The dr said I need a pro-biotic

This might explain why:

"Many probiotic bacteria are naturally sensitive to heat and moisture. Heat can kill organisms and moisture can activate them within pills, only to die due to lack of nutrients and a proper environment. These products should ideally be refrigerated and kept out of humidity. However, probiotics with freeze-dried organisms (which includes most sold as supplements in tablet or capsule form) and in packaging to prevent moisture, such as blister packs, generally do not need refrigeration or to be kept out of humidity but should still not be exposed to heat above room temperature. They also have longer shelf-lives than products containing live cultures, such as yogurts and drinks (which must be refrigerated). Probiotic yeast and some of the spore-forming bacteria, such as Bacillus coagulans, generally do not require refrigeration."

Another:

1. Don't probiotics need to be refrigerated?

It depends. Some probiotics do require refrigeration because the bacteria will die if left at room temperature. If they can't survive room temperature, however, how can they survive the harsh acidic environment of the stomach? They can't.

It used to be commonly understood that "living bacteria" was the "best." Research has come a long way, and we now know there are certain strains, like the bacillus, that can survive the stomach and make it all the way to the intestines where they are needed most.

Unfortunately, the idea was so prevalent that many people today are still leery of an unrefrigerated probiotic. Many companies still offer refrigerated probiotics, further perpetuating the myth. However, the most important thing to look for in a quality probiotic are strains that have been tested to survive the digestive system, which means they need to survive outside the refrigerator as well.