10 Questions The Human Microbiome Test your knowledge about the microbes that live in and on us in this 10-question quiz! AMNH_Official, 04/27/2018 answers Play Why do scientists call humans "superorganisms"? humans are the smartest organisms on Earth humans are such large organisms compared to most humans are an ecosystem for many other organisms What percent of all the cells in the human body are bacterial cells? less than 10% about 30% more than 70% How do microbes keep us healthy? they produce vitamins they boost our immune system they produce vitamins and boost our immune system … and 7 more awesome questions! Check them out by clicking “Play”.