Culturelle Immune Defense Chewables help keep your immune system going strong all day long*. Four (4) powerful ingredients are packed into a once daily super immunity chewable. Culturelle Immune Defense Chewables are powered by 10 billion CFU's of Lactobacillus rhamnosus GG probiotic. Over 1,000 scientific studies and 30 years of research have demonstrated the safety and efficacy of this probiotic strain. In addition to Lactobacillus rhamnosus GG strain, the super immunity chewables contain an excellent source of Vitamin C, Vitamin D and Zinc and are made from naturally-sourced Elderberry fruit juice, an ancient superfood.