Coffee can induce foul breath owing to its strong flavor and the influence it has on saliva production. Caffeine reduces saliva production after drinking coffee. Less saliva equals more odor-causing germs. Other substances in coffee that can cause bad breath include acetaldehyde and phenols. The more you drink coffee, the more likely you are to develop bad breath. This is because caffeine reduces salivation, which helps remove bacteria-rich food particles from your tongue to prevent tooth decay and gum disease. If you suffer from chronic mouth odors, stop drinking coffee because it will only make them worse. If you're worried about how coffee affects your breath, try not to drink too much of it or for too long a period. The same goes for tea; although it doesn't have any caffeine itself, the amount of sugar it contains can also lead to excess acidity in your body and promote bacterial growth if you drink too much over time. Bad breath may be caused by other factors as well. For example, if you have diabetes and don't take care of yourself by checking your blood glucose levels or visiting your dentist regularly, this could also contribute to developing bad breath. In conclusion, yes, coffee can cause bad breath.