I have an interesting story that relates to this. When I was growing up, I had two close friends who lived down the street. Their mother was an extreme clean freak, always using anti-bacterial cleansers on everything all the time, constantly washing shit in the house. I never really made the connection until later, but my two friends were sick a LOT more than I was. They played outside (back in the good old days) with my brother and I all the time, but they would constantly get sick. I just thought they were unlucky, but later realized it might have well been due to their mother cleaning the shit out of everything.
definitely, sickness or illness and bacteria, viruses etc are like training for the immune system without anything to do naive t cells attack our bodies resulting in autoimmune illnesses. you see you have something called major histocompatibility complexes which along with antigen presenting cells(phagocytes, dendritic cells etc) allow you to self distinguish, with nothing to do this system sometimes fails and shit like allergies(immune system overeacting, and flus colds) happen as the immune system has no practice. allergies are premature or inappropriate degranulation of mast cells and improper production of key leukotrienes. if anyone has allergies they are one of the better illnesses that respond to natural intervention.
a cure for allergies, and colitis etc that has been proposed is self infection of parasites, and it works. there are studies on pubmed showing hookworm eliminates allergies, and they are now getting ready to introduce worms as a treatment for IBD.
so when you read these quack sites claiming everyone has allergies, just know that they are wrong. you would be very ill if you had a bad parasitic infection and they are obvious, with things like explosive loose stools and butt piss etc......
eat dirt, its good for you