If I brush my teeth in the morning and fast for 7 hours, my breath still smells kinda ok. But if I brush my teeth before bed then wake after 7 hours, it’s less pleasant. What’s happening to be different?

Question

If I brush my teeth in the morning and fast for 7 hours, my breath still smells kinda ok. But if I brush my teeth before bed then wake after 7 hours, it’s less pleasant. What’s happening to be different?

In: 6

Answer 1

While you sleep, you tend to keep your mouth open a bit. Instead of swallowing saliva to wash bacteria down to your stomach, you mouth tends to be more dry and the bacteria stick where they are and multiply. The bacteria are what smells.