经济学人下载:肠道、大脑和孤独症(1)

Paradigm shift is an overused term. Properly, it refers to a radical change of perspective on a topic,
范式转换是一个被过度使用的术语。准确的是，它指的是对一个话题观点的彻底改变，

such as the move from the physics of Newton to the physics of Einstein, or the introduction of plate tectonics into geology.
比如从牛顿物理学转变到爱因斯坦物理学，或是将板块构造学引入到地质学。

Such things are rare. Something which history may come to regard as a true paradigm shift does,
这种转变很少见。但历史上可能认为属于真正的范式转换的事情

however, seem to be going on at the moment in medicine.
似乎此刻正发生在医学领域。

This is a recognition that the zillions of apparently non-pathogenic bacteria on and in human bodies,
这是一种认识，即人体和体内有着无数非致病菌，

hitherto largely ignored, are actually important for people's health.
迄今为止这一点被很大程度的忽略了，这些病菌对人类健康非常重要。

They may even help to explain the development of some mysterious conditions.
它们甚至可能有助于解释一些神秘疾病的形成。

One such condition is autism—these days often called autism-spectrum disorder (ASD).
其中之一就是孤独症—如今经常被称为自闭症谱系障碍（ASD）。

ASD is characterised by repetitive, stereotypical and often restricted behaviour such as head-nodding,
ASD的特征是重复的、刻板的以及经常性的限制行为，如点头，

and by the difficulties those with it have in reading the emotions of, and communicating with, other people.
患者有无法读懂别人情绪以及和他人沟通的困难。

These symptoms are noticeable in children from the age of two onwards. Currently, in America, about one child in 59 is diagnosed with ASD.
这些症状在两岁以上的儿童中很明显。目前，在美国约每59个孩子中就有一个被诊断为ASD。

What causes ASD has baffled psychiatrists and neurologists
自20世纪中期，汉斯·阿斯伯格和利奥·坎纳首次对这种综合症状进行描述以来，

since the syndrome was first described, in the mid-20th century, by Hans Asperger and Leo Kanner.
ASD的病因就一直困扰着精神病学家和神经学家。

But the evidence is pointing towards the bacteria of the gut.
但证据正指向肠道细菌。

That suggestion has been reinforced by two recently published studies—one on human beings and one on laboratory rodents.
最近发表的两项研究进一步证实了这一观点—一项是针对人类，另一项是针对啮齿类实验动物。

The human study, the latest results of which came out a few weeks ago in Scientific Reports,
人类研究，其最新结果几周前发表在《科学报告》上

is being conducted by Rosa Krajmalnik-Brown of Arizona State University and her associates.
由亚利桑那州立大学的Rosa Krajmalnik-Brown及其合作人共同进行。

It was prompted by earlier work in which Dr Krajmalnik-Brown and James Adams, a colleague at Arizona State,
该研究由Krajmalnik-Brown和一位亚利桑那州同事James Adams的早期作品促成，

sequenced the DNA of gut bacteria from 20 autistic children to discover which species were present.
研究将20个孤独症孩子的肠道细菌DNA进行排序以发现其呈现出的是哪些种类。

They found that the children in their sample were missing hundreds of the thousand-plus bacterial species
他们发现样本儿童的千种细菌种类中缺失了有数百种

that colonise a "neurotypical" person's intestine. One notable absence was Prevotella.
千种细菌种类在“典型发育的”人体内进行殖民。一个值得注意的缺失是普雷沃氏菌属。

This bug, which makes its living by fermenting otherwise-indigestible carbohydrate polymers in dietary fibre,
这种细菌通过在膳食纤维中发酵其他不能消化的碳水化合物聚合物为生，

is abundant in the alimentary canals of farmers and hunter-gatherers in places like Africa,
非洲等地的农民和狩猎采集者的消化道中有大量的普氏菌，

rare in western Europeans and Americans, and nearly nonexistent in children with ASD
在西欧人和美国人消化道很少，在ASD儿童患者体内几乎不存在。

Their discovery led Dr Krajmalnik Brown and Dr Adams to the idea that restoring the missing bacteria might alleviate autism's symptoms.
他们的发现引导Krajmalnik Brown博士和Adams博士产生了一种想法：修复缺失的细菌或许可以减轻自闭症的症状。

Two years ago they tested a process called microbiota transfer therapy (MTT) on 18 autistic children aged between seven and 16.
两年前，他们对18名7到16岁的孤独症儿童患者进行了一种名为微生物群转移治疗（MTT）的测试。

Of their participants 15 were regarded, according to the Childhood Autism Rating Scale, as having "severe" autism.
其中15名参与者，根据《儿童孤独症评定量表》，被评定为重度自闭症。