Every dog has an entire ecosystem living within them - the gut microbiome, full of billions of desirable & undesirable bacteria unique to your pet. The right nutrients can help balance their microbiome. You can actually affect not only their digestive health, but their overall well-being during their golden years. That's why we developed Science Diet Perfect Digestion dry dog food with our ActivBiome+ Technology ingredient blend of prebiotics. It's breakthrough nutrition supports a dog's unique gut microbiome for healthy digestion & balanced nutrition to help your dog age 7+ feel their best.