HSD Cat Adult Perfect Digestion Chicken 13lbsHill's Science Diet Feline Adult Perfect Digestion Chicken 13lbs Every cat has an entire ecosystem living within them the gut microbiome, full of billions of desirable and undesirable bacteria unique to your pet. With the right nutrients to help balance their microbiome, you can actually affect not only their digestive health, but their overall well being. That's why we developed Hill's Science Diet Perfect Digestion dry cat food with our ActivBiome+