According to a study done at the University of Colorado and posted on Bacteriality, there are nearly 332,000 genetically distinct bacteria on the human hand. These bacteria belong to 4,742 different species.
Bacteriality says that the results of the study came from a test that was preformed on 51 undergraduates. The species of bacteria that live on each person's hands differs greatly. During this test, only five species of bacteria were found on all the students' hands. Even two hands belonging to the same person only had around 13 percent of the same bacterial species in common. The results also showed that men have less bacteria on their hands than women.