In our study, we will investigate the effect of dietary inulin, FOS obtained by inulin hydrolysis and lactosucrose during the larval rearing and weaning stages of turbot. This research will focus on the interaction between turbot, gastrointestinal microbiota, and microbes associated with live food organisms. Two consecutive experiments will investigate the effects of the prebiotics during the weaning and post-weaning stages and the larval rearing period. Two kinds of effects will be considered: - effects of prebiotics on survival, growth and weaning success of turbot; - effects of prebiotics on the microbial ecology in the digestive tract of turbot, and in live food organisms.