Coca-Cola is launching a prebiotic soda brand called Simply Pop, taking on upstarts Olipop and Poppi.Starting in late February, consumers on the West Coast and in the Southeast will be able to try Coke's iteration of the trendy drink.Soda consumption has broadly fallen in the U.S. over the last two decades, hurt by health concerns and an increase in alternatives on the market, from cold brew to energy drinks to water. But in the last five years, sodas containing prebiotics have taken off, thanks to industry ...