Heribert Watzke: The brain in your gut

譯者: Nim Chen 審譯者: Ching-Yi Wu

This technology

這項技術

made a very important impact on us.

對我們產生了巨大的影響

It changed the way our history developed.

它改變了我們人類歷史發展的方向

But it's a technology so pervasive,

但是它是如此的普遍

so invisible,

如此的難以察覺

that we, for a long time,

以至於長久以來

forgot to take it into account

當我們在討論人類歷史時

when we talked about

總是忘記將它納入考量

human evolution.

.

But we see the results of this technology, still.

但是我們仍然看到了這個技術的影響

So let's make a little test.

現在，我們來做個小小測試

So everyone of you turns to their neighbor please.

請每個人面向自己身邊的人

Turn and face your neighbors.

面向自己座位旁的人

Please, also on the balcony.

看台上的人也請這麼作

Smile. Smile. Open the mouths.

笑，打開嘴巴

Smile, friendly.

友善的微笑

(Laughter)

.

Do you --

你是否

Do you see any Canine teeth?

你是否看到對方的犬齒？

(Laughter)

.

Count Dracula teeth

數數在你身旁的人嘴裡

in the mouths of your neighbors?

有幾顆像吸血鬼的尖牙？

Of course not.

當然沒有半個

Because our dental anatomy

因為我們牙齒型態

is actually made,

的安排與設計

not for tearing down raw meat from bones

並非用來嘶咬骨頭上的生肉

or chewing fibrous leaves for hours.

或花許多時間咀嚼充滿纖維的葉子

It is made for a diet

而是設計來咀嚼

which is soft, mushy,

柔軟、糊狀

which is reduced in fibers,

纖維量少

which is very easily chewable

易咀嚼及

and digestible.

消化的食物

Sounds like fast food, doesn't it.

聽起來很像速食，不是嗎？

(Laughter)

.

It's for cooked food.

我們的牙齒是設計給烹煮過的食物

We carry in our face the proof

我們的臉，就是

that cooking,

烹煮

food transformation,

這個改變食物型態的技術

made us what we are.

型塑了現代人外型的證據

So I would suggest that we change how we classify ourselves.

因此我建議我們改變我們原先的自我分類

We talk about ourselves as omnivores.

我們總說人類是雜食性動物

I would say, we should call ourselves coctivors --

我倒覺得，我們該稱自己是熟食性動物（coctivors）

(Laughter)

.

from coquere, to cook.

衍伸自拉丁文的coqure （烹煮）

We are the animals

我們是

who eat cooked food.

吃熟食的動物

No, no, no, no. Better --

不不不，更好

to live of cooked food.

靠熟食生存

So cooking is a very important technology.

所以烹煮無疑是很重要的技術

It's technology.

這個技術

I don't know how you feel,

我不知道你們心裡怎麼想

but I like to cook for entertainment.

但我喜歡烹飪款待別人

And you need some design

而且你需要一些巧思

to be successful.

才能成功

So, cooking is a very important technology,

所以烹煮其實是一個很重要的技術

because it allowed us to acquire

因為它讓我們有機會演化、發展出

what brought you all here:

這個讓我們共聚一堂的器官：

the big brain,

大腦

this wonderful cerebral cortex we have.

我們有棒極了的大腦皮質

Because brains are expensive.

因為演化出大腦是如此昂貴

Those have to pay tuition fees know.

所以我們現在得付學費

(Laughter)

.

But it's also, metabolically speaking, expensive.

而就代謝而言，大腦是耗能的

You now, our brain is two to three percent of the body mass,

現代人的大腦大約僅佔身體總體重的2-3%

but actually it uses 25 percent of the total energy we use.

但它卻消耗了25%我們所攝取的能量

It's very expensive.

所以它非常耗能

Where does the energy come from. Of course, from food.

而這些能量要從哪裡來呢? 當然是從食物

If we eat raw food,

如果我們吃生的食物

we cannot release really the energy.

我們便無法好好的運用其所含的能量

So this ingenuity of our ancestors,

而我們聰明的祖先

to invent this most marvelous technology.

發明了這個非凡的技術

Invisible -- everyone of us does it every day, so to speak.

儘管每個人天天使用卻仍難以察覺

Cooking made it possible

烹煮這項技術

that mutations,

使得基因突變、

natural selections, our environment,

天擇以及環境

could develop us.

有機會影響我們的演化與發展

So if we think about

試想看看

this unleashing human potential,

這項被解放的人類潛能

which was possible by cooking and food,

便是因為烹煮與食物才有機會發展

why do we talk so badly about food?

為什麼我們如此關注食物

Why is it always do and don'ts

為什麼總要考慮吃或不吃

and it's good for you, it's not good for you?

或是哪些食物對你有益、哪些有害?

I think the good news for me

我想對我來說好消息是

would be if we could go back

如果我們回頭想想

and talk about the unleashing,

這項被釋放的潛能

the continuation of the unleashing of human potential.

以及它延續至今的各種影響

Now, cooking allowed also

烹煮這項技術

that we became a migrant species.

曾使我們成為遷徙性的物種

We walked out of Africa two times.

人類曾經兩次走出非洲

We populated all the ecologies.

我們幾乎占據了大多數的生態環境

If you can cook, nothing can happen to you,

只要會烹煮，生存幾乎沒什麼困難

because whatever you find,

因為不論你找到什麼

you will try to transform it.

你都能夠透過烹煮來使之可食

It keeps also your brain working.

因此讓你的腦袋能繼續運作

Now the very easy and simple technology

而這項簡單的技術

which was developed

在被發明後

actually runs after this formula.

便遵循這樣的模式

Take something which looks like food, transform it,

取得某些看起來像食物的東西，然後改變它們

and it gives you a good, very easy, accessible energy.

它們便能夠提供優質又方便的能量來源

This technology affected two organs,

這項技術影響了兩個器官

the brain and the gut, which it actually affected.

腦以及消化道，尤其是消化道

The brain could grow, but the gut actually shrunk.

人類的腦變大了，但消化道卻變小了

Okay, it's not obvious to be honest.

好吧，我承認看起來不是那麼明顯

(Laughter)

.

But it shrunk to 60 percent

但相對於其他靈長類動物

of primate gut

人類消化道佔總體重的

of my body mass.

比例減少了60%

So because of having cooked food,

因為烹煮過的食物

it's easier to digest.

更容易消化

Now having a large brain, as you know,

而擁有較大的腦，就我們所知

is a big advantage,

是非常有利的

because you can actually influence your environment.

因為它使人類有能力去改變生存環境

You can influence your own technologies you have invented.

改進既有的技術

You can continue to innovate and invent.

並且持續的創新與發明

Now the big brain did this also with cooking.

大腦也改進、創新烹煮方法

But how did it actually run this show?

這實際上是如何進行的呢？

How did it actually interfere?

大腦如何影響烹煮技術的發展？

What kind of criteria did it use?

而它所用的又是怎樣的準則呢？

And this is actually taste reward and energy.

實際上就是味覺、回饋與能量

You know we have up to five tastes,

人類具有五種味覺

three of them sustain us.

其中三個維持我們生存

Sweet -- energy.

甜味與能量的攝取有關

Umami -- this is a meaty taste.

甘味則是來自肉類

You need proteins for muscles, recovery.

蛋白質則是合成肌肉及復原體力所需

Salty,

鹹味

because you need salt, otherwise your electric body will not work.

人類需要鹽類，否則帶電的身體無法正常運作

And two tastes which protect you --

另外還有兩種味覺是用來保護人類

bitter and sour,

苦味及酸味

which are against

幫助我們分辨

poisonous and rotten material.

有毒及腐壞的食物

But of course, they are hard-wired

即使人類的味覺是天生的

but we use them still in a sophisticated way.

但使用味覺的方式卻是人為的複雜精巧

Think about bittersweet chocolate;

想想苦甜巧克力

or think about the acidity

想想優格的酸味

of yogurt -- wonderful --

多麼美妙

mixed with strawberry fruits.

混和著莓果的味道

So we can make mixtures of all this kind of thing

我們可將各種食材隨意組合

because we know

因為我們知道

that, in cooking, we can transform it

透過烹煮，食物得以轉化成

to the form.

更好吃、更營養的狀態

Reward: this is a more complex

回饋：這一點更複雜

and especially integrative

尤其是大腦在整合訊息

form of our brain

的狀態

with various different elements --

跟各種因素：

the external states, our internal states,

外部環境、內在狀態

how do we feel, and so on are put together.

我們的感受及其他因素等等，加總的影響

And something which maybe you don't like

有些食物可能我們並不喜歡

but you are so hungry that you really will be satisfied to eat.

但卻是餓到會心滿意足地吃下

So satisfaction was a very important part.

所以滿足感是很重要的因素

And as I say, energy was necessary.

如同我所說的，能量則是必要的

Now how did the gut actually

而消化道是怎樣

participate in this development?

參與烹煮技術發展？

And the gut is a silent voice --

消化道無聲地發言

it's going more for feelings.

仰賴知覺來傳遞訊息

I use the euphemism digestive comfort --

也就是消化時的舒適感

actually -- it's a digestive discomfort,

但實際上，消化不適的感覺

which the gut is concerned with.

才是身體所關注的訊號

If you get a stomach ache, if you get a little bit bloated,

比如說如果你胃痛或是胃脹氣

was not the right food, was not the right cooking manipulation

你就知道哪些食物不該吃、不該那樣料理

or maybe other things went wrong.

或者你吃的食物哪些地方不對勁

So my story is a tale of two brains,

所以我的故事是由兩個腦組成的

because it might surprise you,

而這大概會讓你覺得驚訝

our gut has a full-fledged brain.

我們的消化道也有個獨立成熟的大腦

All the managers in the room say,

有些人也許會說：

"You don't tell me something new, because we know, gut feeling.

「這又不是什麼新鮮事，因為我們知道腸胃感，就是直覺（gut feeling）

This is what we are using."

這個詞我們天天都在用啊！」

(Laughter)

.

And actually you use it and it's actually useful.

我們的確都有使用消化道腦，它也的確是有用的

Because our gut is connected to our emotional limbic system,

消化道與掌管情緒的邊緣系統互相連結

they do speak with each other

彼此互相溝通與傳遞訊息

and make decisions.

並作出決定

But what it means

我所指的

to have a brain there

消化道中的腦

is that, not only the big brain

說明不只是大腦

has to talk with the food,

會跟食物溝通

the food has to talk with the brain,

食物也必須要傳遞訊息給大腦

because we have to learn actually

因此，我們必須要

how to talk to the brains.

學著跟大腦溝通

Now if there's a gut brain,

此外

we should also learn to talk with this brain.

我們也應該學著跟消化道腦溝通

Now 150 years ago,

大約一百五十年前

anatomists described very, very carefully --

解剖學家便對消化道有了精準的描述

here is a model of a wall of a gut.

這是消化道管壁結構的示意圖

I took the three elements --

我列出了消化道的三個器官

stomach, small intestine and colon.

胃、小腸、結腸

And within this structure,

細看他們的結構

you see these two pinkish layers,

你可以看到兩層粉紅色的結構

which are actually the muscle.

這兩層是肌肉

And between this muscle, they found nervous tissues,

而在肌肉中間，便存在著神經組織

a lot of nervous tissues,

許許多多的神經組織

which penetrate actually the muscle --

這些神經穿過了肌肉

penetrate the submucosa,

也穿過了黏膜下層

where you have all the elements for the immune system.

黏膜下層與免疫系統有關

The gut is actually the largest immune system,

消化道其實是人體最大的免疫系統

defending your body.

防衛你的身體

It penetrates the mucosa.

這些神經組織也穿透黏膜層

This is the layer which actually touches the food you are swallowing

而此層直接與你所吃

and you digest,

以及所消化的食物接觸

which is actually the lumen.

也就是內腔

Now if you think about the gut,

想像一下你的消化道

the gut is -- if you could stretch it --

如果你拉開你的消化道

40 meters long,

它會有四十公尺長

the length of a tennis court.

大約是網球場的長度

If we could unroll it,

如果將它延展開

get out all the folds and so on,

將其中的皺摺都展開

it would have 400 sq. meters of surface.

它的表面積大約有四百平方公尺

And now this brain takes care over this,

而這隱藏在消化道的腦

to move it with the muscles and to do defend the surface

負責控制消化道肌肉的運作、保護消化道表面

and, of course, digest our food we cook.

當然，也消化烹煮過的食物

So if we give you a specification,

容我詳細說明消化道腦

this brain, which is autonomous,

消化道腦具有自主性

have 500 million nerve cells,

有五億個神經細胞

100 million neurons --

一億個神經元

so around the size of a cat brain,

大約跟貓的腦一樣大

so there sleeps a little cat --

這裡可說是睡著一隻小貓呢!

thinks for itself,

消化道會自己思考

optimizes whatever it digests.

並將消化所得的能量妥善運用

It has 20 different neuron types.

它有二十種不同的神經元

It's got the same diversity you find actually in a pig brain,

大約跟豬的腦一樣多樣化

where you have 100 billion neurons.

但人類的消化道有一千億個神經元

It has autonomous organized microcircuits,

而消化道有著自主的小型神經迴路

has these programs which run.

依照某些方式運行

It senses the food; it knows exactly what to do.

消化道可感受各種食物，並知道應該怎麼處理它們

It senses it by chemical means

藉著化學方式，還有

and very importantly by mechanical means,

更重要的，力學的方式來感受食物

because it has to move the food --

因為消化道必須要移動食團

it has to mix all the various elements

並且混合其它消化所需的

which we need for digestion.

各種元素

This control of muscle is very, very important,

所以消化道肌肉的控制是非常非常重要的

because, you know, there can be reflexes.

如你所知，

If you don't like a food, especially if you're a child, you gag.

如果不喜歡某種食物，特別是你年幼時，你會作嘔

It's this brain which makes this reflex.

就是消化道腦負責這樣的反射動作

And then finally,

最後

it controls also the secretion of this molecular machinery,

消化道腦也控制著某些分子的分泌

which actually digests the food we cook.

這些分子是用來消化食物的

Now how do the two brains work with each other?

而腦與消化道中的腦彼此如何合作

I took here a model from robotics --

在這用一個機械科學的模型來解釋

it's called the Subsumption Architecture.

稱為「包容式體系結構」

What it means is that we have a layered control system.

指的是我們有著層級式的控制系統

The lower layer, our gut brain,

較低層級的消化道腦

has its own goals -- digestion defense --

有著自己的職責：消化及防禦

and we have the higher brain

另外還有較高層級的腦

with the goal of integration

負責整合身體的各種訊息

and generating behaviors.

並引發行為

Now both look -- and this is the blue arrows --

看看藍色的箭頭

both look to the same food, which is in the lumen

大腦與消化道腦都能感覺腸腔中的食物

and in the area of your intestine.

也都感測著腸道中相同的區域

The big brain integrates signals,

大腦整合這些訊息

which come from the running programs

而這些訊息其實是來自

of the lower brain,

消化道腦（綠色箭頭）

But subsumption means

所謂的「包容式」，即

that the higher brain can interfere with the lower.

較高層級的腦可以影響較低層級的消化道腦

It can replace,

大腦可以取代

or it can inhibit actually, signals.

或者該說是抑制腸胃道的訊號（紅色箭頭）

So if we take two types of signals --

我用飢餓跟飽足感來說明

a hunger signal for example.

比方說，飢餓的訊號

If you have an empty stomach,

如果你肚子空空

your stomach produces a hormone called ghrelin.

你的胃便會產生一種叫作飢餓素（ghrelin）的賀爾蒙

It's a very big signal;

它是一種很強烈的訊號

it's sent to the brain says,

會被傳送至大腦並且對大腦說

"Go and eat."

「快去吃點東西!！」

You have stop signals --

但身體裡也存在著停止的訊號

we have up to eight stop signals.

我們有多達八種的停止訊號

At least in my case,

不過對我來說

they are not listened to.

這些抑制訊號通常不太管用

(Laughter)

.

So what happens

若大腦整合後的訊號

if the big brain in the integration

凌駕來自消化道的訊號

overrides the signal?

會如何呢？

So if you override the hunger signal,

比如說大腦不理會飢餓的訊息

you can have a disorder, which is called anorexia.

會產生叫作精神性厭食的症狀

Despite generating

雖然消化道產生了

a healthy hunger signal,

健康的飢餓訊號

the big brain ignores it

大腦仍然忽略這樣的訊息

and activates different programs in the gut.

並且啟動消化道的其他機制

The more usual case

不過更常見的例子是

is overeating.

吃得太飽

It actually takes the signal

大腦接收到飽的訊息

and changes it,

卻改變它

and we continue,

讓我們繼續吃

even [though] our eight signals would say, "Stop, enough.

雖然有八種訊號會說：「夠了！別吃了！

We have transferred enough energy."

身體已經獲得足夠的能量了！」

Now the interesting thing is that,

有趣的是

along this lower layer -- this gut --

觀察接受減重手術病人會發現

the signal becomes stronger and stronger

在較低層級的消化道中

if undigested, but digestible, material

在未消化但可消化的食物

could penetrate.

通過時

This we found from bariatric surgery.

這些飽足感的訊號會越變越強

That then the signal would be very, very high.

飽足感的訊號會非常、非常的高

So now back to the cooking question

現在，回到烹煮這項主題

and back to the design.

以及如何將它設計的更盡善盡美

We have learned to talk to the big brain --

我們已經知道如何跟大腦溝通

taste and reward, as you know.

也就是透過味覺及回饋

Now what would be the language

但是我們應該用什麼樣的語言

we have to talk to the gut brain

來跟消化道腦溝通呢？

that its signals are so strong

如何才能產生強烈到讓

that the big brain cannot ignore it?

大腦無法忽略的飽足訊號呢？

Then we would generate something

這樣我們就能

all of us would like to have --

如大家所願的

a balance between the hunger

在飢餓

and the satiation.

與飽足之間取得巧妙的平衡

Now I give you, from our research, a very short claim.

從我們的研究中可看出一點端倪

This is fat digestion.

這是一個脂肪消化的實驗

You have on your left

在左邊的是

an olive oil droplet,

橄欖油的油滴

and this olive oil droplet gets attacked by enzymes.

我們以酵素來分解這些油滴

This is an in vitro experiment.

這是一個體外的實驗

It's very difficult to work in the intestine.

因為很難在腸道中進行這樣的實驗

Now everyone would expect

每個人都料想得到

that when the degradation of the oil happens,

油滴會被分解

when the constituents are liberated,

油滴裡面的成分會被釋放出來

they disappear, they go away

然後油滴就消失了

because they [were] absorbed.

因為它們會被吸收掉

Actually, what happens is that a very intricate structure appears.

實際上，在消化過程中會產生一種很精巧的結構

And I hope you can see

希望大家可以看得清楚

that there are some ring-like structures in the middle image,

在中間的圖片，有一圈環狀的構造

which is water.

這是水

This whole system generates a huge surface

這樣的構造會創造出一個很大的表面積

to allow more enzymes

使得更多的消化酵素

to attack the remaining oil.

可以來攻擊、分解這些油滴

And finally, on your right side,

最後，在右邊的圖片

you see a bubbly,

你可以看到泡狀、

cell-like structure appearing,

類細胞的結構產生

from which the body will absorb the fat.

身體就是從這些結構吸收油脂

Now if we could take this language --

現在如果我們讓這樣的語言

and this is a language of structures --

這種結構的語言

and make it longer-lasting,

更持久

that it can go through

讓飽足感的訊號

the passage of the intestine,

穿過整個腸道

it would generate stronger signals.

它就能夠產生更強烈的抑制訊號

So our research --

所以我們的研究

and I think the research also at the universities --

以及其他的研究都指出

are now fixing on these points

問題其實是指向

to say: how can we actually --

我們該怎樣─

and this might sound trivial now to you --

這對你來說可能無關緊要─

how can we change cooking?

改變我們烹煮食物的方式

How can we cook

我們要如何烹煮

that we have this language developed?

讓食物表達出這些結構語言？

So what we have actually, it's not an omnivore's dilemma.

所以實際上我們面對的，並不是雜食性動物的難題

We have a coctivor's opportunity,

相反的，我們有的是熟食性動物的契機

because we have learned over the last two million years

因為我們已經從過去兩百萬年的經驗中學到

which taste and reward --

藉著味覺以及回饋

quite sophisticated to cook --

來設計精巧的飲食

to please ourselves, to satisfy ourselves.

來滿足、取悅我們自己

If we add the matrix,

故我們在飲食鐵三角中加入食物基質

if we add the structure language, which we have to learn,

將這些得去了解的食物結構語言納入考量

when we learn it, then we can put it back;

當我們習得這些知識，就能讓結構語言

and around energy,

成為圍繞著能量的第三個角

we could generate a balance,

我們就可以透過

which comes out

我們最基本的技術，也就是烹煮

from our really primordial operation: cooking.

在味覺、回饋、能量之間取得平衡

So, to make cooking really

而要使烹煮這件事

a very important element,

成為很重要的元素

I would say even philosophers have to change

我想連哲學家都必須要改變

and have to finally recognize

並且體認到

that cooking is what made us.

烹煮這項技術才是使我們之所以為我們的原因

So I would say, coquo ergo sum:

因此，我想說：coquo ergo sum (拉丁語)

I cook, therefore I am.

我煮故我在！

Thank you very much.

謝謝大家

(Applause)

.