Originally Posted by deirdra

I was just talking to the vet about this since my cat won't touch food with Fortiflora (daily dose forever w/IBD) on it, but likes Florentero (7-10 day dose, which comes from Italy but is cheaper in the long run and Dweezil needs to eat!). Both are human-grade probiotics.

Evidently there are different strains of Lactobacillus and Bifidobacterium and some set up robust colonies that sustain themselves whereas other strains aren't as robust and die off faster than they can reproduce, so the colony will die off if you don't constantly add more. These are cheaper per pill and of course the pharmaceutical companies want you as a customer for life, not for a week or 10 days. Both have similar numbers of bacteria per pill/tablet, but the strains (sub species level, not indicated on the labels) are different.

Originally Posted by deirdra

If you eat sugar and other SAD crap, you feed the bad bacteria which overtakes the good bacteria. In this case the colonizing dose wouldn't work if you're constantly killing off the good bacteria, like most people on the SADiet. So this is why most North American pills, yogurt etc. use the cheaper dose strains instead of the robust colonizers. Also, most EU countries have public health systems, so they promote short-term remedies.