Stop bad breath. It often has reversible causes.
There is a lot of emphasis on dental hygiene in those suffering with bad breath. Of course, those with rotten teeth will have bad breath, but in the modern world and good dental care that's actually pretty rare. So we have to look elsewhere, where good dental hygiene and regular tooth brushing aren't relevant. That's the throat, as the air we breathe out passes through this area just like the mouth. In particular the tonsils, which are difficult to clean and clear, yet often contain deep crevices and holes where food can trap and decay. These holes and crevices can usually be removed by laser vapourisation under local anaesthetic spray, a lunchtime procedure.