What causes morning breath?
Your saliva acts as a natural mouthwash but when you are asleep, production in your mouth decreases. Bacteria found on teeth in the crevices and on the taste buds of the tongue, break down the food particles, which produce sulfur compounds. It is actually these sulfur compounds which give our breath a bad odor.
Chronic, long-term mouth odor can be a sign of more serious illness. See your dentist if this is a concern.