Our ancestors were continually exposed to all kinds of infectious agents. Bacteria, viruses, dirt. You name it. There was no antibacterial hand lotion. No running water. No sani-wipes. Interestingly, as we have continued to live in a more and more sterile environment, under the mistaken idea that it is good for us, rates of atopic disorders like allergies and asthma have gone up. Why?
Our immune system needs to be trained. Just like our muscles it needs to be worked out. Especially as we are just starting out in this world as newborns and infants. The term is immunotolerance. The ability of our immune system to respond to what it is supposed to respond to and not respond to stuff it’s not (which also includes our own tissues).
Arguably the most critically time in our lives is up until about 2 years of age. After this point the immune system is a little more set in its ways. Thus, the exposure to healthy bacterial flora in the gut from vaginal birth, from nursing, from avoiding antibiotics to avoiding overuse of vaccination, contributes to the healthy development of our immune system. Also, I strongly promote the use of locally grown (must be local!!) honey to expose the developing immune system to local pollens, protecting against allergies much the same way pets do in this study. Of course, just to be safe, avoid the use of honey in infants under a year to avoid the low, but potential risk of botulism.
With all of these factors in mind, it should come as no surprise that this current study finds that exposure to cats or dogs in our first year of life cuts risk of being allergic to either dogs or cats by a whopping 50%. Interestingly, the protection was even greater (67% lower risk, if the child was born via C-section. Makes you want to go “Hmmm….”
http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2222.2011.03747.x/abstract