From the Manufacturer:
Children's Acidophilus is a high-potency, multiple species probiotic supplement. It provides beneficial bacteria in amounts that help establish an excellent digestive environment. Micro encapsulation helps to protect the cells against the destruction caused by the harsh acidic environment of the stomach. Without this, the vast majority of beneficial cells would be destroyed. Institute Rosell of Montreal, Canada, a world leader in probiotics, manufactures our Children's acidophilus through a proprietary process that ensures the survivability of the cells at room temperature; therefore, this product does not require refrigeration.