BEST DENTIST IN CHOOLAIMEDU! Snoring is a major contributor to bad breath. Breathing through your mouth rather than your nose can dry out your mouth. By now you know that a dry mouth equals bad breath. The main reason for bad breath is the loss of moisture from the mouth when we sleep. It especially occurs when we sleep with our mouth open. When we sleep, the production rate of saliva inside our mouth decreases. People who snore due to open mouth, experience this saliva loss at a more severe rate. Saliva acts as a natural antibiotic. So, bacteria can’t grow in saliva. When we experience extreme loss of saliva during sleeping, bacteria flourishes. As a result, bad breath occurs.