But is it really so simple? Flood the body with preferential bacteria and they will be stronger than the other bacteria and kill them and replace them. I had a terrific holistic dr that had me taking probiotics 20 years ago. I took them for a few years, eventually came to the conclusion that I was throwing money away, or the value was something you would never notice. Quitting grains seemed to work better for my health than any other thing I've ever done.