I use a probiotic that contains 50 billion bacteria,and it is used in some hospitals here in Canada.
It is called Bio-K+Cl1285. I personnaly use the fermented milk formula which has the constancy of a liquid yogurt, but i know they also make it in capsules. But i find it hard to swallow, so the liquid form is more interesting to me.
I have been told that it is the most concentrated and efficient product there is on the market at the moment.