Gum disease can contribute to bad breath. If you do not take really good care of your teeth and see your dentist regularly for dental cleanings, you may have a chronic bacterial infection in your gums. Do your gums bleed easily? Do they look red or puffy? Here is a test you can conduct: Use dental floss between your teeth (especially the back teeth) and then smell the floss. Sometimes the resident bugs smell really bad, which can give you bad breath. See your dentist, floss and brush and scrape your tongue.