Dear Ms. Scientist,
Why do we have morning breath even though we brush our teeth right before going to bed? And why is our breath not as bad at the end of the day right before brushing our teeth?
Even though our mouths may be exposed to more bacteria during the day due to the foods we eat, especially those high in sugar such as soda or candy, we produce more saliva that helps wash away the bacteria which is attracted to all the food residue left on our teeth and this keeps our normal microbiota in check.
Saliva also has enzymes and proteins such as lysozymes and immunoglobulin A (a.k.a. antibodies) that help kill bacteria and maintain a balanced microbiota. When we sleep, our mouths naturally dry out, allowing bacteria to flourish and create the not-so-good morning stench for others to experience.
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