Picking French fries out of the waste basket....
What, you never did?
Bacteria are not motile. They depend on being physically picked up, through adherence to another surface or riding along with some other means of motility.
A definite part of your body weight is already bacteria, so a few more ingested or coming into contact with your body do not normally make that much difference. In fact most pathogens have direct antagonists from other species of bacteria, as well as antibodies created by the host on which they find themselves.
If it’s so harmful to eat food that’s fallen on the floor, then why isn’t there a 90% mortality rate for babies and toddlers?
Lots of bacteria are mobile.
Ever hear of an ameba?
Or a flagellum?