Vickie Tyree wrote:
>>The immune system resides in the gut.

This is not true. I realize that you can find the statement in many places on 
the internet, usually in conjunction with "leaky gut syndrome," but most of 
the places you find it turn out to be selling digestive enzymes or supplements 
or herbs or even weirder stuff. They can't even agree on their pseudoscience. 
Google "leaky gut syndrome" and you see statements that "70% of the immune 
system resides in the gut" or 50% or 60% or part of the "adaptive immune system" 
or "direct immune system" or other variations.

Leaky gut syndrome is not really recognized by the mainstream science 
community. It is part of alternative medicine, but because it has no recognized 
existence alternative practitioners are free to invent any set of symptoms and 
cures they want to sell. Since all cures will be anecdotal, and many will simply 
involve taking an offending food out of the diet anyway, the cures might lead 
to an alleviation of symptoms for some. 

How Stuff Works has a good, plain-language explanation of the immune system.
http://www.howstuffworks.com/immune-system.htm

Another straightforward set of pages are those on Allergic Reaction at 
eMedicinehealth.com
http://www.emedicinehealth.com/allergic_reaction/article_em.htm