经济学人282:心脏疾病与微生物

 　　Science and technology

　　科学技术

　　Heart disease and the microbiome

　　心脏疾病与微生物

　　High steaks

　　牛排吃越多，心脏病风险越高

　　Hardening of the arteries¹ may be caused by a malign² interaction of meat-eating and intestinal³ bacteria

　　肉食与肠道细菌的恶性作用可能会造成动脉硬化

　　THOSE who take part in clinical trials often have to do nasty things, from taking new drugs to forgoing⁴ sleep.

　　参加临床试验的受试者常常得要做一些令人难受的事儿，从试用新药到放弃睡眠。

　　Participants in a trial organised by Stanley Hazen of the Cleveland Clinic, in Ohio, had a decidedly easier task: eating steak.

　　克里夫兰医学中心的斯坦利?哈森在俄亥俄州组织的临床试验中的受试者所要做的，相对来说要简单的多：吃牛排。

　　After reading Dr Hazen's conclusions, though, they may be inclined to eat rather less of it.

　　但要是读过哈森博士的实验报告后，他们或许宁愿自己少吃一些。

　　A link between red-meat consumption and heart disease was perceived by epidemiologists several decades ago, but the nature of this link has never been properly explained.

　　几十年前就有流行病学家发现心脏疾病与食用红肉有关，但这种关联的原理一直没有得到合理的解释。

　　Blame's finger usually points at saturated⁵ fats and cholesterol⁶.

　　饱和脂肪酸和胆固醇经常被指责为引起心脏疾病的罪魁祸首。

　　Red meat contains both.

　　红肉中这两种物质都有。

　　But a big recent study showed no connection between saturated fat and heart disease, so something else is probably involved.

　　最近一项大型研究发现饱和脂肪酸并不会引起心脏疾病，很可能是一些其他物质引起的心脏疾病。

　　Dr Hazen thinks he knows what.

　　哈森博士认为他发现了这些物质是什么。

　　As he outlines in a paper just published in Nature Medicine, he believes the blame actually lies with the microbiome—the collection of 100 trillion or so bacteria that live in the human gut⁷.

　　正如他在《自然医学》上刚发表的文章中所说的那样，他认为罪魁祸首实际上是微生物菌群-人体肠道中生存着大约100万亿细菌。

　　Generally, members of the microbiome get on well with their host.

　　一般来说，肠道菌群可与宿主和谐共处。

　　They digest complex carbohydrates⁸ that human enzymes⁹ cannot handle, thus increasing the nutritional¹⁰ value of food.

　　它们可分解人体中的酶所不能分解的复杂碳水化合物，因而可进一步提高食物的营养价值。

　　They also fend¹¹ off infections by hostile bugs¹².

　　它们还可阻挡病原菌对人体的侵害。

　　But, as with any partnership¹³, the interests of the partners are not always in perfect alignment¹⁴, and Dr Hazen thinks the processing of red meat is an example of such misalignment.

　　不过，像任何合作关系一样，双方的利益并不总是完美一致的，哈森博士认为红肉的消化吸收过程正是这种不一致的实例。

　　The mismatch in question revolves¹⁵ around a molecule¹⁶ called carnitine.

　　这种失衡主要是由一种叫做肉毒碱的化学物质引起的。

　　This chemical helps transport fatty acids inside cells, and red meat is rich in it.

　　肉毒碱可参与运输细胞内的脂肪酸，而红肉中富含肉毒碱。

　　Dr Hazen thinks that when it is metabolised by gut bacteria, a chain of events begins that results in atherosclerosis.

　　哈森博士认为肠道细菌代谢红肉时，由此引发人体内一连串的生物化学反应，从而导致动脉粥样硬化。

　　A gut feeling

　　肠道感觉

　　Dr Hazen has already demonstrated, in a paper published in 2011, that parts of the microbiome can promote atherosclerosis.

　　哈森博士在他2011年发表的文章中验证，部分肠道菌群可促进动脉硬化。

　　In that paper he showed that choline, a molecule found in eggs and meat, is digested by some gut bacteria to produce trimethylamine, which is then processed in the liver to create trimethylamine N-oxide, or TMAO—a substance that encourages atherosclerosis.

　　他在文中指出胆碱—在蛋类和肉类中发现的一种分子，被肠道细菌消化吸收后生成三甲胺，三甲胺在肝脏中转化为能够加速动脉硬化的三甲胺N-氧化物或氧化三甲胺。

　　That is bad in general.

　　这些化学物质通常对人体是有害的。

　　And if the arteries in question are the coronary arteries, which supply heart muscle with blood, it is bad in particular because it can lead to a heart attack.

　　并且如果有损伤的动脉是为心肌供血的冠状动脉，情况尤为糟糕，因为这将引起心脏病发作。

　　Carnitine is chemically similar to choline so, given its abundance in red meat, Dr Hazen wanted to know if it, too, might be linked with heart disease.

　　肉毒碱的化学作用与胆碱相似，由于肉毒碱在红肉中含量丰富，哈森博士试图通过实验探究肉毒碱是否也与心脏疾病有关联。

　　He also wanted to know how TMAO wreaks¹⁷ its havoc¹⁸ on arteries.

　　同时他也想搞清楚氧化三甲胺是如何损伤动脉血管的。

　　Attempting to answer these questions required several studies, on both mice and men.

　　为了得到答案，哈森博士对人和老鼠进行了多项研究。

　　The first involved five human volunteers eating 8oz sirloin steaks, plus a carnitine supplement.

　　第一组实验的五个志愿者食用了8盎司沙朗牛排以及一片肉毒碱补充剂。

　　This diet resulted in high levels of both carnitine and TMAO in the volunteers' blood.

　　实验结果是，志愿者血液中都出现了高含量的肉毒碱和氧化三甲胺。

　　But when the same people were given antibiotics¹⁹ to kill their gut microbes, a subsequent steak meal produced little TMAO, even though their carnitine levels went even higher than before.

　　但当这些志愿者食用可杀死肠道细菌的抗生素后，食用同样的牛排却只产生了少量的氧化三甲胺，尽管之前他们血液中肉毒碱含量升高过。

　　Production of TMAO, then, seems to need bacteria.

　　这表明氧化三甲胺的产生似乎确实需要肠道菌群参与。

　　Those bacteria are not, however, always present.

　　然而，这样的肠道细菌并不总是存在的。

　　In the interests of science, Dr Hazen persuaded a vegan volunteer to eat a steak.

　　出于对科学真理的探索，哈森博士说服一名严格素食主义志愿者食用一块牛排。

　　He compared this man's subsequent TMAO levels with those of a meat eater after a steak meal.

　　他将这位志愿者与食肉志愿者吃牛排后的血液中氧化三甲胺含量相比较，

　　The carnivore's TMAO levels jumped.

　　肉食志愿者的氧化三甲胺含量飙升，

　　The vegan's did not.

　　而素食志愿者的却没有。

　　That suggests the vegan's particular gut flora—adapted to his usual meat-free diet—did not contain species that can digest carnitine.

　　这表明素食者特有的肠道菌群—已经适应了他日常的素食饮食—不含可分解肉毒碱的细菌。

　　Some vegetarian²⁰ volunteers, given carnitine pills but spared the steak, showed similar results.

　　一些素食志愿者没吃牛排，但服用肉毒碱制剂，实验结果与吃牛排相似。

　　To find out whether all this matters, Dr Hazen looked at the association between heart disease and levels of carnitine and TMAO in more than 2,500 people.

　　为证实所有这些因素是否相关，哈森博士调查了2500多人，试图发现心脏疾病与肉毒碱和氧化三甲胺之间的关系。

　　He found there was indeed an association between heart disease and carnitine, but only when TMAO levels were also high.

　　他发现心脏疾病确实与肉毒碱的含量有关，但只有当氧化三甲苯含量也同样很高时才可以。

　　Experiments in mice confirmed the broader hypothesis: TMAO production relies on microbes that digest carnitine, and prolonged consumption of that chemical by susceptible²¹ mice leads to atherosclerosis.

　　老鼠实验证实了进一步的猜想：氧化三甲胺的产生需要分解肉毒碱的肠道细菌参与，易感小鼠如果长期食用肉毒碱会导致动脉硬化。

　　Exactly how this happens is still hazy²².

　　确切的作用机理目前尚不清楚。

　　Dr Hazen has shown, in yet further experiments on mice,that microbe-generated TMAO interferes²³ with liver enzymes that make bile acids—substances that help remove excess cholesterol.

　　在接下来的老鼠实验中，哈森博士指出，细菌分解产生的氧化三甲胺可干扰产生胆汁酸的肝酶的活性—胆汁酸可帮助转移多余的胆固醇。

　　TMAO also influences cholesterol metabolism²⁴ in other parts of the body, including the artery²⁵ wall.

　　氧化三甲胺还影响包括动脉壁在内的身体其他部位中的胆固醇代谢。

　　But the precise chain of events linking microbes to heart disease is still unclear.

　　但使得肠道细菌与心脏疾病有关的一系列相关的精确反应至今还不清楚。

　　Another unknown is which of the microbiome's many species are responsible for promoting TMAO production.

　　肠道菌群中是否有很多种细菌参与氧化三甲胺的生成目前也并不明确。

　　Based on an analysis of the faeces of both vegetarians²⁶ and meat eaters, Dr Hazen suspects bacteria of several genera, including Clostridium and Fusibacterium.

　　基于对素食与肉食志愿者的粪便研究，哈森博士猜想有几种不同属的细菌参与反应，其中包括梭状芽胞杆菌属和梭菌属。

　　Regardless of the details, though, this study suggests that people looking for the link between heart disease and the eating of meat have been ignoring two culprits, carnitine and bacteria.

　　但不论生化反应细节如何，这项研究表明人们长期以来寻找心脏病与食肉之间的关联，却忽略了肉毒碱和肠道细菌这两大元凶。

　　That does not absolve²⁷ cholesterol of blame—on the contrary, carnitine boosts cholesterol's pernicious effect.

　　不过这并不意味着胆固醇是无害的—相反，肉毒碱的存在大大增长了胆固醇的害处。

　　But the study is yet another reminder²⁸ that medical science's past failure to take proper account of humanity's bacterial²⁹ guests has stopped researchers understanding how bodies actually work.

　　这项研究同时也提醒人们，之前医学研究未能把人体肠道内的细菌考虑在内，使得研究者们没能真正搞明白人体是如何运转的。

　　Heart disease is the biggest killer³⁰ around.

　　现在心脏疾病是威胁人类健康的头号杀手。

　　Though Dr Hazen's analysis does not change advice about how to prevent atherosclerosis, it may radically³¹ revise the treatment of those for whom prevention has failed.

　　虽然哈森博士的研究未能改变预防动脉硬化的医嘱，但却彻底改变了动脉硬化患者的治疗方案。

　　1.incline to 向…方向弯， 倾斜

　　Spin industry foreign trader invests motive³² and incline to analysis.

　　纺织行业外商投资动机与趋向分析。

　　I incline to disagree with you on that point.

　　在那一点上我倾向于跟你意见不同。

　　2.publish in 发表于

　　The second main kind of blogs are, in effect, niche³³ magazines that choose to publish in a blog format³⁴.

　　另一类博客，实际上是以博客形式发布的非主流杂志。

　　In recent years, of course, the pressure on scientists to publish in the top journals has increased, making the journals that much more crucial to career success.

　　当然，近年来要求科技工作者在顶级期刊上发表论文的压力越来越大，使得这些期刊在他们事业成功上所起的作用越来越关键。

　　3.live in 住在；存在于

　　My friends jenny and danny live in canada.

　　我的朋友詹妮和丹尼住在加拿大。

　　In what world do you live in?

　　你生活在一个什么样的世界？

　　4.lead to 通向；导致

　　That can lead to serious consequences.

　　这会导致严重的后果。

　　All these ideologies³⁵ lead to repression³⁶.

　　所有这些思想最终都导致镇压。

1 arteries   

n.动脉( artery的名词复数 )；干线，要道

参考例句：

• Even grafting new blood vessels in place of the diseased coronary arteries has been tried. 甚至移植新血管代替不健康的冠状动脉的方法都已经试过。 来自《简明英汉词典》
• This is the place where the three main arteries of West London traffic met. 这就是伦敦西部三条主要交通干线的交汇处。 来自《简明英汉词典》

2 malign   

adj.有害的；恶性的；恶意的；v.诽谤，诬蔑

参考例句：

• It was easy to see why the cartoonists regularly portrayed him as a malign cherub.难怪漫画家总是把他画成一个邪恶的小天使。
• She likes to malign innocent persons.她爱诋毁那些清白的人。

3 intestinal   

adj.肠的；肠壁；肠道细菌

参考例句：

• A few other conditions are in high intestinal obstruction. 其它少数情况是高位肠梗阻。 来自辞典例句
• This complication has occasionally occurred following the use of intestinal antiseptics. 这种并发症偶而发生在使用肠道抗菌剂上。 来自辞典例句

4 forgoing   

v.没有也行，放弃( forgo的现在分词 )

参考例句：

• Everything, in short, is produced at the expense of forgoing something else. 总之，每一种东西的生产，都得以牺牲放弃某些其他东西为代价。 来自互联网
• These aren't the only ones forgoing the morning repast, of course. 当然，他们并不是放弃早餐的唯一几个。 来自互联网

5 saturated   

a.饱和的，充满的

参考例句：

• The continuous rain had saturated the soil. 连绵不断的雨把土地淋了个透。
• a saturated solution of sodium chloride 氯化钠饱和溶液

6 cholesterol   

n.（U）胆固醇

参考例句：

• There is cholesterol in the cell of body.人体细胞里有胆固醇。
• They are determining the serum-protein and cholesterol levels.他们正在测定血清蛋白和胆固醇的浓度。

7 gut   

n.[pl.]胆量；内脏；adj.本能的；vt.取出内脏

参考例句：

• It is not always necessary to gut the fish prior to freezing.冷冻鱼之前并不总是需要先把内脏掏空。
• My immediate gut feeling was to refuse.我本能的直接反应是拒绝。

8 carbohydrates   

n.碳水化合物，糖类( carbohydrate的名词复数 )；淀粉质或糖类食物

参考例句：

• The plant uses the carbohydrates to make cellulose. 植物用碳水化合物制造纤维素。 来自《简明英汉词典》
• All carbohydrates originate from plants. 所有的碳水化合物均来自植物。 来自辞典例句

9 enzymes   

n. 酶，酵素

参考例句：

• It was said that washing powders containing enzymes remove stains more efficiently. 据说加酶洗衣粉除污更有效。
• Among the enzymes which are particularly effective are pepsin, papain. 在酶当中特别有效的是胃朊酶、木瓜酶。

10 nutritional   

adj.营养的，滋养的

参考例句：

• A diet lacking in nutritional value will not keep a person healthy.缺乏营养价值的饮食不能维持人的健康。
• The labels on food products give a lot of information about their nutritional content.食品上的标签提供很多关于营养成分的信息。

11 fend   

v.照料（自己），（自己）谋生，挡开，避开

参考例句：

• I've had to fend for myself since I was 14.我从十四岁时起就不得不照料自己。
• He raised his arm up to fend branches from his eyes.他举手将树枝从他眼前挡开。

12 bugs   

adj.疯狂的，发疯的n.窃听器( bug的名词复数 )；病菌；虫子；[计算机]（制作软件程序所产生的意料不到的）错误

参考例句：

• All programs have bugs and need endless refinement. 所有的程序都有漏洞，都需要不断改进。 来自《简明英汉词典》
• The sacks of rice were swarming with bugs. 一袋袋的米里长满了虫子。 来自《简明英汉词典》

13 partnership   

n.合作关系，伙伴关系

参考例句：

• The company has gone into partnership with Swiss Bank Corporation.这家公司已经和瑞士银行公司建立合作关系。
• Martin has taken him into general partnership in his company.马丁已让他成为公司的普通合伙人。

14 alignment   

n.队列；结盟，联合

参考例句：

• The church should have no political alignment.教会不应与政治结盟。
• Britain formed a close alignment with Egypt in the last century.英国在上个世纪与埃及结成了紧密的联盟。

15 revolves   

v.（使）旋转( revolve的第三人称单数 )；细想

参考例句：

• The earth revolves both round the sun and on its own axis. 地球既公转又自转。 来自《现代汉英综合大词典》
• Thus a wheel revolves on its axle. 于是，轮子在轴上旋转。 来自《简明英汉词典》

16 molecule   

n.分子，克分子

参考例句：

• A molecule of water is made up of two atoms of hygrogen and one atom of oxygen.一个水分子是由P妈̬f婘̬ 妈̬成的。
• This gives us the structural formula of the molecule.这种方式给出了分子的结构式。

17 wreaks   

诉诸（武力），施行（暴力），发（脾气）( wreak的第三人称单数 )

参考例句：

• Worshipping the sun wreaks havoc on skin. So does smoking. 过度晒太阳会毁掉好皮肤，吸烟也是如此。
• His hard work wreaks havoc in his personal life. 他拼命工作破坏了他的私人生活。

18 havoc   

n.大破坏，浩劫，大混乱，大杂乱

参考例句：

• The earthquake wreaked havoc on the city.地震对这个城市造成了大破坏。
• This concentration of airborne firepower wrought havoc with the enemy forces.这次机载火力的集中攻击给敌军造成很大破坏。

19 antibiotics   

n.（用作复数）抗生素；（用作单数）抗生物质的研究；抗生素，抗菌素( antibiotic的名词复数 )

参考例句：

• the discovery of antibiotics in the 20th century 20世纪抗生素的发现
• The doctor gave me a prescription for antibiotics. 医生给我开了抗生素。

20 vegetarian   

n.素食者；adj.素食的

参考例句：

• She got used gradually to the vegetarian diet.她逐渐习惯吃素食。
• I didn't realize you were a vegetarian.我不知道你是个素食者。

21 susceptible   

adj.过敏的，敏感的；易动感情的，易受感动的

参考例句：

• Children are more susceptible than adults.孩子比成人易受感动。
• We are all susceptible to advertising.我们都易受广告的影响。

22 hazy   

adj.有薄雾的，朦胧的；不肯定的，模糊的

参考例句：

• We couldn't see far because it was so hazy.雾气蒙蒙妨碍了我们的视线。
• I have a hazy memory of those early years.对那些早先的岁月我有着朦胧的记忆。

23 interferes   

vi. 妨碍，冲突，干涉

参考例句：

• The noise interferes with my work. 这噪音妨碍我的工作。
• That interferes with my plan. 那干扰了我的计划。

24 metabolism   

n.新陈代谢

参考例句：

• After years of dieting,Carol's metabolism was completely out of whack.经过数年的节食，卡罗尔的新陈代谢完全紊乱了。
• All living matter undergoes a process of metabolism.生物都有新陈代谢。

25 artery   

n.干线，要道；动脉

参考例句：

• We couldn't feel the changes in the blood pressure within the artery.我们无法感觉到动脉血管内血压的变化。
• The aorta is the largest artery in the body.主动脉是人体中的最大动脉。

26 vegetarians   

n.吃素的人( vegetarian的名词复数 )；素食者；素食主义者；食草动物

参考例句：

• Vegetarians are no longer dismissed as cranks. 素食者不再被视为有怪癖的人。
• Vegetarians believe that eating meat is bad karma. 素食者认为吃肉食是造恶业。

27 absolve   

v.赦免，解除（责任等）

参考例句：

• I absolve you,on the ground of invincible ignorance.鉴于你不可救药的无知，我原谅你。
• They agree to absolve you from your obligation.他们同意免除你的责任。

28 reminder   

n.提醒物，纪念品；暗示，提示

参考例句：

• I have had another reminder from the library.我又收到图书馆的催还单。
• It always took a final reminder to get her to pay her share of the rent.总是得发给她一份最后催缴通知，她才付应该交的房租。

29 bacterial   

a.细菌的

参考例句：

• Bacterial reproduction is accelerated in weightless space. 在失重的空间，细菌繁殖加快了。
• Brain lesions can be caused by bacterial infections. 大脑损伤可能由细菌感染引起。

30 killer   

n.杀人者，杀人犯，杀手，屠杀者

参考例句：

• Heart attacks have become Britain's No.1 killer disease.心脏病已成为英国的头号致命疾病。
• The bulk of the evidence points to him as her killer.大量证据证明是他杀死她的。

31 radically   

ad.根本地，本质地

参考例句：

• I think we may have to rethink our policies fairly radically. 我认为我们可能要对我们的政策进行根本的反思。
• The health service must be radically reformed. 公共医疗卫生服务必须进行彻底改革。

32 motive   

n.动机，目的；adv.发动的，运动的

参考例句：

• The police could not find a motive for the murder.警察不能找到谋杀的动机。
• He had some motive in telling this fable.他讲这寓言故事是有用意的。

33 niche   

n.壁龛；合适的职务(环境、位置等)

参考例句：

• Madeleine placed it carefully in the rocky niche. 玛德琳小心翼翼地把它放在岩石壁龛里。
• The really talented among women would always make their own niche.妇女中真正有才能的人总是各得其所。

34 format   

n.设计，版式；[计算机]格式，DOS命令:格式化(磁盘)，用于空盘或使用过的磁盘建立新空盘来存储数据；v.使格式化，设计，安排

参考例句：

• Please format this floppy disc.请将这张软盘格式化。
• The format of the figure is very tasteful.该图表的格式很雅致。

35 ideologies   

n.思想（体系）( ideology的名词复数 )；思想意识；意识形态；观念形态

参考例句：

• There is no fundamental diversity between the two ideologies. 这两种思想意识之间并没有根本的分歧。 来自《简明英汉词典》
• Radical ideologies require to contrast to their own goodness the wickedness of some other system. 凡是过激的意识形态，都需要有另外一个丑恶的制度作对比，才能衬托出自己的善良。 来自辞典例句

36 repression   

n.镇压，抑制，抑压

参考例句：

• The repression of your true feelings is harmful to your health.压抑你的真实感情有害健康。
• This touched off a new storm against violent repression.这引起了反对暴力镇压的新风暴。