Probiotics have become a familiar category for consumers, with product options spanning supplements, foods, beverages, skin care, animal nutrition and more. Sales of prebiotics, probiotics and synbiotics—a combination of the two—are estimated to exceed US$3 billion in 2020. Food and beverage is predicted to experience the most growth, whether in traditional refrigerated offerings such as yogurt, kombucha and kefir, or shelf-stable products like baked goods, frozen meals and hot beverages, which use spore-forming bacteria.