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Heribert Watzke談腸道中的大腦

Heribert Watzke: The brain in your gut

 

Photo of three lions hunting on the Serengeti.

講者:Heribert Watzke

2010年7月演講,2010年10月在TED上線

 

翻譯:洪曉慧

編輯:劉契良

簡繁轉換:洪曉慧

後製:洪曉慧

字幕影片後制:謝旻均

 

影片請按此下載

閱讀中文字幕純文字版本

 

關於這場演講

你知道腸道中大約有一億個有功能性的神經元嗎?食品科學家 Heribert Watzke告訴我們關於腸道中的「隱藏大腦」,以及它能讓我們感覺令人驚訝的東西。

 

關於Heribert Watzke

Heribert Watzke研究在我們腸道中的大腦,並致力於開發能滿足我們身心的新食物。

 

為什麼要聽他演講

Heribert Watzke在瑞士的雀巢研究中心成立了食品材料科學系,其中匯集了許多學科,包括:化學、營養學和神經科學,不斷追求更好的食品。Watzke的背景是化學;80年代中期,在他轉而研究材料科學之前,屬於雪城(Syracuse)一個開創性團隊的一份子,致力於將水分解成氫和氧,以創造替代性能源。

 

在雀巢實驗室,Watzke專攻人類最基本的能源形式:食品化學。他之前對食物的研究集中在感官性質-味覺、氣味、口感。但還有更多需要瞭解之處。食物的生物結構如何決定其性質、消化能力及營養品質?是什麼樣的科學機制將一個生物結構(如一顆榖粒)轉變成某種人類可以使之成為純粹能量(如一片麵包)的東西?他的團隊最近不斷尋找食物結構對脂肪消化的影響,用於對抗肥胖。有飽足感需要多少脂肪?我們如何最有效地與腸道中一億個神經元溝通?

 

「Heribert Watzke對科學有擋不住的熱情。在解釋一些科學觀點當中,他會忍不住拿出他的電腦,展示卡布奇諾奶泡沫形式的分子結構動畫。」

-雀巢研究中心

 

Heribert Watzke的英語網上資料

首頁:research.nestle.com

 

[TED科技‧娛樂‧設計]

已有中譯字幕的TED影片目錄(繁體)(簡體)。請注意繁簡目錄是不一樣的。

 

Heribert Watzke談腸道中的大腦

 

這項技術對我們有非常重要的影響,它改變了我們的歷史發展。但這個技術是如此的無所不在、如此無形,因此有很長一段時間,當我們談到人類的進化時,忘了考慮它。但我們仍可看到這種技術的結果。讓我們來做一個小測試:每個人都請轉向你身旁的人吧!轉身面對你身旁的人,請,看臺上的人也一樣。微笑、微笑、張嘴、友善的微笑。(笑聲)你們有看到任何犬齒嗎?(笑聲)像德古拉伯爵的牙齒,在你身旁人的嘴裡也有嗎?當然沒有。因為我們的牙齒結構實際上的用處,並不是將生肉從骨頭上撕咬下來,或咀嚼滿是纖維的葉片數小時。它適用於一種柔軟、糊狀、纖維少、非常容易咀嚼和消化的飲食,聽起來像是速食,對嗎?

 

(笑聲)

 

它適用於熟食,我們可以看到證明。烹飪、食物的轉化造就我們本身的特質,所以我建議要改變我們對自己的分類。我們說自己是雜食動物,但我說,我們應該稱自己為熟食動物。(笑聲)從煮食到烹飪,我們是吃熟食的動物;不、不、不、不,更貼切的形容是,以熟食為生的動物。因此烹飪是一門非常重要的技術。它確實是門技術,我不知道你們怎麼想,但我喜歡烹飪自娛,而你需要做一些設計才能成功。因此,烹飪是一門非常重要的技術。因為它使我們獲得能讓你到這裡來的東西,就是大腦。我們擁有這個美好的大腦皮質,因為大腦是昂貴的,因此我們現在得付學費。(笑聲)。但它以代謝來說也是昂貴的。我們大腦占體重的 2%-3%,但實際上它使用的總能量占百分之25%,非常昂貴。能量從何而來?當然,來自食物。如果吃生食,我們無法真正釋放能量,因此我們祖先以聰明才智發明這項最美妙的技術。無形的-可以這麼說,我們每個人每天都這麼做。烹飪使得一切變得可能,如基因突變、天擇、我們的環境,也可以使我們得到發展。

 

因此如果我們想想,人類潛能的釋放因烹飪和食物而變得可能,為什麼我們要把某些食物說的那麼糟?為什麼總是有該吃與不該吃、及對你有好處或沒好處的區別?我認為對我來說的好消息是,如果我們能夠回頭來討論關於釋放的議題,人類潛能的持續釋放,烹飪也讓我們成為得以遷徙的物種。我們從非洲遷出兩次,我們的人口散佈在所有生態環境中。如果你會烹飪,就不會發生什麼問題。因為不管你發現什麼,你都將試圖轉變它。它也使你的大腦保持運作。讓這個非常容易和簡單的技術得以發展,就得確實照這個公式進行:(食物 + 烹調 = 能量)。將某樣看起來像食物的東西轉變,它給你一個好的、容易的、方便的能量來源。

 

這個技術影響了兩種器官:大腦和腸道,它確實際造成影響。大腦得以增長,但腸道實際上縮減了。好吧,在我身上這顯然不太明顯。(笑聲)以我的體重來說,靈長類動物的腸道縮小成60%,因為熟食是更容易消化的。有一個大的大腦,如你所知,是一個很大的優勢,因為你可以真正影響你的環境,影響自己所發明的技術;你可以繼續創新和發明,大腦也藉由烹飪而得以如此運作。但它實際上是怎麼運作呢?它實際上是如何參與?以什麼樣的標準?這事實上跟味覺、獎勵和能量有關。你知道,我們有多達五種味覺,其中三個與供應我們營養有關,甜味 - 代表能量;鮮味 - 代表肉的味道,肌肉需要蛋白質用以復元;鹹味-你需要鹽,否則你含電離子的身體不會運作。還有兩種保護你的味覺:苦味和酸味,這是用以對付有毒和腐壞物質;不過,當然,它們很難區分,但我們仍以複雜的方式使用它。想想苦甜巧克力,或想想巧妙混合了莓果的優酪乳酸度。

 

因此我們可以將所有這類東西混合,因為我們知道藉由烹調,我們可以將它轉變成這種形式。獎勵:這種比較複雜,特別是我們大腦的整體構成其中有各種不同的元素,外部狀態、內部狀態、我們如何感覺等等都集合在一起。也許你不喜歡某些東西,但你太餓了,就真的會因為吃而滿足。因此,滿足感是個非常重要的部分。正如我說,能量是必需的。

 

腸道實際上是如何參與這項發展?腸道是一種無聲的聲音,它傾向於以感覺來運作,我委婉的說是消化舒適感,事實上,應該說是消化不適感,這與腸道有關。如果你胃痛,如果你有點發脹,也許是食物不適合,也許是烹調方法不正確,或也許是其他東西出了問題,所以我述說的是一個關於兩個大腦的故事,它可能會讓你大吃一驚。我們的腸道有一個完全成熟的大腦,這演講廳中的你們會說,「你說的不是什麼新玩意兒,我們都知道,直覺嘛(腸道感覺)!(雙關語:gut feeling有直覺之意)我們都有在用啦!」(笑聲)你確實使用它,它事實上是有用的,因為腸道是連接我們的感情邊緣系統,它們確實會彼此交談以作出決定。但有個大腦在那兒,這意味著什麼?意味著不只是那個大的大腦得與食物交談,食物也得與大腦交談,因為我們要學習實際上如何跟這些大腦交談。

 

如果有一個腸道中的大腦,我們也應該學著跟這個大腦交談。150年以前,解剖學家非常、非常小心描繪了-這是一個腸壁的模型,有三個要素:胃、小腸和大腸。在這個結構中,你看到這兩個粉紅色層實際上是肌肉,在肌肉之間發現有神經組織;許多神經組織確實穿透了肌肉,穿透粘膜下層,在那裡有所有免疫系統的組成元素。腸道實際上是保衛你身體最大的免疫系統。它穿透這個黏膜,這一層事實上接觸到你所吞咽和消化的那些食物;這是內腔部分。想想腸道,如果你能將腸道拉開,它會有40米長,相當於一個網球場的長度。如果我們能夠攤開它,將所有折疊處展開,表面積將有400平方米。

 

這個大腦管控它,用肌肉移動它並保護表面。當然,也消化我們烹調的食物。因此,如果給你們一個具體的規格,這個大腦是自主的,有5億個神經細胞、1億個神經元,大小約相當於貓的腦。這裡有個小貓正睡著呢!自我思考、優化它所消化的東西。它有20種不同類型的神經元,它與你在豬腦中所發現有相同的多樣性,那裡1000億個神經元。它具有自主且有組織的微型電路,讓這些程序得以執行。它能感覺食物,它知道該怎麼做,它以化學方法來感覺。非常重要的是,它也運用機械方法,因為它必須移動食物,它必須混合所有各式各樣的元素,那是我們消化所需的。這種肌肉的控制非常、非常重要,因為,你知道,它會產生反射作用。如果你不喜歡某種食物,特別是孩童,就會嘔吐出來,這種反射作用正是這個大腦所產生的。最終它也控制了這個分子機器的分泌作用,這個作用事實上消化了我們所烹飪的食物。

 

這兩個大腦如何互相協作?我以機器人的模式來說明,這就是所謂的包容體系結構。它的意思是,我們有一個分層控制系統,下層是我們的腸道大腦,有自己的目標,即消化防禦;也有上層的大腦,有著整體化的目標並產生行為。兩者都 - 看這個藍箭頭,兩者都作用於相同的食物,食物在內腔中,在腸道的區域。大的大腦整合信號,信號來自於下層大腦正在運行中的程序。但包容體系意味著上層大腦可以干擾下層大腦,它可以取代或抑制信號。因此,如果我們有兩種類型的信號,例如一個饑餓的信號;如果你的胃是空的,就會產生一種叫做饑餓素的荷爾蒙,這是一個非常大的信號,它被傳送到大腦,說「吃東西」。也有停止信號;我們有 8 種停止信號,至少對我來說,它們不聽指揮。(笑聲)

 

會發生什麼情形?如果上層大腦在整合中不理會這個信號?因此,如果不理會饑餓信號就會產生失序,就是所謂的厭食症。儘管產生一個健康的饑餓信號,若大的大腦忽略了它,並在腸道中引發不同的程序,一般情況下多會變成暴飲暴食。它確實採用了這個信號並改變了它,我們將繼續吃,即使我們的八個停止信號會說,「停下來,吃夠了;我們已轉換了足夠的能量。」有趣的是,沿著這個下層大腦,這個腸道信號會越變越強,如果是未消化,但可消化的材料就能滲透,這是我們從減肥手術中發現的;這個信號會非常、非常高。

 

現在回到烹飪還有設計問題。我們已經學會跟上層大腦交談,如你所知,即味覺和獎勵;那要用什麼語言跟腸道大腦交談?它的信號會強大到那個上層大腦無法置之不理嗎?然後我們會產生某種所有人都希望的情況:在饑餓感和飽足感之間

達成平衡。從我們的研究中給你們一個短短的說明。這是脂肪的消化,在你們的左邊有一小滴橄欖油,橄欖油滴受到酶的攻擊。這是體外實驗,要在腸道中進行非常困難。每個人都想知道油滴的分解何時會發生,當這個成分被分解時,它們會消失不見,因為被吸收了。事實上,會出現一個非常複雜的結構,我希望你們能看到影像中間有一些似環狀的結構,那是水,整個系統產生了一個巨大的表面,讓更多的酶攻擊剩餘的油滴。最後在你的右側,從身體將吸收脂肪的地方可以看到一個氣泡狀、似細胞的結構出現。如果我們可以採用這種語言,這是一個結構的語言,並使其更持久,使它可以通過腸道的整段路徑,它會產生更強的信號。

 

因此,我們的研究現在著重於這一點-我想現在大學中也有這樣的研究-我們如何能實際上改變烹飪?在你們來說這可能聽起來微不足道,我們要如何烹飪以使這個語言能夠發展?所以我們事實上擁有的,不是一個雜食動物的困境,而是一個熟食動物的機會,因為我們已經在過去二百萬年學會味道和獎勵是什麼,藉由相當巧妙的烹飪來取悅自己、滿足自己,如果加上這個基質,加上我們必須學習的結構語言,當我們學會它,就可以把它放回去,圍繞著能量,可以產生一個平衡點,這是來自於我們真正的基本操作:烹飪。因此要使烹飪真正成為一個非常重要的因素,我會說,甚至是哲學家都必須改變;我們最終必須瞭解到,烹飪是造就我們特質的東西。

 

所以我要說,「Coquo ergo sum;我烹飪,故我在。」非常感謝。

 

(掌聲)

 

以下為系統擷取之英文原文

About this talk

Did you know you have functioning neurons in your intestines -- about a hundred million of them? Food scientist Heribert Watzke tells us about the "hidden brain" in our gut and the surprising things it makes us feel.

About Heribert Watzke

Heribert Watzke studies the brain in our gut -- and works to develop new kinds of food that will satisfy our bodies and minds. Full bio and more links

Transcript

This technology made a very important impact on us. It changed the way our history developed. But it's a technology so pervasive, so invisible, that we, for a long time, forgot to take it into account when we talked about human evolution. But we see the results of this technology, still. So let's make a little test. So everyone of you turns to their neighbor please. Turn and face your neighbors. Please, also on the balcony. Smile. Smile. Open the mouths. Smile, friendly. (Laughter) Do you -- Do you see any Canine teeth? (Laughter) Count Dracula teeth in the mouths of your neighbors? Of course not. Because our dental anatomy is actually made, not for tearing down raw meat from bones or chewing fibrous leaves for hours. It is made for a diet which is soft, mushy, which is reduced in fibers, which is very easily chewable and digestible. Sounds like fast food, doesn't it.

(Laughter)

It's for cooked food. We carry in our face the proof that cooking, food transformation, made us what we are. So I would suggest that we change how we classify ourselves. We talk about ourselves as omnivores. I would say, we should call ourselves coctivors -- (Laughter) from coquere, to cook. We are the animals who eat cooked food. No, no, no, no. Better -- to live of cooked food. So cooking is a very important technology. It's technology. I don't know how you feel, but I like to cook for entertainment. And you need some design to be successful. So, cooking is a very important technology, because it allowed us to acquire what brought you all here: the big brain, this wonderful cerebral cortex we have. Because brains are expansive. So as we have to pay tuition fees now. (Laughter) But it's also, metabolically speaking, expensive. You now, our brain is two to three percent of the body mass, but actually it uses 25 percent of the total energy we use. It's very expensive. Where does the energy come from. Of course, from food. If we eat raw food, we cannot release really the energy. So this ingenuity of our ancestors, to invent this most marvelous technology. Invisible -- everyone of us does it every day, so to speak. Cooking made it possible that mutations, natural selections, our environment, could develop us.

So if we think about this unleashing human potential, which was possible by cooking and food, why do we talk so badly about food? Why is it always do and don'ts and it's good for you and it's not good for you? I think the good news for me would be if we could go back and talk about the unleashing, the continuation of the unleashing of human potential. Now, cooking allowed also that we became a migrant species. We walked out of Africa two times. We populated all the ecologies. If you can cook, nothing can happen to you, because whatever you find, you will try to transform it. It keeps also your brain working. Now the very easy and simple technology which was developed actually runs after this formula. Take something which looks like food, transform it, and it gives you a good, very easy, accessible energy.

This technology affected two organs, the brain and the gut, which it actually affected. The brain could grow, but the gut actually shrunk. Okay, it's not obvious to be honest. (Laughter) But it shrunk to 60 percent of primate gut of my body mass. So because of having cooked food, it's easier to digest. Now having a large brain, as you know, is a big advantage, because you can actually influence your environment. You can influence your own technologies you have invented. You can continue to innovate and invent. Now the big brain did this also with cooking. But how did it actually run this show? How did it actually interfere? What kind of criteria did it use? And this is actually taste reward and energy. You know we have up to five tastes, three of them sustain us. Sweet -- energy. Umami -- this is a meaty taste. You need proteins for muscles, recovery. Salty, because you need salt, otherwise your electric body will not work. And two tastes which protect you -- bitter and sour, which are against poisonous and rotten material. But of course, they are hard-wired, but we use them still in a sophisticated way. Think about bittersweet chocolate. Or think about the acidity of yogurt -- wonderful -- mixed with strawberry fruits.

So we can make mixtures of all this kind of thing because we know that, in cooking, we can transform it to the form. Reward: this is a more complex and especially integrative form of our brain with various different elements -- the external states, our internal states, how do we feel, and so on are put together. And something which maybe you don't like but you are so hungry that you really will be satisfied to eat. So satisfaction was a very important part. And as I say, energy was necessary.

Now how did the gut actually participate in this development? And the gut is a silent voice. It's going more for feelings. I use the euphemism digestive comfort. Actually, it's a digestive discomfort, which the gut is concerned with. If you get a stomach ache, if you get a little bit bloated, was not the right food, was not the right cooking manipulation, or maybe other things went wrong. So my story is a tale of two brains, because it might surprise you, our gut has a full-fledged brain. All the managers in the room say, "You don't tell me something new, because we know, gut feeling. This is what we are using." (Laughter) And actually you use it, and it's actually useful. Because our gut is connected to our emotional limbic system. They do speak with each other and make decisions. But what it means to have a brain there is that, not only the big brain has to talk with the food, the food has to talk with the brain, because we have to learn actually how to talk to the brains.

Now if there's a gut brain, we should also learn to talk with this brain. Now 150 years ago, anatomists described very, very carefully -- here is a model of a wall of a gut. I took the three elements -- stomach, small intestine and colon. And within this structure, you see these two pinkish layers, which are actually the muscle. And between this muscle, they found nervous tissues, a lot of nervous tissues, which penetrate actually the muscle, penetrate the submucosa, where you have all the elements for the immune system. The gut is actually the largest immune system, defending your body. It penetrates the mucosa. This is the layer which actually touches the food you are swallowing and you digest, which is the lumen. Now if you think about the gut, the gut is, if you could stretch it, 40 meters long, the length of a tennis court. If we could unroll it, get out all the fold and so on, it would have 400 sq. meters of surface.

And now this brain takes care over this, to move it with the muscles and to do defend the surface and, of course, digest our food we cook. So if we give you a specification, this brain, which is autonomous, have 500 million nerve cells, 100 million neurons -- so around the size of a cat brain, so there sleeps a little cat -- thinks for itself, optimizes whatever it digests. It has 20 different neuron types. It's got the same diversity you find actually in a pig brain, where you have 100 billion neurons. It has autonomous organized microcircuits, has these programs which run. It senses the food, it knows exactly what to do. It senses it by chemical means and very importantly by mechanical means, because it has to move the food, it has to mix all the various elements which we need for digestion. This control of muscle is very, very important, because, you know, there can be reflexes. If you don't like a food, especially if you're a child, you gag. It's this brain which makes this reflex. And then finally, it controls also the secretion of this molecular machinery, which actually digests the food we cook.

Now how do the two brains work with each other? I took here a model from robotics. It's called the Subsumption Architecture. What it means is that we have a layered control system. The lower layer, our gut brain, has its own goals -- digestion defense -- and we have the higher brain with the goal of integration and generating behaviors. Now both look -- and this is the blue arrows -- both look to the same food, which is in the lumen and in the area of your intestine. The big brain integrates signals, which come from the running programs of the lower brain, But subsumption means that the higher brain can interfere with the lower. It can replace, or it can inhibit actually, signals. So if we take two types of signals -- a hunger signal for example. If you have an empty stomach, your stomach produces a hormone called ghrelin. It's a very big signal. It's sent to the brain says, "Go and eat." You have stop signals. We have up to eight stop signals. At least in my case, they are not listened to. (Laughter)

So what happens if the big brain in the integration overrides the signal? So if you override the hunger signal, you can have a disorder, which is called anorexia. Despite generating a healthy hunger signal, the big brain ignores it and activates different programs in the gut. The more usual case is overeating. It actually takes the signal and changes it, and we continue, even [though] our eight signals would say, "Stop. Enough. We have transferred enough energy." Now the interesting thing is that, along this lower layer, this gut, the signal becomes stronger and stronger if undigested, but digestible, material could penetrate. This we found from bariatric surgery. That then the signal would be very, very high.

So now back to the cooking question and back to the design. We have learned to talk to the big brain -- taste and reward, as you know. Now what would be the language we have to talk to the gut brain that it's signals are so strong that the big brain cannot ignore it? Then we would generate something all of us would like to have -- a balance between the hunger and the satiation. Now I give you, from our research, a very short claim. This is fat digestion. You have on your left an olive oil droplet, and this olive oil droplet gets attacked by enzymes. This is an in vitro experiment. It's very difficult to work in the intestine. Now everyone would expect that when the degradation of the oil happens, when the constituents are liberated, they disappear, they go away, because they [were] absorbed. Actually, what happens is that a very intricate structure appears. And I hope you can see that there are some ring-like structures in the middle image, which is water. This whole system generates a huge surface to allow more enzymes to attack the remaining oil. And finally, on your right side, you see a bubbly, cell-like structure appearing, from which the body will absorb the fat. Now if we could take this language -- and this is a language of structures -- and make it longer-lasting, that it can go through the passage of the intestine, it would generate stronger signals.

So our research -- and I think the research also at the universities -- are now fixing on these points to say: how can we actually -- and this might sound trivial now to you -- how can we change cooking? How can we cook that we have this language developed? So what we have actually, it's not an omnivore's dilemma. We have a coctivor's opportunity, because we have learned over the last two million years which taste and reward -- quite sophisticated to cook -- to please ourselves, to satisfy ourselves. If we add the matrix, if we add the structure language, which we have to learn, when we learn it, then we can put it back, and around energy, we could generate a balance, which comes out from our really primordial operation: cooking. So, to make cooking really a very important element, I would say even philosophers have to change and have to finally recognize that cooking is what made us.

So I would say, coquo ergo sum: I cook, therefore I am. Thank you very much.

(Applause)
 


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所谓身(肠)心(脑)平衡

Anonymous, 2011-03-29 11:12:04
課程討論
這個概念還蠻新奇呢
aickcese, 2011-01-15 15:10:17
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下载不了
tiptoplsj, 2011-01-02 01:08:44

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