▶ 科学60秒：你的微生物原住民，最爱哪一片皮肤？ | 1:15

Bacteria on the Skin You're In

根据《科学》上发表的一项研究，研究人员发现不同皮肤区域含有的细菌种类差异极大。

 [听力全文]（点击展开/收起）

Have you ever said, “I know it like the back of my hand”? Well, how well do you know the back of your hand? Or the back of your knee? Or behind your ears? Probably not as well as scientists at the National Institutes of Health who just completed a survey of the bacteria that live on the skin at various parts of the body. They found that different sites harbor different bugs, results published in the May 29th issue of the journal Science.

The skin, they point out, is a large ecosystem that includes a variety of ecological niches. Your moist armpit is like a tropical rainforest, whereas, not far away, your forearm is as smooth and dry as a desert. So the scientists took samples from 20 different body regions in 10 volunteers. And found that the microbes in your armpit are more like those in someone else’s armpit than the ones on your own forearm.

Dry skin showed the greatest diversity with an average of 44 different species found on the forearm. While the least diverse mix, with only 19 species, lives aft of your ears. So science-savvy moms: don’t worry about washing behind the ears. Instead, bug your brood to give those grubby forearms a good scrubbing.

—Karen Hopkin

 [重难点词汇、短语]（点击展开/收起）

niche: n. [生态] 生态位，又称生态龛，指一个种群在生态系统中，在时间空间上所占据的位置及其与相关种群之间的功能关系与作用

armpit: n. 腋窝

savvy: adj. 精明的，有见识的；n. 常识；技能

bug: v. 打扰，烦扰；窃听

brood: n. 一群，一窝

 [参考译文]（点击展开/收起）

你可能曾经说过：“我对一件事物了如指掌。”那么，你对自己的“指掌”究竟有多了解呢？对膝盖或者耳朵又有多了解呢？美国国立卫生研究院（National Institutes of Health）的科学家完成了人体多个部位皮肤上细菌分布的调查，他们发现，不同部位居住着不同的细菌，这项研究发表在5月29日的《科学》（Science）上。

他们指出，皮肤实际上是一个庞大的生态系统，包含了多种多样的生态位。潮湿的腋窝就像热带雨林，而离腋窝不远的前臂，却像沙漠一样平坦干燥。科学家从10名自愿者身上20个不同的身体部位采集了样本，发现相比同一个体不同部位的微生物（比如自己前臂与腋窝中的微生物），不同个体相同部位的微生物相似度更高（比如你的腋窝和别人腋窝的微生物）。

其中，干燥皮肤的微生物多样性最高：平均来说，前臂上发现了44种不同的微生物；而多样性最低的位置是耳朵后面，只有19种。怪不得那些见识广博的妈妈们会说：别太用心清洗耳朵后面，好好洗洗你那脏兮兮、容易窝藏细菌的前臂吧。

翻译 壮壮