and humanity gets closer to sending people back to the moon — or even sending astronauts to Mars —

而人類也越來越接近把人送回月球，甚至把太空人送上火星。

we need to know how our bodies will handle long-term space travel.

我們需要知道我們的身體將如何處理長期的空間旅行。

And, thanks to the largest study ever published on the topic,

而且，由於有史以來最大的關於該主題的研究。

we now have a picture that's coming into focus...and that picture is full of challenges.

我們現在有一個畫面，正在進入焦點......而這個畫面充滿了挑戰。

Back in 2019, NASA published the first ever space twin study.

早在2019年，美國宇航局就公佈了有史以來第一份太空雙胞胎研究報告。

This compared twins Mark and Scott Kelly before, during, and after Scott spent 340 days in space —

這比較了雙胞胎馬克和斯科特-凱利在斯科特在太空中度過340天之前、期間和之後--。

that's the longest any U.S. astronaut has consecutively spent in spaceflight — while Mark stayed here on Earth.

這是美國太空人在太空飛行中連續停留時間最長的一次，而馬克則留在地球上。

That study gave us so much insight into how the human body changes in microgravity:

那項研究讓我們對人體在微重力下的變化有了深刻的認識。

from telomere shortening to gut microbiome changes to rapid alteration of gene expression.

從端粒縮短到腸道微生物組變化再到基因表達的快速改變。

It also told us there was still so much to learn...and boy, did 2020 deliver.

它還告訴我們還有很多東西需要學習......孩子，2020年確實做到了。

A set of nineteen new studies builds on the results of the Kelly Twins study,

一組19項新的研究建立在Kelly Twins研究結果的基礎上。

reanalyzing some of that data and comparing those results to measurements between 56 astronauts in total.

重新分析其中的一些數據，並將這些結果與總共56名太空人之間的測量結果進行比較。

Plus ten more papers are in pre-print now, being reviewed and set for publication soon to add even more to this data set.

另外，現在還有十篇論文正在預印中，正在審核，很快就會發表，為這個數據集增加更多的內容。

This is the largest study of its kind, the most information EVER collected about what happens to the human body in space.

這是同類研究中最大規模的研究，是有史以來收集到的關於人體在太空中發生的最多資訊。

So, what did we find?

那麼，我們發現了什麼？

The researchers have identified, for the first time, a core set of mammalian adaptations in response to spaceflight.

研究人員首次發現了一組響應於太空飛行的哺乳動物核心適應性。

We see these changes across species: humans, mice and other animals.

我們在不同的物種中看到這些變化：人類、老鼠和其他動物。

The biggest one?

最大的一個？

Mitochondrial dysfunction.

線粒體功能障礙。

You may think of the mitochondria as that famous 'powerhouse of the cell'—

你可能會認為線粒體是那個著名的 "細胞的動力源"--。

it generates most of the energy a cell needs and so enables the proper function of all your tissues and organs.

它能產生細胞所需的大部分能量，是以能使你的所有組織和器官正常運作。

So, as you might imagine, keeping your mitochondria working is pretty important.

所以，正如你所想象的那樣，保持線粒體工作是相當重要的。

Using new techniques that allowed a really in-depth look at changes in the astronauts' genomes and protein expression,

利用新技術，可以真正深入瞭解太空人基因組和蛋白質表達的變化。

mitochondrial changes were consistent across the dataset.

線粒體的變化在整個數據集中是一致的。

And even though the scientists are still unsure what EXACTLY may be the underlying cause of this mitochondrial disturbance,

儘管科學家們仍不確定這種線粒體紊亂的根本原因可能是什麼。

they think it's likely oxidative stress caused by the extreme environment of space.

他們認為這很可能是太空極端環境造成的氧化應激。

This, essentially, is damage caused to cells by stress.

這，本質上是壓力對細胞造成的傷害。

Stress releases these harmful compounds called reactive oxygen species, causing genetic changes

壓力會釋放這些有害的化合物，稱為活性氧物種，導致基因改變

that, in turn, cause changes in metabolic pathways.

進而引起代謝途徑的變化。

And honestly, the 'changes' they describe in this dataset are hilariously complicated.

說實話，他們在這個數據集中描述的 "變化 "複雜得令人發笑。

But the upshot of the whole mitochondrial discovery is that it gives us a way to put together a lot of the pieces.

但整個線粒體發現的結果是，它給我們提供了一種方法，可以把很多碎片放在一起。

See, changes in mitochondrial function are likely the underlying cause of a lot of the other weird stuff we see in astronauts,

你看，線粒體功能的變化很可能是我們在太空人身上看到的很多其他奇怪東西的根本原因。

like disrupted circadian rhythm, immune system dysfunction, and changes in organ activity.

如晝夜節律紊亂、免疫系統功能失調、器官活動變化等。

Because that was the other main discovery.

因為那是另一個主要發現。

Turns out, space is really hard on your liver!

原來，空間對肝臟的傷害真的很大!

The liver undergoes more changes in gene and protein expression than any other organ while in space.

肝臟在太空中經歷的基因和蛋白質表達變化比任何其他器官都要多。

And this is because your liver, with its role in blood filtration,

而這是因為你的肝臟，有過濾血液的作用。

is really important in sensing changes in blood composition and keeping your body as habitable as possible —

是真正重要的感知血液成分的變化，並保持你的身體儘可能的居住--。

or, to put it more scientifically, maintaining homeostasis.

或者說得更科學一點，就是維持穩態。

So, apparently, it has to work extra hard while in space.

所以，很明顯，它在太空中要特別努力工作。

The dataset also confirmed that many astronauts' telomeres lengthen while in space,

該數據集還證實，許多太空人在太空中的端粒會延長。

but then shorten significantly when they come back to Earth — just like Scott Kelly's did in the Twins study.

但當它們回到地球時，又會明顯縮短--就像斯科特-凱利在雙胞胎研究中所做的那樣。

The hypothesis for this is also...oxidative stress, problematic because

這個假設也是......氧化應激，有問題的原因是。

telomeres are essential for preventing damage to your chromosomes.

端粒是防止染色體受損的關鍵。

Not all of the changes were necessarily bad.

並非所有的變化都一定是壞的。

Scott Kelly experienced a decrease in blood cell mutations during his year in space.

斯科特-凱利在太空中的一年中，血細胞突變減少。

Some astronauts exhibited increased levels of genetic tools that allowed them adapt slightly

一些太空人表現出更高水平的遺傳工具，使他們能夠稍微適應。

to the effects of radiation and microgravity.

輻射和微重力的影響。

And this 2020 dataset also confirmed that astronaut gut microbiomes take on a unique profile while in space

而這個2020年的數據集也證實了太空人在太空中的腸道微生物組具有獨特的特徵。

(which I just think is super cool).

我只是覺得超級酷）。

Overall, all of this gives us a much more robust picture of what goes on in the body while in space,

總的來說，所有這些都讓我們對身體在太空中發生的事情有了更有力的瞭解。

and what potential drugs or discoveries could make long-term spaceflight physiologically possible.

以及哪些潛在的藥物或發現可以使長期空間飛行在生理上成為可能。

And as the astronaut core is only getting more diverse, scientists want to conduct more studies

而太空人核心只會越來越多樣化，科學家們希望進行更多的研究。

with even more human participants on even longer spaceflights to make our understanding of bodies in space

有更多的人参加更長時間的太空飛行，使我們對太空中的身體有更多的瞭解。

as well-rounded as possible.

儘可能的全面。

Because work like this doesn't just keep astronauts safe before and after their trips off-Earth —

因為這樣的工作不僅能保證太空人在離開地球前後的安全，還能保證他們的安全。

it gives us even more insight into human health here on the planet too.

它讓我們對地球上的人類健康有了更深入的瞭解。

You can check out my previous video on the initial results of the NASA twin study here!

你可以在這裡查看我之前關於NASA雙胞胎研究初步結果的視頻!

Make sure you subscribe to Seeker for all of your spaceflight news,

請確保您訂閱了Seeker的所有航天新聞。

and if you have another topic you want us to cover in this area, let us know down in the comments below.

如果你有其他的主題，你想讓我們在這個領域覆蓋，讓我們知道在下面的評論。

As always, thanks so much for watching, and I'll see ya next time.

一如既往，感謝大家的觀看，我們下次再見。