Is there such a thing as natural bad breath?

I’m wondering because ever time I kiss my girlfriend she says my breath dosnt smell verry good. I brush my teeth 3 times a day, I floss, and I use mouthwash.

Whats the best thing for bad breath?

I’d chew gum (mint) then spit it out then after about 30mins my breath would go bad is there a cure for this ?

What is the polite thing to do when someone has bad breath?

I work at a high dollar fine dining resturaunt. There is another young lady there who had horrible breath. This is such a problem that her guests have even complained to members of management. What do we do? I don’t want to hurt her feelings?