Culturelle Health & Wellness Immunity Support Formula contains 15 Billion active cultures of 100% Lactobacillus GG, the most clinically studied probiotic strain. That’s a clinical strength serving or amount of probiotic in every capsule. When taken every day, Culturelle supports your natural defenses for stronger core health. Culturelle Health & Wellness safely and naturally restores the balance of good and non-beneficial bacteria in your digestive tract, where 70% of the body’s immune system resides. Balancing this bacteria not only gives your whole immune system a tune up and supports your natural defenses, but also helps your digestive system work better.