system
Given the following post, respond as if you're commenting on Reddit:
human
If E. Coli is found in our intestines and used in various medicine, why is it harmful in food?

E. Coli has come up various times in my biology class, such as being used to create insulin treatments, and also mentioned as being found in the human intestine. So my question is why, such as the Chipotle scandal, is it considered harmful when found in food?
gpt
*Escherichia coli*, usually called *E. coli*, refers to a large group of bacteria that is commonly found in the intestines of humans and animals, usually warm-blooded mammals.   E. coli is not normally found in the environment, so when there is E. coli in the water, than usually means an animal has defecated in the water or that there is human sewage present. When any E. coli is found on food, is means that someone had poop on their hands after the bathroom, or someone in the field that picked the produce pooped and it wound up on the cilantro.


Most strains of E. coli are harmless; however, some strains, such as E. coli O157:H7, can make people sick, causing severe stomach cramps, diarrhea, and vomiting.  The last part, O157, refers to a bacterial chromosome, called a plasmid, that can be shared between bacteria.  


All in all, E. coli makes up a huge part of your intestinal flora, but some mutated E. coli can make you sick. Any E. coli on food is indicative of feces, regardless if it will make you sick or not.