How we study the microbes living in your gut | Dan Knights

翻译人员: Carol Wang 校对人员: Tianji (Homer) Li

If I asked you to name a microbe that's living in your gut,

如果请你举例说出一个 生活在你肠道里的微生物，

many of you would probably say E. coli.

很多人可能会说大肠杆菌，

A lot of people say this. It's the best-known of the gut microbes.

确实很多人都这么说。 大肠杆菌是最有名的肠道微生物，

But it turns out that E. coli is outnumbered in your gut

但事实证明, 大肠杆菌只占你肠道中

细菌数量的1‰，

about a thousand to one

by other species, many of which you probably haven't heard of.

其它很多细菌你可能听都没听过，

These are Bacteroides; Prevotella is another example.

像类杆菌属的细菌； 另一个例子是普氏菌。

Those are the two that dominate the modern human gut.

在现代人的肠道菌群中， 这两种细菌占主导地位。

There are about a hundred trillion microbes living inside you.

人体内生活着约100万亿的微生物，

We call this your microbiome,

我们称之为微生物群，

so it's like a little world living inside you --

它们就像生活在 你体内的一个小世界——

actually more like a universe.

实际更像一个宇宙。

A hundred trillion means if you took a blade of grass

100万亿的数量概念是这样的，

如果一根草 代表一个生活在你肠道内的微生物，

and planted it for every microbe living in your gut,

that could fill a million football fields.

那么就可以种满100万个足球场。

So it's incredibly complex.

因此这是一个难以置信的复杂系统。

But interestingly,

但有趣的是，

as our bodies have been adapting to life in modern society,

随着我们的身体逐渐适应现代生活，

we're losing some of our normal microbes,

我们正在失去一些正常的微生物，

与此同时，

and at the same time,

在世界发达国家，

there are quite a few diseases related to the gut

that are skyrocketing in developed nations all around the world.

很多与肠道有关的疾病正在飙升。

And many of you probably know someone who suffers from obesity,

许多在座的各位 可能就认识一些饱受肥胖症、

diabetes, Crohn's disease or ulcerative colitis,

糖尿病、节段性回肠炎 或溃疡性结肠炎、

allergies and asthma.

过敏和哮喘疾病之苦的患者。

Every one of these diseases

和许多

and many others related to metabolism and autoimmunity

与新陈代谢及自身免疫相关 的病症一样，

这些疾病都与肠道（菌群） 缺少健康多样性有关。

are linked to a loss of healthy diversity in the gut.

My lab got our first indication of this

我的实验室在研究非人类 ——灵长类动物时,

when actually we were studying non-human primates.

我们想了解 当猴子由丛林搬到动物园后，

We wanted to find out what happens to a monkey's microbiome

它们体内的微生物群 会发生什么变化。

when they move from the jungle to a zoo.

Does their microbiome change? Do they pick up new bugs?

它们体内的微生物群改变了吗？ 是否增加了新微生物？

Do they lose some? Does it get better or worse?

失去一些微生物吗？ 微生物群是在变好，还是变糟呢？

We tracked two different species in the jungle,

我们分别对丛林中（生活的） 两个不同物种进行了追踪研究，

一个物种在越南， 一个在哥斯达黎加，

one in Vietnam, one in Costa Rica,

and then we sequenced the DNA from their stool.

我们用它们的粪便 进行了DNA测序，

This is how we study the microbiome in my research lab.

这就是我们实验室 对微生物进行研究的方法。

通过DNA比对，我们发现 野外的这两个物种体内，

And what we found in the DNA is that in the wild,

these two species had totally different sets of microbes.

微生物群截然不同。

It was like a fingerprint for the species.

微生物群 就像物种的指纹一样。

But in the zoo, they had lost most of that diversity

但在动物园里, 它们的微生物群 却失去了大部分的多样性，

并获得了一些其它的微生物，

and had acquired some other set of microbes.

So this was very curious.

这种现象非常奇怪。

We've got these two different microbiomes.

我们有两个不同的微生物群：

In the wild, picture a lush tropical rainforest

野外动物体内的微生物群，

它就像郁郁葱葱的热带雨林 活在这些猴子的肠道内，

living the guts of these monkeys.

That's the kind of diversity that we're talking about.

也就是我们说的多样性；

然而在动物园里, 它们 （微生物群）却失去了多样性，

Then in the zoo, they've lost diversity.

Picture a rainforest that's been burned to the ground

就好像一些入侵物种

接管了烧光的雨林，

and taken over by a few invasive species.

That's more like the microbiome in a captive primate.

因此它们更像圈养灵长类 动物体内的微生物群。

Now, in the meantime,

与此同时，在动物园里，

many of the animals in the zoo are not doing so well.

许多动物身体状况都不太好，

They have issues with obesity,

它们有肥胖、

wasting,

消瘦、

肠胃炎、腹泻、腹胀等问题，

gastroenteritis, diarrhea, bloating,

有些动物几乎活不下去了。

and some of them were barely holding onto their lives.

Now, of course, we were very interested to find out

因此，我们对找出这些 所谓的入侵物种很感兴趣，

what are these so-called invasive species that are taking over in the zoo.

它们主宰着动物园里 动物体内的微生物群。

So we went back to the DNA, and what the DNA told us

所以我们分析了它们的DNA，

is that every monkey in the zoo

发现动物园里的 每只猴子的肠道内

had become dominated by Bacteroides and Prevotella,

都被类杆菌和普氏菌所主宰，

the same microbes that we all have in our guts as modern humans.

这些猴子和现代人肠内 拥有相同的微生物群。

We wanted to find a way to visualize this,

为找到让这一发现结果 可视化的方法，

and we used some tools from multivariate ecology

我们使用了一些多元生态学工具,

to put all of the microbiomes we were studying onto an axis.

把我们研究的微生物群 放在（坐标图的）轴线上。

这里你看到的是一个距离图，

And what you're seeing here is a distance plot

where every point is a different animal's microbiome.

每个点代表着 不同动物的微生物群，

所以，每一点也代表了 整个动物园的微生物。

So every point represents a whole zoo of microbes.

And the microbiomes that have a lot of microbes in common

如果不同微生物群中 彼此的微生物相似的话，

它们在图中的距离就很近；

are close to each other.

The ones that are very different are farther apart.

差异很大的微生物群， 在图中则离彼此很远。

So this is showing you

这里展示的是：

that the two groups of wild monkeys are over on the left.

最左边的点 代表两组野外的猴子，

The top left are these highly endangered monkeys

左上方的点是 高度濒危的越南猴，

叫做白臀叶猴，

called the red-shanked douc in Vietnam.

And at the bottom left are monkeys from Costa Rica.

左下角的点则是 来自哥斯达黎加的猴子。

So you can see that they have totally different microbiomes in the wild.

从图中看出，野外生活的猴子 有着完全不同的微生物群。

And then the same two species of monkey in the zoo are converging,

而在动物园里，这两种猴子 （的微生物群）正在汇合，

so their microbiomes change

它们的微生物群改变了，

and they become much more similar to each other,

变得更加相似，

尽管它们（猴子）来自 不同大洲的动物园、

even though these are zoos on different continents,

不同的地理区域和不同的饮食。

different geographical regions, and they're eating different diets.

Now, we did study some other species of primate.

我们也研究过 其他种类的灵长类动物，

What species of primate do you think is even more divergent

你觉得哪种灵长类动物

比圈养的灵长类 更加与野生灵长类不同？

from the wild primates than the captive primates?

Modern humans.

是现代人类！

These are humans living in developing nations.

图中这些点代表 生活在发展中国家的人，

So they were more different from the wild primates

和物园里的灵长类比起来，

than those in the zoo.

他们与野生灵长类更加不同。

And the final group that we studied, all the way on the right,

我们研究的最后一组 在图中最右边，

is people living in the USA.

他们是生活在美国的人们。

And when I saw this figure,

当我看到这个图时，

the hairs raised up on the back of my neck,

脖子后面的汗毛都竖起来了！

因为一种解释是, "我的妈呀，太有趣了，

because one way to think about it is, "Oh, that's interesting,

captive monkeys are sort of on their way to becoming like Americans."

圈养的猴子 快变成美国人了！“

(Laughter)

（笑声）

But the other way to think about it

但另一种解读则是，

is that Americans are like super-captive monkeys.

美国人就像超级圈养的猴子。

And I was actually looking at this figure on my computer screen

当我听到四只动物园白臀叶猴

when I got the news that four of the red-shanked doucs

因为肠道疾病而死的消息时，

had died in the zoo of gut-related issues.

我正看着电脑屏幕上的这个图。

So for some of these animals,

因此，对这些动物来说,

having the right microbes living inside them

它们体内 是否生存着正常的微生物，

may be a matter of survival.

可能是个生死攸关的问题。

Now this brings us to the human part of the story.

我们自然就要谈到人的问题，

Obviously, the microbiomes in the USA

显然，美国人体内 微生物群的失衡，

aren't causing premature death as frequently as in the zoo,

并没有造成 像动物园那么多夭折，

but we have major risk of obesity, diabetes,

但我们有肥胖、糖尿病、

a number of these other diseases.

和其他类似疾病的高发病率。

不仅是在美国生活了好几代的人

And this applies not just to people who have been living in the USA

for many generations,

存在这样的问题，

but also to immigrants and refugees,

而且新移民和难民也一样，

多数移民 和难民群体抵达美国时，

who, for most immigrant and refugee groups,

arrive in the USA metabolically healthy,

他们在新陈代谢方面很健康，

and then within a few years,

然后，在几年之内,

他们患上肥胖和糖尿病的风险

they become just as high-risk for obesity and diabetes

as other Americans.

与美国人一样高。

And we discussed this issue with two groups

我们与两个 从东南亚迁来美国的团体

that have been coming to the USA from Southeast Asia:

讨论过这个问题：

一个是洪族人，因越南战争 和老挝美国秘密战争，

the Hmong, who started coming in the mid-1970s

as refugees from the Vietnam War and the US secret war in Laos;

从 20 世纪 70 年代中叶开始， 他们以难民身份来到美国；

and the Karen, who have been coming more recently as refugees from Myanmar.

另一个是凯伦人， 最近才从缅甸来的难民。

So we've been working for a few years

我们已经与这些当地社区

和临床医生一起工作了几年，

with these local communities and clinicians

to study what happens to the Hmong and Karen microbiomes

研究洪族人和凯伦人 从泰国难民营和村庄来到美国后，

when people move from refugee camps and villages in Thailand to the USA.

他们体内的微生物群 会发生怎样的变化。

And what we found

我们发现，

is that when people come to the USA from these groups,

当这些人来到美国后，

they lose a large fraction of their microbiome,

他们体内的微生物群 失去了很大一部分，

somewhere around 20 percent,

约 20%；

and those who come to the USA and become obese

而那些来美国后 患肥胖症的人，

则失去了(原来) 微生物群的三分之一。

lose about a third of their microbes.

So we know that moving to the USA

因此，我们得出结论，

is sufficient to cause a dramatic change in your microbiome,

移居到美国生活后，会造成 体内微生物群发生巨大改变，

probably not for the better.

很可能不是在变好。

Are these microbes actually causing the obesity,

这些微生物群 真的会导致肥胖，

or is the obesity causing a change in the microbes?

还是肥胖造成了 微生物群的改变？

This is something that we're following up on,

这是我们正在跟进的事情，

我们实验室发现的证据，

and the evidence we have now in my lab

combined with evidence from a number of labs around the world

以及来自世界各地一些实验室的 证据都告诉我们，

tells us that certain changes in the microbiome

微生物群的某些变化

会导致肥胖、

do lead to obesity,

and a number of other modern, kind of Westernized diseases.

以及其它一些现代病， 或者说西方病。

The good news is that your microbiome can actually change.

好消息是，你体内的 微生物群是可以改变的。

Unlike your own genome,

和你的基因组不同的是，

it's a living, breathing thing,

它（微生物群）是活生生、 会呼吸的东西。

and there's a broad front of research happening right now

（科学家们）正在进行 一项广泛的前沿研究，

to better understand how we can restore our microbiomes

以便更好地了解 当微生物群出现问题时，

when something goes wrong,

如何通过饮食、

using diet,

使用活的微生物，

using live microbes.

去恢复体内的微生物群。

And in fact, one of the next steps for us

事实上, 我们下一步要做的是，

is collecting and preserving microbes from healthy people around the world

为那些（患病）的人群收集和保存 来自世界各地健康人士的微生物，

so that they can be kept as cultural assets for those groups

以便作为文化资产进行保存，

to potentially protect them as they adapt to modern society,

在他们适应现代社会时， 对之进行潜在保护；

and to protect future generations

保护正在成长、

who are currently growing up to have increased risk of these diseases

后代有较高风险

患西方病的这一代人，

with every generation.

I'm looking forward to a future

未来，我期待，

会有我们需要的工具，以修复 和补充我们体内的微生物群，

where we have the tools that we need to restore and replenish our microbiomes,

and in that world, the monkeys will live happier and healthier lives,

在未来世界里，不但猴子们 会过上更快乐、更健康的生活，

and so will we.

我们也会！

(Applause)

（掌声）