经济学人下载:肠道细菌可以影响人的情绪

Bacteria and behaviour
细菌和行为学

Gut instinct
肠道反应

Tantalising evidence that intestinal bacteria can influence mood
逗引的证据表明，肠道细菌可以影响人的情绪

Sep 3rd 2011 | from the print edition

A GOOD way to make yourself unpopular at dinner parties is to point out that a typical person is, from a microbiologist’s perspective, a walking, talking Petri dish. An extraordinary profusion of microscopic critters inhabit every crack and crevice of the typical human, so many that they probably outnumber the cells of the body upon and within which they dwell.

一个让你自己在晚宴上不受欢迎的好方式就是，从微生物学家的角度指出，一位有代表性的人就是一个会走动并会说话的皮氏培养皿。每位有代表性的人的裂纹和缝隙里生活着无数的微小生物，它们的数目如此之多可能超过它们所依靠并栖息的人体细胞。

Happily, these microbes are mostly harmless. Some of them, particularly those that live in the gut, are positively beneficial, helping with digestion and keeping the intestines in good working order. That is no surprise—bacteria as much as people have an interest in keeping their homes in sound condition. What is surprising is the small but growing body of evidence which suggests that bacteria dwelling in the gut can affect the brain, too, and thereby influence an individual’s mood and behaviour. The most recent paper on the topic, published this week in the Proceedings of the National Academy of Sciences, reports (like much of the research in this field) on results in mice.

幸运地是，这些微生物大部分都是无害的。其中一些，特别是那些生活在消化道里的微生物，实际上是有益的，不仅有助于消化还保持肠道良好的工作秩序。这毫不奇怪——细菌和人一样也喜欢保持家园状态完好。奇怪的是，虽然数量不多，但越来越多的证据表明，生活在肠道的细菌也可能影响大脑，继而影响个人的情绪和行为。本周有关该主题的论文刊登在《美国国家科学院院刊》的一篇文章报道（像这个领域的许多研究一样）了应用小鼠的实验结果。

The researchers, led by Javier Bravo of University College, Cork, split their rodent subjects into two groups. One lot were fed a special broth containing Lactobacillus rhamnosus, a gut-dwelling bacterium often found in yogurt and other dairy products. The others were fed an ordinary diet, not fortified with microbes.

科克大学学院的哈维尔．布拉沃（Javier Bravo）带领下的研究人员将这些啮齿目动物分成两组。一组以一种在酸奶和其它乳制品中经常发现的含乳酸杆菌属鼠李糖乳杆菌（学名为Lactobacillus rhamnosus）的特别液体培养基喂食。另一组则以不用微生物强化的一般食物喂食。

The team then subjected the mice to a battery of tests that are used routinely to measure the emotional states of rodents. Most (though not all) of these tests showed significant differences between the two groups of animals.

然后，研究组人员对小鼠进行了一套测试。这套测试经常用于衡量啮齿类动物的情感状态。大部分（虽然不是所有的）测试表明，两组动物之间有着显著的不同。