Probiotic and prebiotic food products. Selection of food products and supplements containing probiotic cultures and prebiotic sugars. Probiotic cultures contain species normally found in the human gut flora, including species of Lactobacillus and Bifidobacterium. Prebiotics are non-digestible food ingredients (usually carbohydrates) that support the growth of probiotic bacteria in the large intestine. A preparation that combines both probiotic and prebiotic ingredients is known as a synbiotic.