I have also badbreath and it's came from my stomach a lot of people even a dentist said that it's impossible to have badbreath from the stomach, but then they can't give me a solution. I tried everything in this world from toothpaste to diet that did not work.
Now I read an article about low stomach acid can cause badbreath, and here's what the solution for low stomach acid, take betaine hcl and I add activated charcoal and presto in just few hour i feel a change in my badbreath, I don't know how but it's works and nothing will lost if you try. please just try I feel your pain I lost my job too because of this badbreath, i dont have a lot of friend.