These viruses are not your enemies, but critical to your health, protecting you from disease, maybe even killing cancer.

這些病毒並不是你的敵人，而是你健康的關鍵，它們保護你遠離疾病，甚至殺死癌症。

A new frontier of science, something truly new that we're only just beginning to understand.

科學的新領域，我們才剛剛開始瞭解的真正的新事物。

Let's dive into the wild world of the human virome.

讓我們一起進入人類病毒體的狂野世界。

You are an ecosystem.

你是一個生態系統。

You're a living, breathing ecosystem, made of up to 40 trillion cells.

你是一個活生生的生態系統，由多達 40 萬億個細胞組成。

This metropolis of flesh is home to the human microbiome, another 40 trillion bacteria that have a contract with your body.

這個肉體的大都市是人類微生物群的家園，另有 40 萬億個細菌與你的身體有契約關係。

They get to live here, and in return, they break down your meals.

它們在這裡生活，作為回報，它們會分解你的食物。

They synthesize vitamins in your gut, neutralize acid in your mouth, help balance your immune system, and they take up space, preventing harmful bacteria from getting in.

它們能在腸道中合成維生素，中和口腔中的酸，幫助平衡免疫系統，還能佔據空間，防止有害細菌進入。

This is a fragile balance.

這是一種脆弱的平衡。

Bacteria really only look out for themselves, multiplying and testing their boundaries.

細菌其實只為自己著想，它們不斷繁殖，不斷試探自己的極限。

To keep their numbers in check, your body's ecosystem needs a group of deadly predators.

為了控制它們的數量，你體內的生態系統需要一群致命的捕食者。

Viruses.

病毒

At least 10 trillion.

至少 10 萬億。

They're literally everywhere in your body, tens of thousands of different species.

它們在你體內無處不在，有數以萬計的不同種類。

At least a few trillion live in your gut, where also most of your resident bacteria are.

至少有幾萬億個細菌生活在你的腸道中，你的大部分常駐細菌也生活在這裡。

At least 18 billion on your skin, 100 million in each drop of your saliva, dozens of millions in your urinary tract.

皮膚上至少有 180 億個，每滴唾液中有 1 億個，尿道中有數千萬個。

Even in a single drop of the cerebrospinal fluid surrounding your nerves and brain, researchers found up to 10,000 viruses.

即使在一滴圍繞神經和大腦的腦脊液中，研究人員也發現了多達 10,000 種病毒。

While this sounds like a horrible idea at first, at least in the gut, around 97% of them are bacteriophages, or phages, bizarre creatures that are specialized in hunting down and killing resident bacteria and are not able to infect your cells.

雖然這乍聽起來很可怕，但至少在腸道中，大約 97% 的細菌都是噬菌體或噬菌體，它們是專門捕殺常駐細菌的怪異生物，無法感染你的細胞。

Instead, they kill trillions of bacteria every single day.

相反，它們每天都能殺死數萬億個細菌。

Together, these viruses make up the human virome, a symbiotic virus ecosystem that's completely unique to you and that seems to be crucial for your health.

這些病毒共同組成了人類病毒體，這是一個共生的病毒生態系統，對人體來說完全是獨一無二的，而且似乎對人體健康至關重要。

Let's get to know them and see how they support you and what happens if things go wrong.

讓我們來了解一下他們，看看他們是如何支持你的，以及如果出了問題會發生什麼。

The silent mass murderers of your body.

無聲無息地屠殺你的身體。

Inside your gut, a stealthy lambda phage floats through the buzzing crowds of bacteria looking for a victim.

在你的腸道內，一種隱蔽的λ噬菌體在嗡嗡作響的細菌群中穿梭，尋找受害者。

It has six legs, a long, thin body, and a big head made of geometric shapes filled with genetic material.

它有六條腿、細長的身體和一個由充滿遺傳物質的幾何圖形組成的大腦袋。

Each species is specialized in hunting one specific species of bacteria and ignores all others.

每種細菌都專門捕食一種特定的細菌，而對其他細菌視而不見。

Lambda is looking for Escherichia coli.

Lambda 正在尋找大腸桿菌。

This versatile bacteria is numerous in your gut, usually a good boy synthesizing vitamins for you.

這種多用途細菌在腸道中數量眾多，通常是為你合成維生素的好幫手。

But it also has a dark side.

但它也有陰暗的一面。

Some of them would much rather live inside your flesh and feast on your resources.

他們中的一些人更願意住在你的肉體裡，享用你的資源。

If there are too many or if they manage to invade your tissue, they can cause serious diseases.

如果數量過多或侵入組織，它們會引發嚴重的疾病。

So one of the most important jobs of the virome is to control the numbers of different bacteria populations by killing them.

是以，病毒體最重要的工作之一就是通過殺死細菌來控制不同細菌種群的數量。

Lambda has found a victim.

蘭達找到了一個受害者。

Spider-like legs get hold of a bacteria and grip it hard.

蜘蛛般的腿抓住了細菌，並使勁攥住。

Like an angry syringe, it violently rams its sharp bottom into the victim's body and releases its DNA.

它就像一個憤怒的注射器，猛烈地將鋒利的底部刺入受害者的身體，釋放出自己的 DNA。

Once inside, the proteins disable the defenses of the bacterium.

一旦進入體內，蛋白質就會使細菌的防禦功能失效。

It is now a factory under new management.

現在，它是一家由新管理層管理的工廠。

It's forced to build new viruses until the victim is filled up and bursts open, releasing a horde of fresh lambda viruses.

它被迫製造新的病毒，直到受害者被填滿並爆裂開來，釋放出大量新鮮的 lambda 病毒。

But its goal is not genocide.

但它的目標不是種族滅絕。

Phages need a healthy population of bacteria to survive, so sometimes they choose a way more sinister tactic.

噬菌體需要健康的細菌群體才能生存，是以有時它們會選擇一種更陰險的策略。

Instead of killing their victim, the virus integrates its DNA into the genome of the bacteria and goes to sleep.

病毒不會殺死受害者，而是將自己的 DNA 整合到細菌的基因組中，然後進入睡眠狀態。

When the bacteria multiplies, the virus DNA is multiplied too, until one day the viral DNA reawakens and suddenly decides to kill its unsuspecting victim.

當細菌繁殖時，病毒 DNA 也在繁殖，直到有一天病毒 DNA 甦醒過來，突然決定殺死毫無防備的受害者。

And here things become exciting.

在這裡，事情變得令人興奮起來。

Your virome also needs you to thrive.

你的病毒體也需要你來茁壯成長。

It's in its best interest that you're healthy, so some viruses inject genes into bacteria that actively make them support your body.

你的健康最符合它的利益，是以一些病毒會向細菌注入基因，使它們積極支持你的身體。

Some force their bacteria hosts to support your gut's mucus layer, break down complex carbohydrates from your food more efficiently, creating substances that protect against inflammation.

有些細菌會迫使它們的宿主支持腸道粘液層，更有效地分解食物中的複雜碳水化合物，產生抵禦發炎的物質。

And they alter what signals bacteria send to your immune cells.

它們還會改變細菌向免疫細胞發出的信號。

Basically, they're letting them know, we have things under control, you can chill out.

基本上，他們是讓他們知道，我們已經控制住了局面，你們可以冷靜下來了。

This may prevent allergic reactions or even protect you against autoimmune diseases.

這可以防止過敏反應，甚至保護您免受自身免疫性疾病的侵襲。

But of course, there's also a dark side to this story.

當然，這個故事也有陰暗的一面。

Some viruses don't care about our health.

有些病毒並不關心我們的健康。

Instead of helping, they turn harmless bacteria into deadly monsters.

它們非但沒有起到幫助作用，反而把無害的細菌變成了致命的怪物。

When viruses turn bacteria into killers.

當病毒把細菌變成殺手

Some species of bacteriophage carry dangerous genes for toxic substances.

某些種類的噬菌體攜帶有毒物質的危險基因。

When they take over their hosts, they can integrate into the genetic code of the bacteria where they lay as a deadly gift.

當它們佔據宿主後，就會融入細菌的遺傳密碼中，成為致命的禮物。

Like the case of the Vibrio cholerae and the CTX5 bacteriophage hunting them.

比如霍亂弧菌和獵殺它們的 CTX5 噬菌體。

Most strains of the cholerae bacteria are harmless and billions of them may live in your gut right now.

霍亂菌的大多數菌株都是無害的，你的腸道中現在可能生活著數十億株霍亂菌。

When CTX5 infect the bacteria, they gift them the genes for the cholera toxin, which permanently becomes part of their genetic lineage forever.

CTX5 感染細菌後，會將霍亂毒素的基因遺傳給它們，使其永遠成為細菌基因的一部分。

It's like handing a house cat a shotgun.

這就像給一隻家貓遞上一把獵槍。

Vibrio cholerae shower these toxins at the cells lining your gut, making them sick.

霍亂弧菌會向腸道內壁細胞噴射這些毒素，使它們生病。

They vomit large amounts of salt, which pulls out a flood of water into your intestines.

它們會嘔吐出大量的鹽，從而將大量的水排入腸道。

This causes explosive diarrhea and vomiting, draining your body of fluid.

這會導致爆炸性腹瀉和嘔吐，排幹體內的液體。

If untreated, about half of patients die.

如果不及時治療，約有一半的患者會死亡。

But for the phage and bacteria, this is great.

但對於噬菌體和細菌來說，這是件好事。

They're carried out of the body to infect more humans, spreading and multiplying further.

它們被帶出體外，感染更多的人類，進一步傳播和繁殖。

This strain of Vibrio cholerae is now a dangerous enemy of humanity thanks to this virus.

由於這種病毒的存在，霍亂弧菌的這一菌株現已成為人類的危險敵人。

Or the bacteria Staphylococcus aureus, which is hunted by the phage with the amazing name Phi SA3MS.

還有金黃色葡萄球菌，它被一種名為 Phi SA3MS 的噬菌體獵殺。

Usually the bacteria is mostly harmless and lives on your skin and inside your nose.

通常情況下，這種細菌大多是無害的，它生活在皮膚上和鼻子裡。

It doesn't do anything useful per se.

它本身沒有任何用處。

Its main job is to take up space, making it harder for hostile bacteria to colonize your body.

它的主要作用是佔據空間，使敵對細菌更難在體內繁殖。

But Phi SA3MS can change this quickly.

但 Phi SA3MS 可以迅速改變這種狀況。

It carries multiple dangerous genes, like giving a cat flamethrowers and grenades.

它攜帶多種危險基因，就像給貓配上了噴火器和手榴彈。

If such a modified Staphylococcus aureus bacteria gets into your body through a tiny cut, it becomes extremely dangerous.

如果這種經過改造的金黃色葡萄球菌通過一個小傷口進入人體，就會變得極其危險。

One of its new weapons are super antigens, which basically is like injecting your immune cells with cocaine.

它的新武器之一是超級抗原，這基本上就像是給你的免疫細胞注射可卡因。

The toxin completely breaks your carefully fine-tuned immune system.

這種毒素會徹底破壞你精心調試的免疫系統。

It activates all of your T-cells all at once and makes them flip out.

它能一下子激活你所有的 T 細胞，讓它們失控。

They release a tsunami of cytokines, activating all of your defenses at once.

它們會釋放海嘯般的細胞因子，同時激活你的所有防禦系統。

The infection is flooded with cells that can't fight the bacteria and cause heavy inflammation.

感染處充斥著無法對抗細菌的細胞，導致嚴重的發炎。

Your broken and confused immune cells have a really hard time fighting Staphylococcus aureus, which now invades, penetrating deep into your tissue.

你破碎混亂的免疫細胞很難對抗金黃色葡萄球菌，而金黃色葡萄球菌現在已經入侵，深入你的組織。

Your body is trying to seal the wounds and isolate the invader, but another new weapon it gained has the ability to just dissolve the barriers and penetrate even deeper.

你的身體正試圖封住傷口，隔離入侵者，但它獲得的另一種新武器卻能直接溶解障礙，滲透到更深的地方。

Before the onset of antibiotics, an infection with Staphylococcus aureus was very deadly, and we have Phi SA3MS to thank for making it even deadlier.

在抗生素問世之前，金黃色葡萄球菌感染是非常致命的，而 Phi SA3MS 則讓它變得更加致命。

But the viruses of our virome may also directly save your life by killing cancer.

但是，我們病毒體中的病毒也可能通過殺死癌症直接拯救你的生命。

Cancer-Killing Viruses Oncolytic viruses specialize in hunting and killing cancer, like the Newcastle disease virus or the Rio virus, who mostly ignore your healthy cells and instead hunt down tumors.

殺癌病毒 腫瘤溶解病毒專門獵殺癌症，如新城疫病毒或里約病毒，它們大多會忽略健康細胞，轉而獵殺腫瘤。

Cancer cells are broken mutants that evolve various ways to hide and fight back against your immune system.

癌細胞是一種殘缺不全的突變體，它們會進化出各種方法來躲藏和反擊免疫系統。

But as they get better at this, they get worse at other things, like fighting back viruses, a weakness to be exploited.

但是，當它們在這方面做得越來越好時，它們在其他方面就會變得越來越差，比如抵禦病毒，這是一個可以被利用的弱點。

Oncolytic viruses target the specific adaptations of cancer cells, hitting them where they are not ready to be hit.

腫瘤溶解病毒以癌細胞的特殊適應性為目標，在癌細胞沒有準備好接受攻擊的時候對其進行攻擊。

And worse for these cells, since their internal machinery is compromised, they can't defend themselves.

更糟糕的是，由於這些細胞的內部機制受到破壞，它們無法保護自己。

They're taken over and turned into virus production factories.

它們被接管，變成了病毒生產工廠。

Eventually, the new viruses leave the cancer cell, often killing it and carry on infecting other cancer cells nearby.

最終，新病毒離開癌細胞，往往會殺死癌細胞，並繼續感染附近的其他癌細胞。

This death and destruction is not subtle, and one side effect is that it attracts immune cells that immediately begin attacking the tumor with full force.

這種死亡和破壞並不隱蔽，其副作用之一是會吸引免疫細胞立即開始全力攻擊腫瘤。

What's even more impressive, these viruses seem to disrupt the artificial environment that tumors create to keep your immune system at bay.

更令人印象深刻的是，這些病毒似乎能破壞腫瘤為抑制免疫系統而創造的人工環境。

Oncolytic viruses are like infiltrators in a city at siege, opening the gates while killing defenders left and right, helping your immune cells to win the fight.

溶瘤病毒就像攻城戰中的潛入者，在打開城門的同時，殺死左右的守衛者，幫助免疫細胞贏得戰鬥。

In 2024, we don't know yet to what degree oncolytic viruses are part of your virome or more of a happy accident, but they seem to go well together with chemotherapy or radiation.

在 2024 年，我們還不知道溶瘤病毒在多大程度上是病毒體的一部分，或者更像是一個意外，但它們似乎與化療或放療配合得很好。

Eventually, they may become an important new tool to enable us to eliminate cancer and save millions of lives.

最終，它們可能成為一種重要的新工具，使我們能夠消除癌症，拯救數百萬人的生命。

We don't know what we'll learn in the next few years, but we now know that there are trillions of potential allies within us, killing and manipulating for better or worse.

我們不知道未來幾年會學到什麼，但我們現在知道，我們體內有數萬億潛在的盟友，他們或好或壞地殺戮和操縱著我們。

What an exciting time to be alive!

這是一個多麼令人興奮的時代！

Well, that was an interesting ride.

這真是一趟有趣的旅程。

Are there any more exciting stories?

還有更精彩的故事嗎？

Enter our friends from Imprint.

我們的朋友 Imprint 來了。

Their app is a unique new way of learning concepts and ideas in a beautifully visual, bite-sized and interactive way.

他們的應用程序是一種獨特的學習概念和想法的新方法，它以精美的視覺效果、一口大小和互動的方式進行學習。

If you're like us, you're easily caught up in scrolling mindlessly, watching more videos, scrolling on social media, watching more videos.

如果你和我們一樣，很容易陷入無意識的滾動中，觀看更多視頻，在社交媒體上滾動，觀看更多視頻。

Imprint gives you an outlet that actually makes you feel good about your screen time.

Imprint 為您提供了一個發洩管道，讓您對自己的螢幕時間感覺良好。

Their library offers lessons on all kinds of topics like psychology, history, philosophy, finance, productivity and more, spanning from quick reads that take you two minutes to run through to 80-unit full lesson courses that you can complete in only five minutes a day as you embark on a multi-week learning journey.

他們的資料庫提供各種主題的課程，如心理學、歷史、哲學、金融、生產力等，從兩分鐘就能讀完的快速閱讀到每天只需五分鐘就能完成的 80 個單元的完整課程，讓你開始為期多周的學習之旅。

Based on the latest science of learning, Imprint uses a beautifully animated and highly interactive approach to learning to help you retain what you learn and enjoy the process.

基於最新的學習科學，Imprint 採用精美的動畫和高度互動的學習方法，幫助你保持所學知識並享受學習過程。

We can see why it's been named Google's App of the Year.

我們可以理解為什麼它被評為谷歌年度應用程序。

Honestly, it's the best way to build a life of learning by turning to it whenever you're waiting in line, on public transport or just feel like having a moment to yourself.

老實說，每當你在排隊等候、乘坐公共交通工具或只是想享受片刻的時候，都可以求助於它，這是建立學習生活的最佳方式。

If you want to support Kurzgesagt and invest in your mind with just a few minutes each day, go to the link imprintapp.com slash kurzgesagt to start your seven-day free trial and get 20% off an annual membership.

如果您想支持 Kurzgesagt，每天只需幾分鐘就能投資自己的心靈，請訪問 imprintapp.com slash kurzgesagt 鏈接，開始為期七天的免費試用，並享受年度會員資格八折優惠。

Imprint.

版本說明