Every human has a gut microbiota – you can’t live without it. The proportion of different microbial species in the digestive tract varies substantially from person to person. Your genes influence which gut microbes live inside you, contributing to the stability of your own microbial community, even though a variety of outside factors change your microbiota from hour to hour and from week to week.
Scientists are learning, though, that the names of your gut microbial species may be less important than what they do for you. The microorganisms that make up your community must perform certain important jobs.