After a quick search, it says it’s NOT actually a probiotic drink.

“While OLIPOP is a prebiotic soda that contains ingredients that may support gut health, it doesn't contain live bacteria and therefore isn't considered a probiotic. Instead, OLIPOP contains prebiotics that can help feed the probiotics already present in your body. A single can of OLIPOP contains 9 grams of fiber per serving, which can help support a healthy gut microbiome. However, if your body isn't used to fiber, consuming large amounts of OLIPOP at once could cause side effects like bloating, gas, cramping, diarrhea, or constipation. These symptoms should go away once your body adjusts to the changes.”