We are only now beginning to learn the impact the gut-based bacterial community can have on an adult human. In this respect, scientists know more about bees than about human beings. For bees, having more diverse gut bacteria has been a more successful evolutionary strategy. They were only able to evolve from their carnivorous wasp ancestors because they picked up new kinds of gut microbes that were able to extract energy from plant pollen. That allowed bees to become vegetarians.
