Can gluten intollerance be acquired?
No. Rye, wheat, oats and barley all contain gluten. Some one who is gluten free may describe themselves as not being able to eat wheat for simplicity. However, there is a difference between a gluten intollerance and a wheat intollerance. If you are cooking for someone with this dietary requirement you should always confirm exactly what to avoid.
Pure rye flour does not contain any wheat. However, most commercial rye breads include a mixture of both rye and wheat flours. It is important to note that many persons on a wheat-free diet suffer from celiac disease, which is an intollerance to gluten, a sugar found in wheat and other grains. Since rye does contain gluten, it is not a suitable wheat-alternative for individuals on a gluten-free diet.
No Butterfingers are not gluten free. They contain corn flakes which contain gluten. Therefore they are not gluten free. Actually the corn flakes they use are gluten free http://www.specialtyproductsinc.net/ Butterfingers are listed by Nestle's gluten free candy list. Corn gluten is not believed to be a problem for people on gluten-free diets.