The immune system of infants and young children is not fully developed. In this period, nutrition is important for both growth and health. Many scientific studies have identified the presence of pathogens or opportunistic pathogens in follow-on formulas and supplementary foods. Contamination of these foods with microorganisms should be prevented during raw material, production, storage and consumption stages. Identification of microorganisms in the food of infants and young children is possibly important for public health. In this study, it is aimed to give information about pathogens, opportunistic pathogens and public health risks in infant and young children’s food.time. The need for comprehensive studies on host immune response is evident.