microbiome in human gastrointestinal system human gut microbiome YH A microbiome located in a human gut. A human being's gut microbiota contains tens of trillions of microorganisms, including at least 1000 different species of known bacteria with more than 3 million genes (150 times more than human genes). Microbiota can, in total, weigh up to 2 kg. One third of our gut microbiota is common to most people, while two thirds are specific to each one of us. In other words, the microbiota in your intestine is like an individual identity card. URL: http://www.gutmicrobiotaforhealth.com/en/about-gut-microbiota-info/ human gut microbiota