Our bodies go through several changes throughout our lives. The same happens with the microbes that live with us. After all, these make up a big portion of the cells in our organism. But, in comparison with the cells that make up our tissues and organs, these microbes divide very quickly, making occasional errors in their genetic material (mutations) more common. These errors drive the evolution of microorganisms and account for, among other things, their likelihood of causing disease.
Click here for original story, How do bacteria evolve in the gut over the course of a year?
Source: Phys.org