I've asked a friend of mine that works in a science department, and he says that the penicillin and all the other antibiotics
that are used
in everyday cow, chicken, etc consumption CAN linger in the foods we eat.
For most of us, this can cause bloating, gas, constipation/diarrhea, heartburn, etc.
Even though I can die from certain antibiotics, I ONLY suffer those ( and other ) symptoms after eating meat. Guess it's pretty diluted once cooked?
I've seen a few documentaries based on this...