Apparently the probotics come from the following bacteria families
"Streptococcus thermophilus and Lactobacillus delbrueckii subsp bulgaricus as well as Bifidobacterium and Lactobacillus strains that are added for their probiotic properties."
Personally, I would not want to knowingly imbibe strep in any form. These bacteria have to overcome the strong stomach acid, and also then fight off the immune system that responds to a bacteria invasion, so again, I feel it is like bull baiting. Most of the probiotic elements probably fall at the first fence and research studies have apparently found little trace in the duodenum or lower bowel to prove that they successfully got to their intended destination alive. Good marketing strategy, but not necessarily reflecting reality.