The reason we floss is to get bacteria out from between our gums and teeth. Bacteria can be very smelly. Make sure you floss everyday and you wont have that problem as much.
Why Does It Smell When You Floss?
Dental Floss reaches the areas a tooth brush can't reach. If you don’t floss you’re not cleaning food debris & bacterial dental plaque off all the surfaces of your teeth - It’s as simple as that.