fyi, House is a medical drama on tv. I'm assuming they have real doctors on the writing staff so this info could be accurate and relevant. Last week's episode, this patient had a couple of symptoms we have. No mention of bad breath but here are the parts that might interest you:
"her lack of spit makes her mouth a breeding ground for a fungus like candida... it wiped out her mouth's immune system.. that's an opportunistic infection, not the underlying condition".
That's the best diagnostic i've heard, from a real or fictionnal doctor

It turned out it was an asthma inhaler that was causing some of those symptoms. What i learned from that is the bacteria, the fungus, the bb aren't what we should be focusing on, we need to find our underlying condition that's messing up our mouth's immune system and allowing bacteria to breed. Fighting symptoms is a lost cause.