Give me a clue about skim milk, soy, probiotics, etc., etc.

[Major Nikon]

12. Activia contains a particular set of probiotics

This really just refers to which strains of beneficial bacteria they are using. Some reportedly have more benefits than others. I'm not sure how much of this is based on real science and how much is based on hype. Almost certainly much of it is unproven pseudo-science. What probiotics will do is keep your lower digestive tract clear of unwanted bacteria and they also have the potential to bind with certain compounds believed to be carcinogenic and render those compounds harmless or at least move them out of your system. There may also be other benefits such as helping with symptoms for people who have constipation as a result of IBS.