如果医生告诉你 你感染蠕虫了
If your doctor told you that you were infected with worms,
你可能首先想问的是
your first question would probably be,
我能多快把虫驱了
“How quickly can I get rid those worms in me?”
这我能理解
And I get that.
我的意思是 瞧
I mean, look,
你不想让蠕虫在你的肠道里蠕动
you don’t want worms wriggling around inside your intestines.
因为这足以恶心到任何人
It’s enough to gross anybody out.
但是如果我告诉你
But what if I told you
你可能还想让寄生虫待在你的体内呢？
that you might want to have parasitic worms inside you?
因为有些医生实际上已经发现了
Because some doctors have actually found a connection
体内寄生虫和防止出现
between having worms and not having
过敏或者关节炎等免疫系统疾病具有相关性
immune system problems like allergies or arthritis.
该观点称 这些寄生虫已经在我们体内
The idea is that these worms have set up shop
安营扎寨许久
in our bodies for so long.
从进化角度来说
Evolutionarily speaking,
我们的免疫系统可能已经
that our immune systems might have
适应了它们的存在
gotten used to them.
中肯地说 体内没有了寄生虫
To the point that being worm-free
反而会产生别的问题
can actually cause its own issues.
这是卫生假说的其中一部分
It’s part of the hygiene hypothesis,
卫生假说是流行病学家在
which was proposed by epidemiologists
20世纪80年代提出的 解释了为何
back in the 1980s to explain why
过敏和哮喘这样的自身免疫性疾病
allergies and autoimmune conditions like asthma are
在今天比过去还要普遍得多
so much more common today than they used to be.
根据这个假说
According to the hypothesis,
人的免疫系统可能会因为
people’s immune systems might be out of whack
体内过于干净而发生紊乱
because we’re too clean.
过滤水并不是从一开始就有的
Filtered water didn’t exist for an awful long time,
更不用说洗手液机了
let alone hand sanitizer stations.
所以在进化史中的大部分时期
So for much of our evolutionary history,
每个人都会经常接触到
everyone was constantly exposed to things
细菌和寄生虫之类的东西
like bacteria and parasites.
免疫系统的工作就是防止这些东西
It’s your immune system’s job to keep these things
进入体内 寄居并且伤害人们的身体
from settling in and harming you when they get inside.
所以当免疫系统发现外来物时
So when it finds something foreign,
就会引发炎症来保卫你的身体
it defends your body by triggering inflammation
这表现为发热 发红 肿痛
that hot, red, swollen achiness.
这些症状产生的原因是这块区域
Those symptoms happen because the area is flooded
充斥着一大群白细胞
with an army of white blood cells.
他们释放的化合物要么攻击外来物质
The compounds they release either attack the foreign material,
要么召唤援军
or call in reinforcements.
但这些负责攻击的化合物
But the compounds that do the bulk
不仅仅只攻击外来入侵者
of the attack don’t just target invaders.
它们也会伤害你自身的细胞
They can harm your own cells, too,
你的身体也会陷入到交叉火力中
and your body can get caught in the crossfire,
这会给你带来伤害和疼痛
which causes damage and pain.
过敏就是炎症的一个特例
Allergies, for example, are a special case of inflammation,
这是身体对通常无害的物质
where the body is overreacting
如花粉和粉尘 所做出的过度反应
to something that’s usually harmless, like pollen or dust.
自身免疫性疾病就来自于
And autoimmune disorders come from parts
发生炎症的身体部位
of your own body triggering inflammation.
比如类风湿性关节炎
Like rheumatoid arthritis,
该病通常会导致人体关节
where joints basically become
永久性发炎或者多发性硬化
permanently inflamed, or multiple sclerosis,
免疫系统攻击神经周围的保护层
where the immune system attacks the protective coating around nerves,
有时候也攻击神经本身
and sometimes the nerves themselves.
这些状况在现今变得越来越普遍
All these conditions are becoming more common these days,
尤其是在发达的国家
especially in wealthy nations
他们有高质量医疗保健体系
where you would think easy access
因此你会认为他们能避免这些情况
to high-quality medical care would prevent them.
而这就是产生寄生虫 即蠕虫 的地方
That’s where parasitic worms, collectively known as helminths, come in.
蠕虫类里包含了
The group includes things
如绦虫 线虫 吸虫
like tapeworms, nematodes, and flukes,
它们靠吸取营养生存
which steal nutrients to survive.
大部分舒服地呆在其它动物的肠子和血液里
Most get cozy in another animal’s intestines or blood.
有些种类的寄生虫会带来极为严重的症状
Some species cause pretty severe symptoms
如导致血吸虫病的寄生虫
like the worms behind schistosomiasis,
他们会导致贫血 肝脏衰竭 膀胱癌
which can cause anemia, liver failure, bladder cancer,
或者其它可怕的状况
or other awful conditions.
但是很多寄生虫不会这样
But many others don’t.
打个比方 就算你现在体内有绦虫
Like, if you had a tapeworm right now,
你可能也不知道
you might have no idea,
这实际上是个很可怕的想法
which is a super creepy thought, actually.
至于那些更为良性的种类
For those more benign species,
如果你的免疫系统向它们发射核武器
the fallout that can come from launching your immune system nukes at them
那后果可能比蠕虫本身带来的伤害更为严重
can be worse than the damage from the worms themselves,
这就是为什么许多流行病学家认为
which is why some epidemiologists think
我们的免疫系统在某种程度上已经进化到
that our immune systems have evolved to function
可以在体内有特定的寄生虫的情况下运作
with certain parasites, to some extent.
这可能听起来很难理解
That might sound kind of backwards,
但是研究已表明在寄生虫感染较少的地方
but studies have found that rates of asthma and allergies
患哮喘和过敏的概率更高
are higher in places with fewer parasite infections,
比如那些卫生设施和医疗保健体系更完善的地方
like those with more sanitation and access to healthcare.
即便如此 如果蠕虫已经引发了健康问题
And even though treatment is obviously worth it
那治疗显然是值得的
when the worms are causing health problems.
其他研究表明
Other research has suggested
消灭寄生虫可能会产生意想不到的副作用
that getting rid of parasites can have unintended side effects.
例如 在2006年的一项研究中
For instance, in a 2006 study,
加蓬的317名儿童在经历体内驱虫后
ridding 317 children from Gabon of their intestinal parasites
其中的一些人对螨虫产生了过敏反应
made some of them have an allergic reaction to mites.
同样地 2011年有一项针对2500多名乌干达妇女的研究
Similarly, a 2011 study looked at more than 2500 Ugandan women,
她们中的一些人
some of whom were treated
在怀孕期间接受了驱虫药物的治疗
with deworming meds while they were pregnant.
虽然这种疗法有助于预防
While the treatment helped prevent
成人和婴儿可能出现的严重并发症
potentially serious complications in both adults and babies,
但它增加了
it increased the likelihood
孩子患湿疹或哮喘的可能性
that the kids would have eczema or wheezing,
这都是过敏反应的症状
both symptoms of allergic responses.
一项针对12名多发性硬化症患者的小型研究发现
And a small study of 12 multiple sclerosis patients
随着时间的推移 体内有蠕虫的患者
found that those with worms
受到的神经损伤更少
had less nerve damage over time.
但当其中四人接受治疗时 他们的病情恶化了
But when 4 of them were treated, their multiple sclerosis symptoms got worse.
这似乎很奇怪 寄生虫感染
It seems strange that having a parasite infection
可以让你在这些特定的方面保持健康
could keep you healthier in these specific ways.
因此为了找出这种模式存在的原因
So to figure out why this pattern exists,
免疫学家观察了我们的身体
immunologists have looked at how our bodies
对寄生虫感染的反应
respond to helminth infections.
他们发现
They’ve found that some parasitic worms seem
一些寄生虫似乎可以
to make our immune systems kind of hold back
通过释放抗炎信号来抑制我们的免疫系统
by releasing anti-inflammatory signals that make it
这样我们的身体就不会反应过度
so our bodies don’t go overboard
进而试图杀死寄生虫
trying to kill the parasites.
与此同时
At the same time,
它们还能减少导致自身免疫性疾病的炎症
they’re also reducing the inflammation that leads to
以及对过敏原的过度反应
autoimmune conditions, and the overreaction to allergens.
寄生虫还能刺激调节T细胞的产生
Helminths could also spur the production of regulatory T cells,
这些细胞能识别你身体中
which recognize parts of your body
可能引发炎症的部分并降低其反应
that might trigger inflammation and turn down the response.
这些细胞通常会阻止你的免疫系统
These cells normally keep your immune system
在入侵者已经死亡后
from staying in attack mode
还处于攻击模式
after the invaders are already dead
或者防止你对花粉等无害物质做出反应
or from freaking out in response to harmless stuff like pollen.
这可以从那12名多发性硬化症患者身上得到了证实
And this was seen in those 12 multiple sclerosis patients
那些有寄生虫的患者有更多的调节T细胞
those with parasites had more regulatory T cells
来识别一种能触发神经组织攻击的蛋白质
recognizing a protein that triggers the attack of neural tissue,
这就是为什么他们的神经损伤更少
which could be why they had less nerve damage.
医生们正试图弄清楚
Doctors are trying to figure out what it is
蠕虫是如何触发的这些调节机制
about the worms that triggers these regulatory mechanisms.
这样的话他们就能够
That way, they might be able to
用这种化合物来治疗
turn the compounds involved into treatments
自身免疫性疾病
for all kinds of autoimmune diseases.
这是相对完全没有蠕虫来说 蠕虫所带来的好处
It would be all the benefits of worms, without all the worms!
不过要搞清楚 我们科学秀并不推荐
To be clear, we here at SciShow do not recommend
你为了治疗坚果过敏
infecting yourself with worms to try like,
而主动感染上寄生虫
cure your tree nut allergy.
除非这是你的医生给你开的处方
Unless your doctor prescribes them,
当然这也是有可能的
which is kind of possible.
一些医生正在对卫生学说进行
Some doctors are putting the hygiene hypothesis
终级医学测试——临床试验
to the ultimate medical test: clinical trials.
大部分的试验还处在初级阶段
Most of these trials are still in the early stages,
结果是喜忧参半的
and results are mixed.
但是这些研究人员还是保持乐观
But some researchers remain hopeful.
我们已经知道我们的健康取决于
We already know that our health depends on
我们体内及体表各种有机体
tons of other organisms that live on and in our bodies.
那么大概也包括寄生虫
So maybe parasitic worms are just part of that.
只不过大了点
Just a lot bigger.
但再说一遍 我们并没有建议
But again, we are not recommending
你们现在开始不洗手
that you stop washing your hands
或者光脚踩在人类粪便里
or, like, walk around barefoot around a lot of human feces.
别那样做
Don’t do that.
如果你想要了解更多
If you want to learn more
关于你的健康 药物以及保健策略的知识
about your health and medicine and healthcare policy,
你可以前往我们的姐妹频道
you can dive even deeper
由亚伦卡罗尔医生主持的《医疗诊断》
by checking out our sister channel Healthcare Triage hosted
来进行更深入的探索
by Dr. Aaron Carroll over at youtube.com/healthcaretriage.