Hi and welcome to HCM
The main treatment of bad breath
coming from within the mouth is good oral hygiene
. Best way to lessen/ get rid of this is brush your tongue after brushing your teeth, make sure you get the back and all of the surface of your tongue, because food particles remaining in the taste buds
If you smoke, try to stop. Smoking increases the risk of developing gum disease
. Have regular dental checks at intervals recommended by your dentist
. A dentist can detect build-up of plaque and remove calculus. Early gum disease can be detected and treated to prevent it from getting worse.
Hope this will helps you. Take care.