I believe there is no valid evidence either way so far...the research that has been done just proves that you active bugs remain active in the gut...whether or not they do any good is still a mystery....but if you like it....I used to have one of the drinking ones daily but stopped when I realised how much sugar each one contained....didn’t see any difference in how i felt.
yoghurt is a good source of the same things as milk except in a more concentrated form. Some people may also find it more digestible than milk or cheese. Watch the commercial ones as they are often stuffed with sugar.
I wouldn't bother with Activia. Instead I'd have a good plain or Greek yogurt...no frills,and "live"...meaning it's naturally full of good bacteria which are necessary for gut health. The sugar in Activia isn't.
A 125g pot of activia contains about 16 grams of sugar. That over three teaspoonfuls. It's far from an ideal quantity of sugar and personally, I'd not tell your dentist you're eating the stuff.
With regard to the bugs, forget the benefits. There are no demonstrable peer-reviewed scientific papers that provide a favourable review of the benefits of these yoghurts. The only studies that are favourable have been sponsored by the manufacturers in one guise or another.
Taking bog-standard supermarket yoghurt is just as good for your health. Just select one with a low level of sugar.
Er, Many Thanks Pasta and Prof for yet more warnings - is there anything out there which is good and beneficial - yeah, I know, it depends on what I like, but....?
And remember......almost everything marked 'low fat' is loaded with sugar - I have full fat Greek yohurt because I like it, we need fat in our diet and it isn't loaded with sugar - have also made a point of eating local yoghurt or equivilant whenever I've travelled abroad and to date have never had any sort of digestive problems - and have been in some pretty remote places especially in Africa.