What allows grass eaters to digest cellulose? Scientists are saying that it was a small step for the Panda to move from a meat diet to a grass diet. The article only refers to differences in the Panda's skull, presumably for better chewing. I've also heard that the Japanese are able to digest Nori because they have the right gut biome because Nori has been part of their diet and the appropriate bacteria has developed over time. Does that suggest that if the cellulose of bamboo and other grasses were pre-chewed by mechanical means and the right bacteria were introduced into the human gut that we would likewise be able to digest grasses? Related story

You might find the answers to a similar previous question interesting:

Human Digestion of Cellulose?

Summary of those answers: It seems that some humans do host cellulose-digesting symbiotic bacteria, and do digest some of their cellulose. According to Cellulose and the Human Gut, finely ground cellulose with low lignin content is most readily digested by humans who host the right bacteria.