How many bacteria are there on hands?

150 species

Believe it or not, there are approximately 150 species of bacteria on our hands.   Not too many people know that we do not have too many types of bacteria in common.  It is interesting to know the fact that the left and right hands of the same individual shared only about 17 per cent of the same bacteria types.  What makes the difference?  The way each hand interacts with the environment is different.