Have you ever wondered what is inside your dental plaque? Probably not, but people like me do. I'm an archeological geneticist at the Center for Evolutionary Medicine at the University of Zurich, and I study the origins and evolution of human health and disease by conducting genetic research on the skeletal and mummified remains of ancient humans. And through this work, I hope to better understand the evolutionary vulnerabilities of our bodies, so that we can improve and better manage our health in the future.
你是否曾经好奇过 你的牙垢里有些什么成分? 估计没有吧,但像我这样的人 却会思考这个问题。 我是个考古遗传学家, 在苏黎世大学的 进化医药中心工作。 我通过研究远古人类的 骨骼和干尸的基因, 来研究人类健康和疾病的 根源以及演化。 通过这项工作,我希望能更好地理解 人类身体的进化脆弱性, 以便我们在将来能够改善 和更好地管理我们的身体健康。
There are different ways to approach evolutionary medicine, and one way is to extract human DNA from ancient bones. And from these extracts, we can reconstruct the human genome at different points in time and look for changes that might be related to adaptations, risk factors and inherited diseases. But this is only one half of the story.
研究进化医药有不同的方法。 其中一种是从远古人类的骨头上 提取DNA, 从这些提取物当中, 我们可以重建在 不同时间点的人类基因组, 并寻找可能与适应环境、风险因素和 遗传疾病相关的变化。 但这只是故事的一半。
The most important health challenges today are not caused by simple mutations in our genome, but rather result from a complex and dynamic interplay between genetic variation, diet, microbes and parasites and our immune response. All of these diseases have a strong evolutionary component that directly relates to the fact that we live today in a very different environment than the ones in which our bodies evolved. And in order to understand these diseases, we need to move past studies of the human genome alone and towards a more holistic approach to human health in the past.
当今最重大的健康挑战 并不是由人类基因组中的 一些简单突变造成的, 而是源于遗传变异、饮食、 微生物、寄生虫 和我们的免疫反应之间的 一种复杂,动态的 相互作用。 所有这些疾病都有 一个很强的进化成分 与一个事实直接相关, 即我们如今生活在一个 与我们的身体发生进化时 截然不同的环境中。 为了理解这些疾病, 我们需要带着过去 对人类基因组的研究一起, 向一个更加整体的方向前进, 来研究过去的人类健康状况。
But there are a lot of challenges for this. And first of all, what do we even study? Skeletons are ubiquitous; they're found all over the place. But of course, all of the soft tissue has decomposed, and the skeleton itself has limited health information. Mummies are a great source of information, except that they're really geographically limited and limited in time as well. Coprolites are fossilized human feces, and they're actually extremely interesting. You can learn a lot about ancient diet and intestinal disease, but they are very rare.
但是我们面临诸多挑战。 首先,我们的研究对象是什么? 骨骼随处可见,到处都可以找到, 但是所有的软体组织都腐坏了, 而骨骼本身所携带的 健康信息是很有限的。 干尸是一个很好的信息来源, 可是干尸出现的地域范围很狭小, 时间范围也很短。 粪化石是人类排泄物的化石, 实际上,它们很有意思, 你可以从中了解很多 古代饮食和肠道疾病的信息, 但它们很稀少。
(Laughter)
(笑声)
So to address this problem, I put together a team of international researchers in Switzerland, Denmark and the U.K. to study a very poorly studied, little known material that's found on people everywhere. It's a type of fossilized dental plaque that is called officially dental calculus. Many of you may know it by the term tartar. It's what the dentist cleans off your teeth every time that you go in for a visit. And in a typical dentistry visit, you may have about 15 to 30 milligrams removed. But in ancient times before tooth brushing, up to 600 milligrams might have built up on the teeth over a lifetime.
所以为了解决这个问题, 我组织了一队国际研究学者, 他们来自瑞士,丹麦和英国, 来研究一种从各地的人 身上都可以找到的, 我们却所知甚少的材料。 它是一种牙垢化石。 官方说法是dental calculus(牙垢)。 牙垢也叫牙石, 就是每次你去看牙的时候 牙医从你的牙齿中清除的东西。 每次看牙 你可能会被清除15到30毫克的牙垢。 但是在古代,在有刷牙行为之前, 人的一生中在牙齿上可能会积累 将近600毫克的牙垢。
And what's really important about dental calculus is that it fossilizes just like the rest of the skeleton, it's abundant in quantity before the present day and it's ubiquitous worldwide. We find it in every population around the world at all time periods going back tens of thousands of years. And we even find it in neanderthals and animals.
牙垢之所以重要的原因是 它就像其他骨骼一样可以变成化石。 它数量丰富,从古至今都随处可见, 几乎在全球 每个人口中都能找到牙垢。 其时间段可追溯到数万年以前。 我们甚至在尼安德特人和 动物身上也找到了牙垢。
And so previous studies had only focused on microscopy. They'd looked at dental calculus under a microscope, and what they had found was things like pollen and plant starches, and they'd found muscle cells from animal meats and bacteria. And so what my team of researchers, what we wanted to do, is say, can we apply genetic and proteomic technology to go after DNA and proteins, and from this can we get better taxonomic resolution to really understand what's going on?
之前的研究 仅仅关注了显微学。 人们在显微镜下观察牙垢, 发现了花粉和 植物淀粉, 他们在动物的肉和细菌中 发现了肌细胞。 所以,我的研究小组的计划是, 是否能应用 遗传和蛋白质组学技术, 来跟踪DNA和蛋白质。 从这一点出发,我们是否能够 得到更好的生物分类学解决方案 来真正理解目前的状况。
And what we found is that we can find many commensal and pathogenic bacteria that inhabited the nasal passages and mouth. We also have found immune proteins related to infection and inflammation and proteins and DNA related to diet. But what was surprising to us, and also quite exciting, is we also found bacteria that normally inhabit upper respiratory systems. So it gives us virtual access to the lungs, which is where many important diseases reside.
我们发现了 位于鼻腔通道和嘴巴里的 很多共生体和病原细菌。 我们也找到了关于 感染和炎症的免疫蛋白, 以及与饮食有关的蛋白质和DNA。 但是令我们感到奇怪又兴奋的是, 我们也发现了 通常位于上呼吸道系统的细菌, 所以它给了我们接触肺部的虚拟途径, 而肺正是感染很多重要疾病的部位。
And we also found bacteria that normally inhabit the gut. And so we can also now virtually gain access to this even more distant organ system that, from the skeleton alone, has long decomposed. And so by applying ancient DNA sequencing and protein mass spectrometry technologies to ancient dental calculus, we can generate immense quantities of data that then we can use to begin to reconstruct a detailed picture of the dynamic interplay between diet, infection and immunity thousands of years ago.
我们也找到了 通常位于肠道的细菌。 所以我们现在也可以接触到 这个隔得更远的器官系统, 而相对骨骼本身来说, 这个系统早就腐化了。 因此,通过对古代牙垢 应用DNA测序 和蛋白质谱技术, 我们可以获得大量的数据, 并利用这些数据来开始重建 千万年前的饮食, 感染和免疫之间 富有活力的相互作用。
So what started out as an idea, is now being implemented to churn out millions of sequences that we can use to investigate the long-term evolutionary history of human health and disease, right down to the genetic code of individual pathogens. And from this information we can learn about how pathogens evolve and also why they continue to make us sick. And I hope I have convinced you of the value of dental calculus.
那么起初的想法 现在已经被付诸实施, 我们得到了数百万的序列 来调查人类 健康和疾病的长期进化史, 一直到个体病原体的遗传密码。 从这个信息中, 我们可以学到病原体是如何进化的, 以及为什么它们能够一直让人生病。 我希望我已经让你们 相信了牙垢的价值。
And as a final parting thought, on behalf of future archeologists, I would like to ask you to please think twice before you go home and brush your teeth.
最后,我想要 代表未来的考古学家, 请求你们在回家刷牙之前 三思而后行。
(Applause)
(鼓掌)
Thank you.
(谢谢)
(Applause)
(鼓掌)