(单词翻译:单击)
Regular brushing and flossing are vital to the health of your teeth and gums.
定期刷牙、使用牙线对牙齿和牙龈的健康至关重要。
We all know that—it's been drummed into our heads since we first picked up a toothbrush.
我们都知道，自从第一次拿起牙刷，这件事就一直在我们的脑海里萦绕。
But brushing your teeth might not just be good for your oral health It could help protect your brain, too.
但刷牙可能不仅对口腔健康有好处，还能保护大脑。
Because according to studies over the last few decades,
因为根据过去几十年的研究，
there seems to be a connection between brushing your teeth and, of all things, Alzheimer's disease.
刷牙和老年痴呆症之间似乎存在关联。
This connection centers around an oral infection called periodontitis.
这种联系围绕着一种叫做牙周炎的口腔感染。
It's a condition that destroys soft tissue in the gums and eats away at the bone that supports the teeth.
这种病症会破坏牙龈的软组织，并侵蚀支撑牙齿的骨骼。
Left to its own devices, it will give bacteria a breeding ground, wreck someone's pearly whites, and leave them with bleeding gums.
任其自行发展的话，会提供一个滋生细菌的土壤，破坏牙齿，造成牙龈出血。
So, it's not a great time.
这可不是件好事。
There are a whole lot of things that can increase someone's risk of developing this, including a lack of teeth-brushing and factors like smoking and metabolic diseases.
有很多事会增加患这种病的风险，包括不刷牙，吸烟和代谢疾病等因素。
But thankfully, preventing it is often super straightforward.
但谢天谢地，阻止患上这种疾病往往非常简单。
Just keep good oral hygiene habits, and see a dentist regularly.
保持良好的口腔卫生习惯，还要定期看牙医。
Of course, that's often easier said than done.
当然，说起来容易做起来难。
So periodontitis is pretty common, with the Centers for Disease Control and Prevention in the United States citing
因此牙周炎相当普遍，美国疾病控制和预防中心指出，
that about 50% of people thirty or over have it to some degree.
30岁以上人群中大约有50%的人在某种程度上患有牙周炎。
From just a dental hygiene perspective, that's not good news.
从牙齿卫生的角度来看，这可不是什么好消息。
But some researchers also believe there's another consequence of this condition that a bacterium associated with it, called P. gingivalis,
但一些研究人员也认为，这种病症还有另一个后果，与之相关的一种叫做牙龈卟啉菌的细菌，
seems to be capable of contributing to Alzheimer's symptoms.
似乎会引发老年痴呆症的症状。
If you know a bit about Alzheimer's, you might be thinking, "This could make some sense!"
如果你对老年痴呆症有点了解，可能会想，“这可能有点道理！”
Because a common explanation for the disease's symptoms is that they're at least partly caused by plaques in the brain made of the compound amyloid beta.
因为对这种疾病症状的一个常见解释是，它们至少部分是由大脑中类淀粉β复合物组成的斑块所致。
That plaque hypothesis is still out there—although it's repeatedly failed to stand up to scrutiny.
尽管斑块假说屡屡经不起推敲，但这种说法仍然存在。
But regardless, this idea doesn't call amyloid beta into question.
但不管怎样，这种想法并未对类淀粉β提出质疑。
Instead, the two hypotheses fit together quite nicely.
相反，这两种假设非常吻合。
The idea is that, as periodontitis breaks down cells in the gums, P. gingivalis is able to break into the rest of the body.
其理念是，当牙周炎破坏牙龈细胞时，牙龈卟啉菌能侵入身体的其他部位。
From there, it can travel to more distant organs and establish bacterial colonies in places it's not meant to be.
它就这样传播到更远的器官，并在不该去的地方建立细菌菌落。
Including, as animal studies have confirmed, the brain.
动物研究证实，这些地方也包括大脑。
There, P. gingivalis releases toxins called gingipains, and that's when things start to get really messy.
牙龈卟啉菌在大脑释放出称为牙龈蛋白酶的毒素，此时情况开始变得糟糕。
The thinking is that these toxins compromise the tissue structure around the bacterial colonies.
这种想法认为，毒素会破坏细菌菌落周围的组织结构。
That makes the brain's protective barrier leaky, damages cells, and impacts cells' ability to function correctly.
这会使大脑的保护屏障泄漏，损害细胞，并影响细胞正常工作的能力。
So, in response to that, compounds that are associated with the damage, like amyloid beta,
因此，作为回应，与损伤相关的化合物，如类淀粉β，
could form and act like a scab over these wounds.
会在伤口上形成结痂。
There's even evidence that suggests P. gingivalis could make it harder for the brain to get rid of this stuff.
甚至有证据表明，牙龈卟啉菌会使大脑更难清除这些物质。
One study from the Journal of Alzheimer's Disease showed that the presence of this bacteria in the brain
2017年《阿尔茨海默病期刊》的一项研究表明，大脑中存在这种细菌时，
could alter sleep cycles by messing with how certain brain cells respond to light and set our bodies' clocks.
可能会扰乱某些脑细胞对光的反应，调整生物钟，从而改变睡眠周期。
And considering how the brain cleans itself of toxins as we sleep,
考虑到睡觉时大脑如何清除自身的毒素，
that kind of damage could have a direct effect on how the body could clean out both P. gingivalis and molecules like amyloid beta.
这种损伤可能直接影响到身体如何清除牙龈卟啉菌和类淀粉β等分子。
That's a lot of consequences for one measly gum bacterium.
对于一种微不足道的牙龈细菌来说，这种后果很严重。
Now, it is worth taking a second to say that Alzheimer's is a complicated disease with multiple factors.
值得一提的是，老年痴呆症是一种涉及多种因素的复杂疾病。
So even if someone has dental trouble, that doesn't mean their fate is sealed.
即使某人牙齿出现问题，也不意味着他们就会患上老年痴呆症。
But since there does seem to be a connection here, it's something people have been looking into.
但既然确实相关，人们就一直在研究这个问题。
They've been studying this relationship and even trying to figure out if P. gingivalis could be used as a biomarker.
人们研究这种关系，甚至试图弄清是否可以将牙龈卟啉菌用作生物标志物。
In other words, if you could test for it as a sign that someone might be at risk of developing Alzheimer's.
换句话说，可以对其进行测试，表明某人可能患上老年痴呆症。
And of course, they've also been trying to figure out how to tackle this bacterium head-on.
当然，他们也一直在试图找出正面对付这种细菌的方法。
With some promising results, I might add.
我要补充一下，存在一些有希望的结果。
In a study, researchers infected mice with this bacterium, and, as expected, saw it colonize the mice's brains.
在2019年的一项研究中，研究人员用这种细菌使老鼠感染。正如预期的那样，他们看到细菌在老鼠的大脑中大批生长。
They also saw an Alzheimer's-like increase in amyloid beta plaques.
他们还发现类淀粉β斑块老年痴呆症样性增加。
But, by injecting a small molecule that blocked P. gingivalis's ability to get energy,
但是，通过注射一种阻止牙龈卟啉菌获取能量的小分子，
the team was able to reduce both the number of bacteria and the associated inflammation.
研究小组能减少细菌数量和相关炎症。
This stopped the production of amyloid beta, and as the paper put it, "rescued" neurons in the hippocampus, a brain area vital for memory.
这样可以停止产生类淀粉β，正如那篇论文所说，“拯救”了海马体的神经元，海马体是大脑中对记忆至关重要的区域。
Of course, this study was only in mice, but more information may be just around the corner, because that small molecule is now being tested in humans, too.
当然，这项研究只是在老鼠身上进行，但可能很快就会有更多的信息，因为研究人员也正在人体上进行这种小分子的测试。
Two Phase I clinical trials testing the safety of the drug were completed in 2018,
两个测试药物安全性的第一阶段临床试验于2018年完成，我们在2020年拍摄这段视频时，
and when we filmed this video in 2020, a Phase 2 trial to further examine safety and efficacy was underway.
一个进一步检查安全性和有效性的第二阶段试验正在进行中。
That's a good starting point.
这是一个好的开始。
But while we wait for results, maintaining good oral hygiene to avoid periodontitis seems to be a great way to reduce risk, too.
但在我们等待结果的同时，保持良好的口腔卫生，避免患上牙周炎，似乎也是降低风险的一个好方法。
Alzheimer's is a slippery character.
老年痴呆症很难治疗。
Historically-speaking, scientists have had a hard time finding causes and treatments for it,
科学家们一直很难找到病因和治疗方法，
and this P. gingivalis thing is just one hypothesis among many.
牙龈卟啉菌只是众多假说中的一种。
Even so, these findings seem to provide a promising new target for Alzheimer's prevention,
即便如此，这些发现似乎为预防老年痴呆症提供了充满希望的新目标，
and hopefully, we'll see some fully-fledged treatments as a result.
希望我们能看到一些成熟的治疗方法。
Because when it comes to a disease like this… well, having multiple treatment options isn't a bad thing.
因为涉及这样的疾病时，有多种治疗选择并不是坏事。
This episode of SciShow Psych was made possible because of our patrons on Patreon-people
本集《心理科学秀》之所以能够制作出来，是因为Patreon上的赞助人，
who allow us to keep diving into the latest research and making videos like this.
他们使我们不断深入探寻最新的研究，并制作这样的视频。
So if you're a patron, thank you so much!
如果你是赞助人，非常感谢你！
If you'd like to consider joining our Patreon community, you can go to patreon.com/scishow.
如果你想加入我们的Patreon社区，请登录patreon.com/scishow。
And in any case, thanks for watching this episode. We're glad to have you.
感谢收看本集节目，有你们在真好。
