I would also add to the list of things that cause bad breath
11.) Poor oral hygiene
12.) Dehydration
13.) Constipation
14.) Diabetes in rare cases (bad breath is the smell of ketosis here - like bad apples)
15.) Liver problems in some rarer cases can lead to bad breath. This doesn't have to be serious liver problems. It could just be a sluggish liver, sluggish due to certain nutrient deficiencies or due to toxin overload.