Actually talking all the humanbeings are badbreathres. Oral cavity contains millions of anaerobic bacteria like fusobacterium and actinomyces which acts on the protein of food materials as well as putrifies them. This particular course of action leads to the formation of offenssive gases like hydrogen sulphide,methyl mescaptan,cadaverin,skatol,putrescine etc causing bad odor. If oral hygiene isn't maintained properly all will suffer from bad breath. Most of us control this by frequent brushing,tongue cleaning and gargling. Even after maintining cleanliness in the jaws some people suffer from offenssive smell due to a variety of causes which has to be diagnosed as well as cared for properly.
Some typical reasons for bad breath.

1) Poor dental hygiene:
If dental hygiene isn't maintained properly the mouth gets the seat for millions of bacteria which generate offenssive gases by degrading the food debris. Bad breath is severe in people who don't brush the teeth of theirs regularly and clean their mouth after every food. Snacks taken between meals also can take bad breath due to improper cleaning.
Badbreath is typical in nearly all people in the early morning on waking. During rest there's much less production of saliva.Saliva seems to have some antibacterial properties which help you to maintain the mouth clean. Saliva conains oxygen molecules which is called for prodentim better business bureau (https://www.kitsapdailynews.com/) to make dental cavity cardiovascular. And so the reduction in it's amount during sleep tends to make a favourable state for anaerobic bacteria.

2) Food habits:
The principle cause of poor smell is a result of degradation of protein by the bacteria and therefore just about all food products loaded with protein favours bad breath. Meat,fish,milk products, etc and eggs,cakes,nuts,pear is able to cause bad breath. Some food articles can produce certain type of smell which could be unpleasent. Raw onion can produce normal bad smell. It's said that an apple one day keeps a doctor away,a raw onion a day keeps everybody away. Eating groundnuts also can take bad smell. However if good cleaning is done smell can be reduced regardless of the dynamics of food. Irregularity in timing of meals can also produce bad breath. Little meal articles taken between the meals can also produce bad smell.

3) Biofilm:
There's formation of a thin sticky coating known as biofilm on oral mucosa as well as the tongue. This particular coating is thick on the posterior aspect of the tongue where millions of gram damaging bacteriae are noticed.The heavy coating on the tongue is definitely linked with badbreath. Even a thin biofilm is able to create anaerobic state favourable for bacterial proliferation.