Culturelle Probiotics Ultimate Strength Daily Probiotic Capsules contain double the number of live active cultures of Lactobacillus rhamnosus GG, the most clinically studied probiotic strain† for clinical strength immune support.* These extra strength digestive support capsules safely and naturally restore the balance of good bacteria in your digestive tract, where 70% of the body's immune system resides.* Balancing this bacteria not only promotes a strong and healthy gut, but it also helps your digestive system work better and helps reduce occasional gas, bloating, and diarrhea.*