Microorganisms yes, but what kind and their activity? In this matter some advertisement and producers seem to not be extremely worried about indicating what kind of bifidus we are talking about. "Bifidobacterium" are usually presented as "intestinal bacteria" although in there are more than a few categories of them. Some sources cite one thousand, others less or more but for sure the magnitude is high.
The price is higher than the usual milk byproducts of this category, so the user should be informed about what kind of bacteria appears and the specific benefits for health, or perhaps this is another case of a technique to increase the price with a non ethical background. There are regulations about products that claim health benefits but to include "bifidobacterium" isn't exactly this. Furthermore, the package usually forgets to specify what these microorganisms are doing.
Bifidobacterium animalis, a possible bacteria for being present in the milk has some documented effects in spool frequency or greater score in questionnaires about quality of life. Probiotics is an idea based in substitute some bacteria for others to achieve a different performance, claimed to be better for health.