The caffeine in coffee can dry out your mouth by slowing saliva
production, which can lead to bad breath. A lack of saliva causes bad
breath for a couple of reasons.
One is that saliva helps kill bacteria found in your mouth, and the other is that saliva helps you digest food particles caught in your teeth and other areas of your mouth.
If there is no longer enough saliva in your mouth because of caffeine, then the bacteria that cause bad breath will grow out of control.
Similarly, if your mouth isn't producing enough saliva to digest the food particles caught in your teeth, bacteria will begin to break down those food particles, giving off bad odors in the process. Coffee is worse than usual in this regard because of its sulfurous content, which certain bad breath-causing bacteria can break down to produce odor.
One is that saliva helps kill bacteria found in your mouth, and the other is that saliva helps you digest food particles caught in your teeth and other areas of your mouth.
If there is no longer enough saliva in your mouth because of caffeine, then the bacteria that cause bad breath will grow out of control.
Similarly, if your mouth isn't producing enough saliva to digest the food particles caught in your teeth, bacteria will begin to break down those food particles, giving off bad odors in the process. Coffee is worse than usual in this regard because of its sulfurous content, which certain bad breath-causing bacteria can break down to produce odor.