There have been many discussions of VSL #3 here, and a simple site search would provide you with tons of information. In my browser a magnifying glass icon is where Search lives.
I use a maximal dose of VSL #3 DS (4 packets/day), and I’m convinced that it helps keep my chronic pouchitis at bay. I was able to persuade my insurance company to cover the prescription-only DS (double strength) formulation.