contrary to the purpose of the human immune system that foreign organisms almost the size of a finger are able to comfortably survive in us. It seems to defy logic that the immune system is easily capable of eliminating them, yet doesn't.
To shorten things.....from the beginning it's been noticed that the alarming rise in autoimmune/inflammatory diseases align with people moving from the farms to the city for the "Industrial Revolution" and those economies changing from self sustenance and bartering to currency based and the result was that those same populations are now considered "developed" in that they have electricity and the modern conveniences that brings.
Interestingly, helminth parasites and parasites in general are, like cockroaches and rats, are masters of adapting to survive. Despite that, for the first time in the history of humanity the living conditions we now define as "developed" were such that the specific helminths which had shared our bodies through evolution were no longer able to complete their life cycle and died off. Yes, their eggs remain infective in the soil for many years but that time is long past and contrary to articles about the benefits of eating dirt, the soil in developed countries is sterile in that regard.
When it comes to the hygiene hypothesis or loss of evolutionary normal conditions why does it seem that everyone is "hug up" on helminth parasites when there are lots of other types of parasites (partial list http://en.wikipedia.org/wiki/List_of_pa ... _of_humans
) seems almost exlusively owed to the fact that it takes a much bigger garage to "protect" the Goodyear blimp than to "protect" a Smart car.
Helminths are far and away the biggest of the human parasites and in order to continue surviving had to employ completely different methods than bacteria, viruses, etc... which are small enough to hide from the immune system in our cells and replicating faster than the immune system can eliminate them, whereas the helminths can't hide and have had to take our immune system head on. Not a lot is known about it but there is no other way to explain the comfortable survival of helminths in humans other than their controlling aspects of our immune system.
Cutting it short, it's unquestioned that our well being hinges on the balance of our intestinal flora, which doesn't even interact with our immune system.
Expanding on that thought, what repercussions might we expect from the loss of the helminths which logically were controlling aspects of our immune system in which the human system lost the ability to control eons ago....A host of immune problems,,,in the places times and populations that the alarming rise in autoimmune diseases were first noticed?
Combine the documented effect of adding helminths in people with immune problems and the first thing to come to my mind is why would the existence of parasites have ANY effect on inflammation and autoimmunity otherwise?
No doubt, LOTS needs to be determined-proven but I find it pretty interesting.
Hopefully that seems to make some sense?