Probiotics are having a moment—and in no small way thanks to Smolyansky’s Lifeway and its yogurt-like kefir. She’s grown the company, with $130 million in gross sales, into the largest kefir outfit in the U.S. since taking over the family business in 2002. Her dedication to R&D has been a major contributor to the expansion of her healthy-bacteria empire. In addition to rolling out new products like high-protein kefir, Smolyansky is pushing into new categories such as probiotic pills and supplements—both of which are in currently in development. A recently acquired Wisconsin facility, which just started production, will increase the company’s output by fivefold. International markets are next, with Lifeway’s entry into Mexico in June and Europe in its sights.