科學(xué)處處有腸道也迷人 中英互譯

Afewyearsago,Ialwayshadthisthinghappeningtome,especiallyatfamilygatheringsliketeaswithauntsandunclesorsomethinglikethis.Whenpeoplecomeuptoyou,andtheyaskyou,“So,whatareyoudoing?”AndIwouldhavethismagicalone-wordreply,whichwouldmakeeverybodyhappy:“Medicine.I’mgoingtobeadoctor.”Veryeasy,that’sit,everybody’shappyandpleased.Anditcouldbesoeasy,butthiseffectreallyonlylastsfor30secondswithme,becausethat’sthenthetimewhenoneofthemwouldask,“So,inwhatareaofmedicine?Whatspecialtydoyouwanttogointo?”AndthenIwouldhavetostripdowninallhonestyandjustsay,“OK,soI’mfascinatedwiththecolon.Itallstartedwiththeanus,andnowit’sbasicallythewholeintestinaltract.”幾年前，我一直碰到這件事，特別是在家庭聚會(huì)時(shí)，比如和姑姑阿姨叔叔舅舅喝茶時(shí)。他們會(huì)過(guò)來(lái)問(wèn)我：“你在學(xué)什么？”而我的回復(fù)是一個(gè)奇妙的詞，這個(gè)回復(fù)會(huì)讓每個(gè)人都開(kāi)心：“我學(xué)醫(yī)，將來(lái)要當(dāng)醫(yī)生?！狈浅：?jiǎn)單，就這樣，大家都開(kāi)心愉快。雖然很容易，但這個(gè)效應(yīng)對(duì)我來(lái)說(shuō)其實(shí)只會(huì)持續(xù)30秒，因?yàn)榻又蜁?huì)有人發(fā)問(wèn)：“那你學(xué)的是醫(yī)學(xué)的哪個(gè)領(lǐng)域？想專攻哪方面？”于是，我就得很坦誠(chéng)地回答：“喔，我喜歡研究結(jié)腸，它從肛門(mén)開(kāi)始，基本上就是整個(gè)腸道?！盇ndthiswouldbethemomentwhentheenthusiasmtrickled,anditwouldmaybealsoget,like,awkwardlysilentintheroom,andIwouldthinkthiswasterriblysad,becauseIdobelieveourbowelsarequitecharming.就在這時(shí)，熱情開(kāi)始消退，也許房間里還會(huì)出現(xiàn)尷尬的沉默，我會(huì)覺(jué)得這太糟糕了，因?yàn)槲艺嫘挠X(jué)得我們的腸子相當(dāng)迷人。

Andwhilewe’reinatimewheremanypeoplearethinkingaboutwhatnewsuperfoodsmoothietomakeorifglutenismaybebadforthem,actually,hardlyanyoneseemstocareabouttheorganwherethishappens,theconcreteanatomyandthemechanismsbehindit.Andsometimesitseemstomelikewe’realltryingtofigureoutthismagictrick,butnobody'scheckingoutthemagician,justbecausehehas,like,anembarrassinghairstyleorsomething.Andactually,therearereasonssciencedislikedthegutforalongtime;Ihavetosaythis.雖然在這個(gè)時(shí)代，許多人會(huì)想做什么超級(jí)食物奶昔，或者考慮麩質(zhì)是否對(duì)身體有害，但事實(shí)上，似乎很少有人會(huì)在乎承擔(dān)這些活動(dòng)的身體器官、具體的解剖學(xué)及其背后的機(jī)制。有時(shí)，在我看來(lái)，就像我們都在試著看穿這個(gè)魔術(shù)，卻沒(méi)有人去看魔術(shù)師，只因?yàn)樗l(fā)型令人尷尬或諸如此類的原因。其實(shí)，科學(xué)界長(zhǎng)期以來(lái)不喜歡腸道的原因很多，我不得不這么說(shuō)。

So,it’scomplex.There’salotofsurfacearea—about40timestheareaofourskin.Then,insuchatightpipe,therearesomanyimmunecellsthatarebeingtrainedthere.Wehave100trillionbacteriadoingallsortsofthings—producinglittlemolecules.Thenthere’sabout20differenthormones,soweareonaverydifferentlevelthanourgenitals,forexample.Andthenervoussystemofourgutissocomplexthatwhenwecutoutapiece,it’sindependentenoughthatwhenwepokeit,itmumblesbackatus,friendly.它很復(fù)雜。它有巨大的表面積，差不多是皮膚表面積的40倍。在如此緊密的管道中，有非常多的免疫細(xì)胞在受訓(xùn)。有100兆細(xì)菌在做各種事情——產(chǎn)生小分子。還有大約20種不同的荷爾蒙，所以，例如和生殖器相比，我們所處的層級(jí)很不一樣。而腸子的神經(jīng)系統(tǒng)非常復(fù)雜，當(dāng)我們切下一小片，它是獨(dú)立的，當(dāng)我們戳它，它會(huì)友善地咕噥著回應(yīng)我們。

Butatleastthosereasonsarealsothereasonswhyit’ssofascinatingandimportant.但至少，那些理由也是它如此迷人且重要的原因。

Ittookmethreestepstolovethegut.Sotoday,Iinviteyoutofollowmeonthosethreesteps.Theveryfirstwasjustlookingatitandaskingquestionslike,“Howdoesitwork?”and“Whydoesithavetolooksoweirdforthatsometimes?”Anditactuallywasn’tmeaskingthefirstkindofthesequestions,butmyroommate.Afteroneheavynightofpartying,hecameintoourshared-roomkitchen,andhesaid,“Giulia,youstudymedicine.Howdoespoopingwork?”我經(jīng)過(guò)三個(gè)步驟愛(ài)上了腸子。今天，我邀請(qǐng)各位跟我一起回顧這三步。第一步就是看著它，然后問(wèn)這樣的問(wèn)題：“它如何運(yùn)作？”及“為什么它有時(shí)看上去如此怪異？”。其實(shí)并不是我先問(wèn)出這樣的問(wèn)題的，而是我的室友。一天晚上，狂歡聚會(huì)之后，他來(lái)到我們共享的廚房，說(shuō)：“朱莉亞，你是讀醫(yī)的。拉屎是怎么回事？”

AndIdidstudymedicinebutIhadnoidea,soIhadtogouptomyroomandlookitupindifferentbooks.AndIfoundsomethinginteresting,Ithought,atthattime.Soitturnsout,wedon’tonlyhavethisoutersphincter,wealsohaveaninnersphinctermuscle.Theoutersphincterweallknow,wecancontrolit,weknowwhat’sgoingonthere;theinnerone,wereallydon’t.Sowhathappensis,whenthereareleftoversfromdigestion,they’rebeingdeliveredtotheinneronefirst.Thisinneronewillopeninareflexandletthroughalittlebitfortesting.我的確讀醫(yī)，但我不知道答案，于是我回房查不同的書(shū)。那時(shí)，我認(rèn)為自己發(fā)現(xiàn)了有趣的東西。結(jié)果是，我們不只有這個(gè)外括約肌，我們還有內(nèi)括約肌。我們都知道外括約肌，我們可以控制它，我們知道那里的狀況；內(nèi)括約肌，我們就不了解了。過(guò)程是這樣的：當(dāng)消化之后還有殘余物，它們會(huì)先被運(yùn)送到內(nèi)括約肌。內(nèi)括約肌會(huì)反射性地打開(kāi)，讓一點(diǎn)點(diǎn)殘余物通過(guò)，做測(cè)試。So,therearesensorycellsthatwillanalyzewhathasbeendelivered:Isitgaseousorisitsolid?Andtheywillthensendthisinformationuptoourbrain,andthisisthemomentwhenourbrainknows,“Oh,Ihavetogotothetoilet.”那里有感覺(jué)細(xì)胞，會(huì)分析運(yùn)送來(lái)的是什么：氣體還是固體？接著，這信息會(huì)被送到大腦，這時(shí)，我們的大腦就會(huì)知道：“喔，我得去上廁所?！?/p>

Thebrainwillthendowhatit’sdesignedtodowithitsamazingconsciousness.Itwillmediatewithoursurroundings,anditwillsaysomethinglike,“So,Ichecked.WeareatthisTEDxconference—”大腦接著就會(huì)用它不可思議的意識(shí)著手做它該做的事。它會(huì)在我們和環(huán)境之間調(diào)停，比如說(shuō)：“我確認(rèn)了。我們正在TEDx會(huì)議上——”

Gaseous?Maybe,ifyou'resittingonthesides,andyouknowyoucanpullitoffsilently.氣體？也許可以，如果你坐在邊上，你就知道你可以悄悄地釋放掉。

Butsolid—maybelater.但固體——也許晚點(diǎn)再說(shuō)吧。

Sinceouroutersphincterandthebrainisconnectedwithnervouscells,theycoordinate,cooperate,andtheyputitbackinawaitingline—forothertimes,like,forexample,whenwe'reathomesittingonthecouch,wehavenothingbettertodo,wearefreetogo.因?yàn)槲覀兊耐饫s肌和頭腦是通過(guò)神經(jīng)細(xì)胞連結(jié)的，它們互相協(xié)調(diào)、合作，會(huì)把固體推回，讓其等候——在其他時(shí)間釋放，比如，當(dāng)我們?cè)诩易谏嘲l(fā)上的時(shí)候，沒(méi)別的事要做，我們就可以自由釋放了。

Ushumansareactuallyoneoftheveryfewanimalsthatdothisinsuchanadvancedandcleanway.Tobehonest,Ihadsomenewfoundrespectforthatnice,innersphincterdude—notconnectedtonervesthatcaretoomuchabouttheouterworldorthetime—justcaringaboutmeforonce.Ithoughtthatwasnice.AndIusedtonotbeagreatfanofpublicrestrooms,butnowIcangoanywhere,becauseIconsideritmorewhenthatinnermuscleputsasuggestiononmydailyagenda.沒(méi)有幾種動(dòng)物能夠以如此高級(jí)且干凈的方式排便，我們?nèi)祟愂瞧渲兄?。老?shí)說(shuō)，我對(duì)于這位出色的內(nèi)括約肌同志增添了新的敬意——它沒(méi)有和神經(jīng)連結(jié)，而神經(jīng)太在乎外在世界或時(shí)間了——多么難得，它獨(dú)獨(dú)關(guān)心我。我覺(jué)得這真好。我以前對(duì)公共廁所敬謝不敏，但現(xiàn)在在哪兒都可以了，因?yàn)楫?dāng)內(nèi)括約肌在我的每天的日程中提出一條建議時(shí)，我會(huì)多多體貼它一下。AndalsoIlearnedsomethingelse,whichwas:lookingcloselyatsomethingImighthaveshiedawayfrom—maybetheweirdestpartofmyself—leftmefeelingmorefearless,andalsoappreciatingmyselfmore.AndIthinkthishappensalotoftimeswhenyoulookatthegut,actually.Likethosefunnyrumblingnoisesthathappenwhenyou’reinagroupoffriendsorattheofficeconferencetable,going,like,“Merrr,merrr...”Thisisnotbecausewe’rehungry.Thisisbecauseoursmallintestineisactuallyahugeneatfreak,andittakesthetimeinbetweendigestiontocleaneverythingup,resultinginthoseeightmetersofgut—really,sevenofthem—beingverycleanandhardlysmellinglikeanything.Itwill,toachievethis,createastrongmuscularwavethatmoveseverythingforwardthat’sbeenleftoverafterdigestion.Thiscansometimescreateasound,butdoesn'tnecessarilyhavetoalways.Sowhatwe’reembarrassedofisreallyasignofsomethingkeepingourinsidesfineandtidy.我還學(xué)到了其他東西：仔細(xì)觀察某樣我之前可能羞于面對(duì)的東西——也許是我身體最怪異的部分——會(huì)讓我覺(jué)得更無(wú)懼，也更懂得欣賞我自己。我認(rèn)為，這種情況其實(shí)常常會(huì)發(fā)生，就在你看著腸子的時(shí)候。比如當(dāng)你剛好和一群朋友在一起或在辦公室開(kāi)會(huì)時(shí)，它發(fā)出好笑的咕嚕聲“么么么……”。這并不是因?yàn)槲覀凁I了。這是因?yàn)槲覀兊男∧c其實(shí)是個(gè)很愛(ài)干凈的怪胎，它會(huì)在兩次消化之間的空檔進(jìn)行大掃除，導(dǎo)致那8米的腸子——其實(shí)是其中7米——變得非常干凈，幾乎沒(méi)有任何味道。為了做到這一點(diǎn)，它會(huì)產(chǎn)生強(qiáng)力的肌肉抖動(dòng)，把消化后的殘余物通通向前推。有時(shí)候這會(huì)發(fā)出聲音，但并非一定如此。所以，這讓我們感到尷尬的聲音其實(shí)是個(gè)征兆，表示有某樣?xùn)|西在保持我們內(nèi)部的健康和清潔。Orthisweird,crookedshapeofourstomach—abitQuasimodo-ish.Thisactuallymakesusbeabletoputpressureonourbellywithoutvomiting,likewhenwe’relaughingandwhenwe’redoingsports,becausethepressurewillgoupandnotsomuchsideways.Thisalsocreatesthisairbubblethat’susuallyalwaysveryvisibleinX-rays,forexample,andcansometimes,withsomepeople,whenitgetstoobig,creatediscomfortorevensomesensationsofpain.Butformostofthepeople,isjustresultsthatit’sfareasiertoburpwhenyou’relayingonyourleftsideinsteadofyourright.我們胃部這個(gè)怪異彎曲的形狀有點(diǎn)像“鐘樓怪人”。這其實(shí)讓我們能夠?qū)ψ约旱母共考訅?，且不?huì)造成嘔吐，比如當(dāng)我們大笑、做運(yùn)動(dòng)時(shí)，因?yàn)閴毫?huì)向上，而不會(huì)偏向兩邊。這個(gè)過(guò)程還會(huì)產(chǎn)生氣泡，例如，在X光下可以看得很清楚，有時(shí)候有些人的氣泡會(huì)太大，就會(huì)造成不適，甚至有痛的感覺(jué)。但對(duì)大多數(shù)人來(lái)說(shuō)，最多可能就是，當(dāng)你左側(cè)臥時(shí)，會(huì)比右側(cè)臥更容易打嗝。

AndsoonImovedabitfurtherandstartedtolookatthewholepictureofourbodyandhealth.ThiswasactuallyafterIhadheardthatsomeoneIknewalittlebithadkilledhimself.IthappenedthatIhadbeensittingnexttothatpersonthedaybefore,andIsmelledthathehadverybadbreath.AndwhenIlearnedofthesuicidethenextday,Ithought:Couldtheguthavesomethingtodowithit?AndIfranticallystartedsearchingiftherewerescientificpapersontheconnectionofgutandbrain.Andtomysurprise,Ifoundmany.不久后，我更進(jìn)了一步，開(kāi)始觀察我們的整個(gè)身體以及健康狀況。這其實(shí)是在我聽(tīng)說(shuō)某個(gè)我認(rèn)識(shí)的人自殺之后的事，剛好前一天我曾坐在那個(gè)人旁邊，我聞到他有嚴(yán)重的口臭。當(dāng)我知道他第二天自殺了時(shí)，我心想：有沒(méi)有可能和腸子有關(guān)？我開(kāi)始瘋狂地尋找涉及腸子與大腦間關(guān)聯(lián)的科學(xué)文獻(xiàn)。讓我驚訝的是，我找到很多。

Itturnsoutit’smaybenotassimpleaswesometimesthink.Wetendtothinkourbrainmakesthesecommandsandthensendsthemdowntotheotherorgans,andtheyallhavetolisten.Butreally,it’smorethat10percentofthenervesthatconnectbrainandgutdeliverinformationfromthebraintothegut.Weknowthis,forexample,instressfulsituations,whentherearetransmittersfromthebrainthatarebeingsensedbyourgut,sothegutwilltrytolowerallthework,andnotbeworkingandtakingawaybloodandenergytosaveenergyforproblem-solving.Thiscangoasfarasnervousvomitingornervousdiarrheatogetridoffoodthatitthendoesn'twanttodigest.我發(fā)現(xiàn)，事實(shí)或許并非我們想得那么簡(jiǎn)單。我們通常認(rèn)為，大腦會(huì)下指令，然后把指令送到其他器官，它們都得聽(tīng)命。但實(shí)際上，更多情況下，10%連結(jié)大腦和腸子的神經(jīng)會(huì)把信息從大腦傳到腸子。我們知道，比如在有壓力的狀態(tài)下，我們的腸子感知到來(lái)自大腦的神經(jīng)遞質(zhì)后，就會(huì)試著減緩所有工作，不再工作，也不再消耗太多血液和能量，以儲(chǔ)存能量解決問(wèn)題。這可能表現(xiàn)為神經(jīng)性嘔吐或神經(jīng)性腹瀉，目的是要擺脫不想消化的食物。

Maybemoreinterestingly,90percentofthenervousfibersthatconnectgutandbraindeliverinformationfromourguttoourbrain.Andwhenyouthinkaboutitalittlebit,itdoesmakesense,becauseourbrainisveryisolated.It’sinthisbonyskullsurroundedbyathickskin,anditneedsinformationtoputtogetherafeelingof“HowamI,asawholebody,doing?”Andthegut,actually,ispossiblythemostimportantadvisorforthebrainbecauseit’sourlargestsensoryorgan,collectinginformationnotonlyonthequalityofournutrients,butreallyalsoonhowaresomanyofourimmunecellsdoing,orthingslikethehormonesinourbloodthatitcansense.Anditcanpackagethisinformation,andsendituptothebrain.Itcan,there,notreachareaslikevisualcortexorwordformations—otherwise,whenwedigest,wewouldseefunnycolorsorwewouldmakefunnynoises—no.Butitcanreachareasforthingslikemorality,fearoremotionalprocessingorareasforself-awareness.可能更有趣的是，90%連結(jié)腸子和大腦的神經(jīng)纖維會(huì)把信息從我們的腸子傳送給大腦。稍微想想，的確是這樣，因?yàn)槲覀兊拇竽X是很孤立的。它位于厚皮包裹的頭骨內(nèi)，需要信息才能整合體驗(yàn)“我整個(gè)身體狀況如何？”。而腸子實(shí)際上可能就是大腦最重要的顧問(wèn)，因?yàn)樗俏覀冏畲蟮母杏X(jué)器官，收集的信息不只是我們吸收營(yíng)養(yǎng)的好壞，還包括這么多免疫細(xì)胞狀況如何，或它能感受到的我們血液中的荷爾蒙的情況。它能把這些信息打包送到大腦去。而它不會(huì)到大腦中像是視覺(jué)皮質(zhì)或是言語(yǔ)形成的區(qū)域，否則當(dāng)我們消化時(shí)就會(huì)看到奇怪的顏色或發(fā)出奇怪的聲音——而我們不會(huì)。但它會(huì)到包括道德、恐懼、情緒處理或自我意識(shí)的區(qū)域。

Soitdoesmakesensethatwhenourbodyandourbrainareputtingtogetherthisfeelingof,“HowamI,asawholebody,doing?”thattheguthassomethingtocontributetothisprocess.Anditalsomakessensethatpeoplewhohaveconditionslikeirritablebowelsyndromeorinflammatoryboweldiseasehaveahigherriskofhavinganxietyordepression.Ithinkthisisgoodinformationtoshare,becausemanypeoplewillthink,“Ihavethisgutthing,andmaybeIalsohavethismentalhealththing.”Andmaybe—becausescienceisnotclearonthatrightnow—it’sreallyjustthatthebrainisfeelingsympathywiththeirgut.所以，確實(shí)，當(dāng)我們的身體和大腦整合體驗(yàn)“我整個(gè)身體狀況如何”時(shí)，腸子對(duì)于這個(gè)過(guò)程做出了一定的貢獻(xiàn)。還有一點(diǎn)很有道理，人們?nèi)绻忌洗竽c激躁癥或發(fā)炎性腸道疾病之類的疾病，他們得焦慮癥或抑郁癥的風(fēng)險(xiǎn)也會(huì)比較高。我認(rèn)為這個(gè)信息很有用，值得分享，因?yàn)樵S多人會(huì)想到：“如果我的腸子有問(wèn)題，也許我的心理健康也有問(wèn)題?！币苍S——因?yàn)榭茖W(xué)目前尚不能清楚解釋這一點(diǎn)——也許只是大腦在同情腸子。

Thishasyettogrowinevidenceuntilitcancometopractice.Butjustknowingaboutthesekindsofresearchthat'soutthereatthemomenthelpsmeinmydailylife.Anditmakesmethinkdifferentlyofmymoodsandnotexternalizesomuchallthetime.Ifeeloftentimesduringthedayweareabrainandascreen,andwewilltendtolookforanswersrightthereandmaybetheworkisstupidorourneighbor—butreally,moodscanalsocomefromwithin.Andjustknowingthishelpedme,forexample,whenIsometimeswakeuptooearly,andIstarttoworryandwanderaroundwithmythoughts.ThenIthink,“Stop.WhatdidIeatyesterday?DidIstressmyselfouttoomuch?DidIeattoolateorsomething?”Andthenmaybegetupandmakemyselfatea,somethinglighttodigest.Andassimpleasthatsounds,Ithinkit’sbeensurprisinglygoodforme.這方面還需要更多證據(jù)才能付諸實(shí)踐。但是僅僅知道這一類研究正在某處進(jìn)行，就對(duì)我的日常生活很有幫助了。它讓我對(duì)自己的心情有不同的看法，不再把很多事情都?xì)w為外因。我常常覺(jué)得，白天我們就像是一個(gè)大腦加上一塊屏幕，往往會(huì)向外界尋找情緒的根源，也許歸咎于愚蠢的工作或鄰里關(guān)系，但其實(shí)情緒也可能是內(nèi)在造成的。光是知道這點(diǎn)就對(duì)我很有幫助了，比如，有時(shí)我太早醒來(lái)，會(huì)開(kāi)始擔(dān)心并胡思亂想。這時(shí)我就會(huì)想：“停。我昨天吃了什么？我讓自己太過(guò)焦慮了吧？我是不是吃得太晚了什么的？”接著，我也許會(huì)起床給自己泡壺茶，弄點(diǎn)兒好消化的清淡東西。這聽(tīng)起來(lái)很簡(jiǎn)單，對(duì)我非常有用。

Stepthreetookmefurtherawayfromourbody,andtoreallyunderstandingbacteriadifferently.Theresearchwehavetodayiscreatinganewdefinitionofwhatrealcleanlinessis.Andit’snotthehygienehypothesis—Ithinkmanymaybeknowthis.Soitstatesthatwhenyouhavetoolittlemicrobesinyourenvironmentbecauseyoucleanallthetime,that’snotreallyagoodthing,becausepeoplegetmoreallergiesorautoimmunediseasesthen.SoIknewthishypothesis,andIthoughtIwouldn’tlearnsomuchfromlookingatcleanlinessinthegut.ButIwaswrong.第三步讓我從我們的身體出發(fā)走向更遠(yuǎn)，真正對(duì)細(xì)菌有了不同的理解。我們現(xiàn)今的研究對(duì)于真正的干凈下了新的定義。不是衛(wèi)生假說(shuō)，我想很多人可能知道這假說(shuō)。它說(shuō)的是，當(dāng)因?yàn)槟汶S時(shí)清理而造成環(huán)境中微生物過(guò)少時(shí)，那其實(shí)并不是好事，因?yàn)槿藗儠?huì)因此更容易過(guò)敏或患上自體免疫疾病。我知道這個(gè)假說(shuō)，我以為只著眼于腸子內(nèi)的清潔衛(wèi)生是不會(huì)學(xué)到這么多東西的。但我錯(cuò)了。

Itturnsout,realcleanlinessisnotaboutkillingoffbacteriarightaway.Realcleanlinessisabitdifferent.Whenwelookatthefacts,95percentofallbacteriaonthisplanetdon’tharmus—theycan’t,theydon’thavethegenestodoso.Many,actually,helpusalot,andscientistsatthemomentarelookingintothingslike:Dosomebacteriahelpuscleanthegut?Dotheyhelpusdigest?Dotheymakeusputonweightorhavealeanfigurealthoughwe’reeatinglots?Areothersmakingusfeelmorecourageousorevenmoreresilienttostress?Soyousee,therearemorequestionswhenitcomestocleanliness.And,actually,thethingis,it’saboutahealthybalance,Ithink.Youcan’tavoidthebadallthetime.Thisissimplynotpossible;there’salwayssomethingbadaround.Sowhatreallythewholedealiswhenyoulookatacleangut,it’sabouthavinggoodbacteria,enoughofthem,andthensomebad.Ourimmunesystemneedsthebad,too,soitknowswhatit’slookingoutfor.其實(shí)，真正的清潔并不是要把細(xì)菌殺光。真正的清潔有點(diǎn)兒不同。我們來(lái)看看事實(shí)，地球上95%