Dietary Supplement. Clinically studied daily formula with 25 billion active cultures. Replenishes beneficial bacteria important for optimal digestive and immune health.*. Provides 2000 IU of vitamin D-3 for colon health.* 25 Billion CFUs. What are Probiotics? Probiotics work to keep a healthy balance of intestinal flora. They reduce the amount of harmful bacteria by replenishing and maintaining the "friendly" bacteria.* The depletion of beneficial bacteria can occur as a result of poor diet, taking certain antibiotics, stress, food poisoning, travelers diarrhea or poor overall digestive health.