I'm really surprised you haven't gotten a response to this directly from the folks at Ganeden-Biotech (makers of DA-IBS). When I mentioned in another thread that I had run out of DA-IBS and was substituting Culturelle until I could get more, I got an almost immediate PM from the president of the company telling me what a mistake I was making. According to him, the difference is in the strain of lactobacillus. He says DA-IBS has a much more aggressive and effective strain. I'm sure they would be happy to answer any and all questions you have. Marty