Okay so of course everyone know what E-coli is, it’s a bacteria that can cause food poisoning. But a few years ago in biology class I realized it’s also a microbe in our gut system. So how does something that’s dangerous live inside our gut without affecting us?
In: 2
It’s mostly harmless. E Coli is all over the place, you ingest it regularly. Only some strains of it, mostly from cattle, IIRC, are dangerous.
I’ll try to go for a true ELI5 here. The E. coli which lives in our gut is harmless because it’s the domesticated variety. But sometimes these bacteria can become wild and dangerous, and that is the pathogenic variety. They will attempt to make a living from the parts of a human body that they are not supposed to, causing disease.
Strains that cause diseases have evolved to produce toxins or invade through intestinal lining, unlike e coli that, along many other bacteria, lives in our digestive tract without harm. Some of notable ones are enteropathogenic, enterotoxigenic, enterohaemorrhagic etc.
It’s harmless if it stays where it is I.e the gut but can cause problems if it goes elsewhere such as the urethra which causes about 90% of urine infections
E. coli is usually harmless. Its presence just shows that water has been probably contaminated with sewage water or sth similar, and that is why it makes us concerned
E. Coli is a family. The E. Coli that usually lives in your gut is harmless and for lack of a better comparison: domesticated. It evolved together with humans. Both humans and the E. Coli are better off for having eachother. They help you digest stuff, while getting a meal for themselves. Give and take. But there are also strains, that are more selfish. If you get infected with one, you get food poisoning. Your body recognises that they’re selfish, and wants to get rid of them. Diarrhoea ensues.
Your gut are a good living spot for bacteria. Food, safety, constant climate. There’s always a battle going on, between different types of bacteria and other micro-orgsnisms. A bit like at a concert without reserved seats: everyone wants the best spots in the front. Having the best sport already taken by the nice guys, the bad guys (hooligans?) don’t have a chance. That’s why anti-biotics often give you diarrhoea, they wipe out 90 percent of all bacterie, the good guys just as much as the bad guys, so the battle for the best spots start again.
Your body does have a few tricks up its sleeve to make it a more hospitable place for the good guys, and less attractive for the bad guys. Diarrhoea, immune system, motility, to name a few.
*E. coli* is a bacteria that thrives in the guts of mammals. Not all *E. coli* cause food poisoning, only certain varieties do, and the variety people have in their guts are harmless to people (so long as they stay in the gut).
There are a few different kinds of *E. coli* that make people sick: *E. coli* O157 and *E. coli* O104, for instance, make a toxin that breaks open blood vessels in the gut and causes pain, bleeding, and diarrhea. There are others that cause diarrhea by irritating the gut or sticking to the walls of the gut.
Latest Answers