During Mass, if you swipe your tongue around your mouth and you find some little bits from an earlier meal stuck in your teeth or anywhere around your mouth, then swallow it, does that break the fast before Communion? Thank you!
The moment we receive food into the mouth, the process of digestion begins with enzymes in our saliva. Just swallow it if it comes lose. Whatever remnant of food from a previous meal remaining between teeth will not break the fast. To fast is to refrain from accepting any NEW food into the mouth.