Does Flora Bloom need to be refrigerated ? How is it treated?

The probiotics don't need to be refrigerated because it's "freeze-dried", freeze-drying helps protect probiotics viability. Also, they used a technique called "Microencapsulation", this is a process in which tiny particles or droplets are surrounded by a coating to give small capsules, of many useful properties. In general, it is used to incorporate food ingredients, enzymes, cells or other materials on a micrometric scale. 

Storing in a cool, dry place is a standard labeling practice to avoid excessive heat.