Recent research data has shown that the major cause of bad breath is the tongue, not the teeth. Yes, be sure to brush and floss the teeth but then also clean the tongue. Look in the mirror at your tongue for some white stuff. This white stuff must be clean off in order to cure bad breath. Mints, gum, mouthwash, toothpaste, etc. will all cover up bad breath for a short time, however, they do not cure bad breath because they do not get rid of the bacteria on the tongue.

The food which gets stuck in the teeth is feasted upon by bacteria and that causes the smell

Stomach upset