Synbiotics are a combination of prebiotics and probiotics that are believed to have a synergistic effect by inhibiting the growth of pathogenic bacteria and enhancing the growth of beneficial organisms. Synbiotics and other functional foods are now being considered important tools to help maintaining humans and animals in good health, for prevention of disease, and/or as alternatives for reducing the risk associated with diseases. Studies conducted on the relationship of the microbiota of human gut and animal gut and immunology have highlighted the role of synbiotics in the health of mammals. A synbiotic containing 109 CFU of the Bifidobacterium breve strain Yakult and 5.5 g of galactooligosaccharide (GOS) was shown to improve colonoscopic findings and fecal concentrations of Bacteroidaceae