你知道吗? 我们超过一半的身体不是人类!

More than half of your body is not human, say scientists.
科学家们称，人身体里超过一半的组成“不是人类”。

Human cells make up only 43% of the body's total cell count. The rest are microscopic colonists.
人体只有43%的细胞属于人类，而其他的部分则是由非人类的微生物细胞群组成。

Understanding this hidden half of ourselves -- our microbiome -- is rapidly transforming understanding of diseases from allergy to Parkinson's.
理解关于我们的隐藏的一半，即我们的微生物群，正在迅速转变人们对过敏和帕金森病的认识。

The field is even asking questions of what it means to be "human" and is leading to new innovative treatments as a result.
该领域甚至提出了“人类”意味着什么的问题，并导致了新的创新疗法。

"They are essential to your health," says Prof Ruth Ley, the director of the department of microbiome science at the Max Planck Institute, "your body isn't just you".
马克斯普朗克研究所微生物群系科学部主管鲁斯·莱教授称：“它们对你的健康至关重要，你的身体不仅仅是你的。”

No matter how well you wash, nearly every nook and cranny of your body is covered in microscopic creatures.
无论你把自己洗得多干净，在你的身体几乎每个角落和缝隙中，仍然都生长着微生物。

This includes bacteria, viruses, fungi and archaea (organisms originally misclassified as bacteria). The greatest concentration of this microscopic life is in the dark murky depths of our oxygen-deprived bowels.
这些微生物包括细菌、病毒、真菌和古细菌（最初被误分类为细菌的生物体）。这种微生命最集中的地方是我们黑暗浑浊的、缺氧的肠道的深处。

Prof Rob Knight, from University of California San Diego, told the BBC: "You're more microbe than you are human."
加州大学圣地亚哥分校的罗布·奈特教授向BBC透露：“与其说你是人类，不如说你更多是微生物。”

Originally it was thought our cells were outnumbered 10 to one.
原先的认识是，我们人体中人类细胞的数量和微生物的比例超过了10比1。

"That's been refined much closer to one-to-one, so the current estimate is you're about 43% human if you're counting up all the cells," he says.
他说道：“这一数字已经更新为接近一比一了，所以目前的估计是，如果你将所有的细胞计算在内，你大约有43%的部分是人类细胞。”

But genetically we're even more outgunned.
但从遗传角度看，人类甚至要被甩得更远。

The human genome -- the full set of genetic instructions for a human being -- is made up of 20,000 instructions called genes.
人类基因组--人类的全套基因指令--由20,000个称为基因的指令组成。

But add all the genes in our microbiome together and the figure comes out between two and 20 million microbial genes.
但如果把人体内所有微生物的基因数目加起来，这个数字将会达到200万到2000万之间。

Prof Sarkis Mazmanian, a microbiologist from Caltech, argues: "We don't have just one genome, the genes of our microbiome present essentially a second genome which augment the activity of our own.
加州理工学院的微生物学家萨尔基斯·马兹曼尼亚教授认为：“我们不只有一个基因组，我们微生物组的基因基本上是第二个基因组，它增加了我们自己的活动。”

"What makes us human is, in my opinion, the combination of our own DNA, plus the DNA of our gut microbes."
“在我看来，是什么让我们成为了人类，就是我们自己的DNA和我们肠道内微生物DNA的结合。”