It’s no wonder that giant pandas are always chewing and eating, say Chinese researchers: their gut bacteria are not the type for efficiently digesting bamboo. The bamboo-eating giant panda actually harbors a carnivore-like gut microbiota predominated by bacteria such as Escherichia/Shigella and Streptococcus, according to new research. Giant pandas evolved from bears that ate both plants and meat, researchers said, and started eating bamboo exclusively about two million years ago.