Like the Earth, the human body is a planet teeming with wild life in the midst of fascinating landscapes. For the first time, a microscopic film safari traces these different life forms in and on the human body. These organisms thrive and compete, feed and reproduce, develop and die. In the course of the journey, it becomes clear that some of these organisms are useful and even vital for humans, while others are harmful. Nevertheless, they are all part of a sophisticated ecosystem that has developed over the course of evolution. The number of bacteria that the human body harbors is greater than the number of cells that make it up. Every human being is therefore in constant interaction with countless microorganisms.