我們身上的微細菌

you are full of bugs.

你身上好多細菌！

No, not cockroaches and ants. These bugs are tiny, single-celled bacteria you can't see. They blanket your skin. They also fill your stomach, intestines, lungs and mouth.

它們既不是蟑螂也不是螞蟻，這些小蟲子很小，肉眼難見的單細胞細菌，它們不僅覆蓋在你的皮膚上，而且也出沒於你的胃、腸、肺口腔內。

In fact, roughly 100 trillion of these microscopic critters live in (and on) the human body. A typical person contains only about 37 trillion human cells. In other words, bacteria might outnumber human cells in an average person by roughly three to one.

事實上將近約100萬億此類微生物寄居在你的身體內外。一個人僅有37萬億人類細胞。換句話說，人類身體上的細菌遠遠超出了細胞數量以1:3的比例存在着。

Bacterial cells are very small. All of these bugs make up only between 1 and 3 percent of your body weight.

細菌細胞非常小。但是這些討厭鬼足足佔了你體重的1%到3%呢！

We even pick up bacteria from family members - for example, when someone kisses us on the cheek.

此外，這些細菌還會通過家人侵入我們的身體-例如，有人親你臉蛋的時候。

You pick up some microbes from your mother during birth. As you grow, your body acquires more. For example, new microbes hop on when you play in the dirt or when a family member kisses your cheek.

分娩的時候媽媽便給寶寶留下了這些微小細菌，隨着你長大，你身上的細菌會變得更多。比如說，當你在較髒的環境下玩耍的時候或者家人親親臉蛋時這些細菌都會趁虛而入。

At this point, you might be starting to wish you could get rid of all those germs. But that wouldn't be a very good idea. The microbes in your body are crucial to your health. They churn out nourishing vitamins. They help digest your food. Some even keep other, dangerous bacteria from multiplying so you don't get sick.

如此說來，你可能開始想要擺脫這些細菌。這種做法不太明智，因爲這些細菌對你的健康還起着至關重要的作用，比如說他們會產出富含營養的維他命，幫助你消化食物，有的甚至還阻止其他危險細菌的繁殖來幫助你躲過感冒一劫。

In return, the bacteria get nutrients and a place to live. "It's a tit for tat," says Margaret McFall-Ngai. She is a microbiologist at the University of Wisconsin-Madison.

對於細菌而言，我們爲其提供營養以及居所作爲回報。美國威斯康星大學微生物學家Margaret McFall-Ngai無奈的感慨道：對於我們來說微生物細菌是一柄雙刃劍！