parasites are almost evrywhere (its true, check it out). just because someone eats a parasite doesnt mean they are going to be definitely effected. if conditions are right parasites become a problem, but thats not everytime. If your body is weak you are more prone to diseases. Not every one died from the black plague. But just like humans if you introduced to certain things in small quanities at a young age you are less prone to fall prey to them later. Thats adapting. so it is a good idea to introduce different things to your frog and start at a young age. You should NOT do this if your frog is old and has never had it before in its life. that may be a higher risk.