Probiotics are living microflora that play a critical role in maintaining good health by supporting normal bowel function and a healthy immune system. Primal Defense Kids contains a 4 billion live cell count of four species of beneficial probiotic cultures. It contains a unique Bifidobacterium blend with the probiotic Saccharomyces boulardii, that supports healthy intestinal epithelium lining integrity, the front line for the body's defense system. Its three species of Bifidobacteria: Bifidobacterium breve, Bifidobacterium infantis and Bifidobacterium longum, are all found in a healthy child's digestive tract and have all been clinically studied in children, as has Saccharomyces boulardii. Primal Defense Kids is made with organic banana so your child will enjoy taking it. It can be used effectively and safely by children aged three years and older.