Kefir and kombucha

It is a live food and it can kill yeast by rebalancing your body's flora. As the yeast die, they can release toxins. You don't want to release more toxins than you can excrete.

I think that kefir is different fomr kombucha in that it won't pull mercury out of your fillings.

Kombucha is the only ferment I know of that can mobilize toxins. Any can start changing your gut flora, and for some people that can involve die-off, but kombucha seems to work in a separate, additional manner.