ibson and Roberfroid de?ned a synbiotic as “a mixture of probiotics and prebiotics that bene?cially affects the host by improving the survival and implantation of live microbial dietary supplements in the gastrointestinal tract, by particularly stimulating the growth and/or by activating the metabolism of one or a limited number of health-supporting bacteria, and thus improving host welfare”. Since this ?rst de?nition, synbiotics have not been rede-?ned. However, Kolida and Gibson stated that both synergistic and complementary synbiotic approaches should be considered when applying synbiotics in animal science. From this, the synergistic effect of a probiotic is chosen based on effects on the host, while the prebiotic is chosen to speci?cally stimulate growth and activity of the probiotic