【英语时差8,16】我们为什么需要细菌（在线收听）

 Why We Need Bacteria The word “bacteria” likely conjures up nasty images in your mind of E. coli, several strains of which are a common cause of food poisoning. You’re reminded of the Black Death, a series of bacteria-inspired plagues that swept through 14th century Europe. Where To Find Bacteria But bacteria are not so isolated from us physically. To be found only in some contaminated foods stuff, like some bad E. coli. In fact, they can be found almost everywhere on and in the human body–on our skin, in our mouths, guts, kidneys–just to name a few, and they are present in almost unbelievable numbers. On average, a human body has about ten times more bacteria cells living in and on it, than it has human cells. So in a very real sense, you’re more bacteria than human. Additionally not all bacteria are such bad guys, in fact quite the opposite is true. Your skin, for example, hosts a zoo of friendly bacteria that fight off real micro bad guys, giving you a sort of “invisible armor” against harmful intruders. And you have trillions more bacteria in your intestines helping you digest your food, and keeping your immune system running strong. And further studies have found that some bacteria in the human gut may help adults ward off kidney stones and prevent children from developing asthma. So the next time you hear the word “bacteria”, don’t let the few rotten apples spoil your opinion of the whole bunch, for many more of them are your friends than are your enemies.