It is mentioned on the JoS website as well but they forget to tell some important things..
You have gut bacteria. Those bacteria are part of the immune system. They are valuable in aiding the digesting of food, for some produce or free certain vitamins that we need (since that stuff is vital to us)...
.... Oh and by the way, not all bad organisms are anaerobic.. There are some that are aerobic. And there are some 'bad' bacteria/fungus that are aerobic.
So since it might have many plus sides it is not safe to take without something like probiotics, especially if you use it longer term.

