Dick, One of the problems with acidophilus is, it is based in dairy,(not allowed on neanderthin and dairy is a very common allergen) or it is based in maltodextrin, a starch or sugar. So, by taking acidophilus, aren't you giving nourishment to candida albicans, clostridia (bad bacteria)?? Wouldn't it be better to take nothing and simply starve out the candida albicans/bad bacteria, rather than chance feeding them the maltodextrin/dairy products??? If you stay strict paleo, you are not providing them much nourishment, esp if you cut out fruit, which I have done. I eat meat, fish, veggies,nuts--no starches or sugars. Also, Ray mentioned every day we are taking in bacteria on food that we eat anyway, you don't need to take additional acidophilus. Just being the devil's advocate, anyone prefer to respond? Not a flame. This is an issue I struggle with for my son---to be or not to be?? That is, to try and supplement the good bacteria, or leave well enough alone and go paleo? Right now, we are doing the latter.