we each view ourselves as a unique and independent individual,

我們視自己為獨一無二的個體

but we're never alone!

但我們永遠不孤獨！

Millions of microscopic beings inhabit our bodies,

上百萬的微生物以我們的身體為家

and no two bodies are the same.

每個人的身體都不一樣

Each is a different habitat for microbial communities:

但大家都提供微生物聚落不同的棲地

from the arid deserts of our skin,

從如荒漠的皮膚表面

to the villages on our lips,

到嘴唇上的微生物村落

and the cities in our mouths.

口腔內的城市

Even every tooth is its own distinctive neighborhood,

甚至每一隻牙齒都是獨特的鄰里

and our guts are teaming metropolises of interacting microbes.

而我們的腸道如大都會般充滿了微生物

And in these bustling streets of our guts,

在腸子壅擠的街道裡

we see a constant influx of food,

有源源不絕的食物

and every microbe has a job to do.

而每一種微生物都有自己的工作

Here's a cellulolytic bacteria, for example.

比如說，纖維素分解性細菌

Their one job is to break down cellulose,

它們的唯一工作就是分解纖維素

a common compound in vegetables, into sugars.

一種在蔬菜和醣類中常見的分子

Those simple sugars then move along to the respirators,

分解後的糖會輸送至行呼吸作用的細菌

another set of microbes that snatch up

這些微生物會吸收簡單糖類

these simple sugars and burn them as fuel.

並將之作為生物能源

As food travels through our digestive tract,

食物通過我們的消化道時

it reaches the fermentors who extract energy from these sugars

發酵性細菌會把糖轉變成

by converting them into chemicals,

酒精以及二氧化碳等分子

like alcohol and hydrogen gas,

將之當廢物排放

which they spew out as waste products.

為了汲取化學反應中的能源

Deeper in the depths of our gut city,

在腸道城市的更深處

the syntrophs eke out a living off the fermenters' trash.

互營細菌以發酵細菌的廢物維持生命

At each step of this process,

這過程的每一步

energy is released,

都會釋放出能量

and that energy is absorbed

那能量

by the cells of the digestive tract.

就被消化道的細胞吸收

This city we just saw is different in everyone.

這微生物城市在每人體內都不同

Every person has a unique and diverse community of gut microbes

每個人都有既獨一無二又多元的腸菌群體

that can process food in different ways.

可以以不同的方式處理食物

One person's gut microbes may be capable

某人的腸內菌可能只能

of releasing only a fraction of the calories

釋放出食物中少部分的卡路里

that another person's gut microbes can extract.

但另一人的腸內菌卻能全盤釋出

So, what determines the membership of our gut microbial community?

什麼因素決定我們腸裡有哪一種細菌呢?

Well, things like our genetic makeup

其實，我們的基因

and the microbes we encounter throughout our lives

以及我們一生中接觸到的菌種

can contribute to our microbial ecosystems.

都能影響我們體內的微生物生態系

The food we eat also influences

我們吃的食物也會影響

which microbes live in our gut.

是哪些微生物住在我們的腸子內

For example, food made of complex molecules,

譬如說，由複雜分子構成的食物

like an apple,

像是蘋果

requires a lot of different microbial workers to break it down.

需要許多不同的微生物幫忙分解

But, if a food is made of simple molecules,

但是，由簡單分子構成的食物

like a lollipop,

像是棒棒糖

some of these workers are put out of a job.

會使一些微生物失業

Those workers leave the city, never to return.

而這些微生物就此出城，再也不回

What doesn't function well are gut microbial communities

而只有少許物種的腸內菌落

with only a few different types of workers.

無法良好運作

For example, humans who suffer from diseases

例如，患有糖尿病或腸躁症的人

like diabetes or chronic gut inflamation

例如，患有糖尿病或腸躁症的人

typically have less microbial variety in their guts.

通常擁有較不多元的腸內菌落

We don't fully understand the best way

我們還不了解

to manage our individual microbial societies,

如何最有效地管理體內的微生物社會

but it is likely that lifestyle changes,

但是生活方式的改變

such as eating a varied diet of complex, plant-based foods,

像是攝取多樣、複雜的植物性食物

can help revitalize our microbial ecosystems in our gut

可以幫助活化我們腸內、以及身體各處

and across the entire landscape of our body.

的微生物生態系

So, we are really not alone in our body.

我們真的不是單單佔有我們的身體

Our bodies are homes to millions of different microbes,

有上百萬的微生物以我們的身體為家

and we need them just as much as they need us.

而我們必須互相依存

As we learn more about how our microbes

隨著我們對於這些微生物的互動

interact with each other and with our bodies,

以及對我們身體的影響知識增長

we will reveal how we can nurture

我們就能了解如何滋養

this complex, invisible world

這個複雜、隱形的世界

that shapes our personal identity,

這世界影響我們的個性

our health,

我們的健康

and our well-being.

以及我們的幸福