Of all Solgar probiotic supplements, this is the most active. This formula provides Lactobacillus acidophilus, Bifidobacterium lactis, Lactobacillus paracasei and Lactobacillus rhamnosus. Solgar Advanced Multi-Billion Dophilus is free from sugar, starch, yeast, wheat, soy, gluten and dairy products. Formulated without the use of artificial flavorings, preservatives or colorings. Suitable for vegans.