Under the labelling guidelines, only a few organisms can be called probiotic. In our kefir, these are the acidophilus (= Lactobacillus johnsonii) and Bifidus bacteria. Some dairies count all the live organisms and arrive at astronomical numbers. The number of live probiotic organisms goes down over the course of the shelf life because the ongoing fermentation causes the pH level in the kefir to drop. Bacteria are quite sensitive to a low ph environment.
