Simplify the following text for a Grade 5 native English-speaking person.
Original: A strain of E. coli is a sub-group within the species that has unique characteristics that distinguish it from other E. coli strains .
Simplified: Escherichia coli or E. coli is a bacterium that can be found in human intestines . Scientists have studied E. coli very well , and know more about how E. coli cells work than any other organism .