如何改善肠道微生物组以促进大脑与整体健康

我觉得，你知道，是那个虾让我不舒服的。

The, you know, I think it was the shrimp that made me sick.

我就是不想再吃那个了。

I just don't want any more of that.

或者我再也不去那家餐厅了，因为我在那儿吃完饭后大约一个小时，就开始觉得特别不舒服。

Or I'm never going back to that restaurant again because after I ate there about an hour later, I started feeling really not well.

我有点发烧的感觉，但肚子也不舒服。

I felt kind of feverish, but my gut didn't feel well.

我的消化真的很不正常。

My digestion was really off.

所有这些信息都在前额叶皮层进行有意识的处理，但立即决定停止进食或继续吃某样东西，靠近或远离某物，这些是由位于我们所说的潜意识层面的神经回路做出的，但实际上我们指的是新皮层以下的层面。

All of that kind of information is handled in the prefrontal cortex at a conscious level, but the immediate decision to stop eating or to eat more of something, to move towards something or away from it, that's made by neural circuits that reside at the, we would say the subconscious level, but what we really mean is below the level of the neocortex.

皮层以下基本上意味着在我们的意识水平之下。

Below the cortex means essentially below our level of conscious awareness.

所以我们讨论了肠道内传递给大脑的两类信息：化学信息，即关于肠道内存在的营养物质的信息；以及机械信息，即肠道的扩张或未扩张等等。

So we talked about two types of information within the gut that are communicated to the brain, chemical information, meaning information about the nutrients that happen to be there and mechanical information, distension of the gut or lack of distension and so forth.

我们之前提到过，这些神经足细胞可以触发大脑中多巴胺的释放，让你想继续吃更多的东西。

And we talked about how these neuropod cells can signal the release of dopamine in circuits within the brain to cause you to seek out more of something.

现在，很符合逻辑的是，多巴胺也参与了呕吐这个过程。

Now, in a very logically consistent way, dopamine is also involved in the whole business of vomiting.

你可能会想，这说不通啊。

You might think, well, that doesn't make any sense.

我一直以为多巴胺是好事。

I thought dopamine was always a good thing.

它跟动机和奖励什么的有关。

It's involved in motivation and reward, etcetera.

但事实上，脑干里的这个呕吐中枢——最后区，布满了多巴胺受体。

But turns out the area postrema, this vomit center in the brainstem is chockablock full of dopamine receptors.

如果多巴胺水平过高，确实会引发呕吐。

And if dopamine levels go too high, it can actually trigger vomiting.

这在治疗帕金森等疾病的药物中就能看到。

And this we see in the context of various drugs that are used to treat things like Parkinson's.

帕金森病通常是因为多巴胺不足或者多巴胺神经元缺失，导致静止性震颤和行动困难，因为多巴胺也跟很多控制运动的神经回路有关。

Parkinson's is a deficiency in dopamine or a lack of dopamine neurons typically that causes a resting tremor, difficulty in movement, because dopamine is also associated with a lot of the neural circuits for movement.

很多治疗帕金森的药物，比如左旋多巴，会大幅提高多巴胺水平，或者至少在某些脑区强烈激活多巴胺受体，结果可能触发呕吐反应。

Many drugs that are used to treat Parkinson's like L DOPA increase levels of dopamine so much, or at least activate dopamine receptors to such a great degree in certain areas of the brain that they can cause activation of things like the trigger to vomit.

这其实在自然情境下也说得通。如果你拼命吃，拼命吃，拼命吃，你肠道里那些感知营养的神经元只是在检测营养的存在，它们自己并不会做决定。

Now, this should also make sense in the natural context of if you gorge yourself with food, gorge yourself with food, gorge yourself with food, the neurons in your gut that respond to that are simply detecting the presence of nutrients, but they don't really make decisions themselves.

它们不知道什么时候该停下来。

They don't know to stop eating.

你的大脑才知道该停止进食，或者把食物排出去。

Your brain knows to stop eating or to eject that food.

所以，这些神经元能跟大脑区域沟通，不仅包括那些促进继续进食的区域，还包括像最后区这样的区域，当多巴胺水平过高时，就会让我们停止吃那种食物，或者通过呕吐把食物排出来，这真是件好事。

And so it's a wonderful thing that those neurons are communicating with areas of the brain, not just that stimulate consuming more food, but that are communicating with areas of the brain, for instance, area postrema, that when dopamine levels get too high, cause us to either stop eating that food or in the case of vomiting to eject that food.

我提这个，不是想给你一个恶心的反例来对比我们所说的“食欲行为”——那些我们想多做点的事情，而是想让你明白，就连我们觉得是恶心、呕吐，或者想找更多食物这样的反射，其实都是被一种推拉系统控制的，由来自肠道的平行通路来调节。

So I raise this and not to give you a kind of a disgusting counter example to what we call appetitive behaviors, the things that we like to do more of, but simply to give you a sense of just how strongly even these reflexes that we think of as feeling sick and vomiting, or the desire to seek out more food are really being controlled by a kind of push pull system, by parallel pathways that are arriving from our gut.

同样的神经化学物质，这里就是多巴胺，被用来产生两种相反的行为：一种是继续吃，另一种是把已经吃进去的全部排出来。

And the same neurochemicals, in this case dopamine, are being used to create two opposite type behaviors, one behavior to consume more, one behavior to get rid of everything you've already consumed.

所以，我们的大脑其实对来自肠道的信号量很敏感，而不仅仅是信号传递的路径。

So our brain is actually sensitive to the amount of signaling coming from our gut, not just the path by which that signal arrives.

我们的大脑会非常仔细地关注，被触发的多巴胺水平是否处于正常进食行为的范围内，或者我们是否已经吃得太多，以至于足够了。

Our brain is very carefully paying attention to whether or not the levels of dopamine that are being triggered are within a normal range for typical eating behavior, or whether or not we've gorged ourselves to the point where enough already.

当然，机械信号也会影响最后区和呕吐反射。

Now, of course, mechanical signals will also play into area postrema and into the vomiting reflex.

如果我们的肠道过度扩张，我们会感到不舒服，甚至可能非常痛苦，并且会有呕吐的欲望，或者直接呕吐。

If we have a very distended gut, we feel lousy, it actually can hurt very badly and we will have the desire to vomit or we will just simply vomit.

机械信号和化学信号总是并行到达的。

Mechanical and chemical signals are always arriving in parallel.

它们从来不会同步工作。

They never work in unison.

现在我们已经讨论了化学信号和机械信号，接下来我想谈谈直接和间接信号，因为到目前为止我讲的大部分都是直接信号，也就是神经通路汇聚到大脑，产生特定的感觉、想法或行为，但还有间接通路。

And so now we have chemical signals, mechanical signals, and now I'd like to talk about direct and indirect signals because almost everything I've talked about up until now are direct signals, a neural pathway that converges in the brain to create a particular feeling, thought, or behavior, but there are also indirect pathways.

这就把我们带回了肠道微生物组和那些微小的微生物。

And that's what takes us back to the gut microbiome and to these little microbiota.

我先在这里给大家一个核心结论，然后再详细讲讲它是怎么来的。

And to just give you the takeaway message at the front here, and then I'll give you a little more detail as to how it comes about.

你的大脑、脊髓、眼睛和周围神经系统里都有神经递质，它们能激活或抑制神经活动，也就是说，它们要么让其他神经细胞变得活跃，要么让它们变得不那么活跃。

You have neurotransmitters in your brain and in your spinal cord and in your eyes and in your peripheral nervous system, they cause the activation or the suppression of nerve activity, meaning they either electrically activate other nerve cells or they cause other nerve cells to be less electrically active.

它们是通过神经递质来实现的。

And they do that by way of neurotransmitters.

但事实证明，肠道微生物群能够影响代谢过程，在某些情况下，它们自己也能合成神经递质。

But as it turns out, the gut microbiota are capable of influencing metabolic events and in some cases are capable of synthesizing neurotransmitters themselves.

所以这意味着，这些小小的细菌，这些肠道里的微生物，那六磅重的货物，它们实际上能制造出神经化学物质，这些物质可以进入血液，进入大脑，间接影响你身体和大脑的其他细胞。

So what that means is that these little bugs, these little microbiota that are cargo in your gut, the six pounds of cargo, they actually can make neurochemicals that can pass into the bloodstream and into your brain and actually impact the other cells of your body and brain indirectly.

而不需要经过我们刚才讨论的那些复杂的神经通路。

So without involving these very intricate nerve pathways that we've been talking about.

换句话说，你吃的食物，你的肠道微生物环境，实际上能创造出化学基础，让你的大脑感觉好或坏，让你追求某种行为或回避某种行为。

In other words, the foods you eat, the environment of your gut microbiome can actually create the chemical substrates that allow your brain to feel one way or the other, to feel great or to feel lousy, to seek out more of a particular type of behavior or to avoid that behavior.

这就是所谓的间接信号。

And that would constitute indirect signaling.

所以我一直在讲很多关于肠道到大脑通路的结构和功能，主要关注进食行为，有时候也涉及避免进食，甚至把食物从消化道里排出去。

So I've been talking a lot about the structure and function of the gut to brain pathway, focusing mainly on feeding behaviors and in some cases avoiding feeding or even ejecting food from the digestive tract.

我想更深入地探讨一下从肠道到大脑的间接信号通路，因为它能很好地连接我们从肠道到大脑的神经元信号、激素信号，还包括我们节目一开始提到的微生物组。

I'd like to drill a little bit deeper into this indirect signaling pathway from the gut to the brain, because it bridges us nicely from neuronal signals in the gut to the brain, hormonal signals from the gut to the brain, to what also includes the microbiome, which is what we started talking about at the beginning of the episode.

就像我几分钟前提到的，某些肠道微生物实际上可以合成某些神经递质，这些神经递质可以影响大脑。

As I mentioned a couple of minutes ago, certain gut microbiota can actually synthesize certain neurotransmitters that can go impact the brain.

而且我们确实知道哪些微生物可以合成特定的神经递质。

And we actually have some knowledge about which microbiota can synthesize particular neurotransmitters.

比如说，神经调节物质多巴胺可以由芽孢杆菌和沙雷氏菌合成。

For instance, the neuromodulator dopamine can be synthesized by or from bacillus and ceratia.

这些只是微生物的名字。

Now, these are just names of microbiota.

我不指望你们谁一定认识它们。

I don't expect that any of you would necessarily recognize them.

这些不是那种你会特意去买来增加多巴胺的东西。

These aren't the sorts of things that you necessarily would run out and buy to get more dopamine.

但重点是，特定的肠道微生物可以在我们的肠道里产生多巴胺，这些多巴胺能进入血液，从而普遍改变我们大脑和身体其他部位的基线多巴胺水平。

But the point is that particular gut microbiota can create dopamine in our gut that can get into our bloodstream and can generally change our baseline levels of dopamine within the brain and other areas of the body.

我提到基线多巴胺水平，是因为我在一期专门讲多巴胺的节目里详细讲过，但这里我简单重复一下基本概念。

I mentioned baseline levels of dopamine because as I talked about on an episode all about dopamine, but I'll just repeat the basics here now.

我们有神经递质或神经调节物质的基线水平，就像潮水的基准线，然后通过行为、摄入特定食物或药物等，可以产生多巴胺的峰值。

We have baseline levels of neurotransmitters or neuromodulators that act as sort of the level of the tide, the overall level, and then we can have peaks of dopamine that are created by behaviors or by ingestion of particular foods or drugs, etcetera.

所以，芽孢杆菌和柠檬酸杆菌倾向于提高我们的基线多巴胺水平。

So bacillus and ceratia tend to increase our baseline levels of dopamine.

如果我们能营造出合适的肠道微生物环境，让这些特定的肠道微生物得以繁衍，那么我们的基线多巴胺水平就会升高。

So if it turns out that we are creating the right gut microbiome environment that these particular gut microbiota can thrive in, well, then our baseline levels of dopamine will be elevated.

总的来说，这有助于改善情绪。

And in general, that leads to enhancement of mood.

同样，还有其他肠道微生物，比如念珠菌、链球菌、各种肠球菌，这些名字总是有点奇怪，不太吸引人，至少对我这个神经生物学家来说是这样。

Similarly, there are other gut microbiota, for instance, Candida, Streptococcus, various enterococcus, these always have these kind of strange and not so attractive names, at least to me as a neurobiologist.

尽管如此，这些特定的微生物支持血清素的产生，甚至可以被代谢成血清素，而血清素是一种与情绪、社交互动以及大量不同类型的事件和行为相关的神经调节物质。

Nonetheless, those particular microbiota support the production of, or can even be metabolized into serotonin, which is a neuromodulator associated with mood, with social interactions, with a huge number of different types of events and behaviors.

再说一遍，当这些肠道微生物存在并在我们的肠道中茁壮成长时，它们会提高我们整体的血清素水平，而在这个血清素水平之上，还会有因特定行为而释放的血清素。

Again, these gut microbiota when present and allowed to thrive in our gut will increase our overall levels of serotonin and riding on top of that level of serotonin will be the serotonin that's specifically released in response to certain behaviors.

我真的想强调一下基线和峰值这个观点。

And I really want to drive home this point of baselines and peaks.

血清素的基线水平可能决定了我们的整体情绪，比如我们醒来时是感觉不错还是非常糟糕，如果血清素水平非常低的话，我们是否倾向于处于平静状态，还是容易烦躁。

The baseline level of serotonin might set our overall mood, whether or not we wake up feeling pretty good or really lousy if our serotonin levels happen to be very, very low, whether or not we tend to be in a kind of a calm space or whether or not we tend to be somewhat irritable.

但当然，在我们一天中遇到的各种事件，比如得到别人的赞美，或者有人说了一些让我们恼火的话，不管是什么，也会影响血清素水平，但这些血清素的变化与大脑中特定神经回路的活动有关。

But then of course, individual events as we go about our day, maybe a compliment that we get, or maybe somebody says something irritating to us, whatever it may be will also influence levels of serotonin, but those serotonin events are going to be related to events at particular neural circuits in the brain.

这是一个重要的话题，因为我觉得很多人听到一个说法，而且这个说法很准确，就是90%到95%的血清素是在肠道里产生的。

And this is an important topic because I think that a lot of people hear quite accurately, oh, 90 to 95% of our serotonin is manufactured in the gut.

确实如此，这些血清素是由我刚才描述的那些微生物产生的。

And indeed that's true, it's manufactured from the sorts of microbiota that I just described.

现在有很多实验，主要是在动物模型上，但也有一些在人类身上进行的实验，表明如果肠道微生物组缺乏这些特定细菌，血清素水平就会下降，人们的情绪会受到影响，甚至可能影响免疫系统功能，甚至可能加重某些精神疾病。

And there are many, many experiments now, mostly in animal models, but also some in humans that show that if the gut microbiome is deficient in some way to these particular bacteria, that serotonin levels drop and people's mood suffers, maybe even their immune system functions, maybe even exacerbates certain psychiatric illnesses.

然而，很多人因此认为大脑中的血清素全部或大部分来自肠道。

However, a lot of people take that to mean that the serotonin of the brain all comes from the gut or mostly comes from the gut.

事实并非如此。

That's not the case.

大脑中的神经元仍然会直接对某些事物做出反应，比如社交接触或其他积极的社交体验，释放血清素。

It's still the case that you have neurons in the brain that are responsible for releasing serotonin directly in response to certain things like social touch or through other types of positive social experiences.

所以，我们肠道中的微生物群确实可以被转化为多巴胺，并提高我们的多巴胺基线水平。

So we've got gut microbiota that can literally be turned into dopamine and raise our baseline levels of dopamine.

我们肠道中的微生物群确实可以提高我们的血清素基线水平。

We've got gut microbiota that can literally raise our baseline levels of serotonin.

确实还有其他肠道微生物，比如乳酸杆菌或双歧杆菌，抱歉，这些名字很难发音，双歧杆菌，它们可以增加GABA水平，这种抑制性神经递质可以起到一点温和镇静的作用，减少烦躁等。

And indeed there are other gut microbiota like lactobacillus or bifidobacterium, excuse me, hard complex names to pronounce, bifidobacterium that can give rise to increases in GABA levels, this inhibitory neurotransmitter that can act as a little bit of a mild sedative, can reduce irritability, etcetera.

但这只是基线，是这些神经调节物质的潮汐。

But that's just the baseline, the kind of tide of those neuromodulators.

再次强调，我们的大脑和身体中仍然有神经回路，它们会以非常有效的方式释放多巴胺、血清素和GABA。

Again, I want to emphasize that we still have neural circuits within the brain and body that are specifically releasing in a very potent way dopamine, serotonin, and GABA.

所以这两者是协同作用的。

So the two things act in concert.

尽管肠道和大脑既在并行运作，又直接相互影响，但这是一个强大的协同效应。

Even though the gut and the brain are acting both in parallel and directly influencing one another, it is a powerful synergistic effect.

现在有数百项研究，甚至可能已经上千项了，大多是在动物模型上做的，通常是小鼠，但也有一些人体研究，表明为这些肠道微生物创造合适的生存环境确实能提升情绪和幸福感。

And there are now hundreds of studies, maybe even thousands by this point, mostly performed in animal models, typically mice, but also some studies in humans that show that creating the correct environment for these gut microbiota to thrive really does enhance mood and well-being.

而当肠道微生物组不健康时，确实会削弱我们的情绪和幸福感。

And that when our gut microbiome is not healthy, that it really can deplete our mood and sense of well-being.

那么，要建立健康的肠道微生物组，主要有两个阶段。

Now, there are two major phases to creating a healthy gut microbiome.

一个是你能够控制的，另一个则不太受你控制。

One you can control and the other one is less under your control.

我在与医生的那期节目里详细讲过这些。

I get into this in a lot of detail in the episode with Doctor.

就是紧接着这一期之后播出的那期，也就是下周一。

Sonnenberg, which is coming out immediately after this one, the following Monday that is.

但现在，我只想简单提几个关于肠道微生物组早期建立的关键点。

But for now, I want to just capture a few of the main points about the early establishment of the gut microbiome.

事实证明，我们接触的环境、与皮肤、消化道以及其他黏膜表面接触的东西，甚至尿道、鼻腔，任何与外界相通的开口，都会在生命的前三年带来某些微生物，这对我们体内能携带的微生物种类会产生深远的影响。

It turns out that the environment that we are exposed to, the things that come into contact with our skin and digestive tract and any other mucosal lining, even the urethra, the nasal passages, any opening to the outside world that brings in certain, excuse me, certain microbiota in the first three years of life is going to have a profound impact on the overall menu of microbiota that we will be able to carry within our body.

而且，在头三年里接触并建立多样化的微生物组，确实看起来至关重要。

And it really does seem that getting exposure to and building a diverse microbiome in those first three years is critical.

有很多猜测和一些数据表明，剖腹产出生的婴儿相比顺产出生的婴儿，微生物组的多样性较低。

There's a lot of speculation and some data as to cesarean delivered babies having less diverse microbiomes compared to vaginally delivered babies.

有人尝试将这一点与自闭症谱系障碍联系起来，虽然还没有定论，但至少根据一些统计数据，剖腹产婴儿患自闭症的概率似乎更高，不过也有其他研究反驳这一点，我想明确说明这一点。

There've been attempts, although not conclusive attempts to link that to the presence of autism spectrum disorders, which at least by some statistics seem to be of higher probability in cesarean deliveries, although there are other studies that refute that, and I want to make that clear.

然而，很明显，婴儿在子宫内接触到的微生物很少，甚至几乎没有，可能有一点，但不多。真正建立肠道微生物组是在出生过程中以及出生后的几天和几周内，那时肠道微生物开始在肠道内定居。

However, it's clear that babies do not get much, if any exposure to microbiota inside of the womb, maybe a little bit, but not much, but that is during the birth process and then the days and weeks immediately after they arrive in the world that their gut microbiome established, that those gut microbiota take residence within the gut.

所以，这取决于婴儿是母乳喂养还是奶瓶喂养。

So it will depend on whether or not they were breastfed or bottle fed.

这还取决于他们是否接触过家里的宠物，是否被多个照顾者抱过，还是只有一个，以及他们是否是早产儿，是否被放在特别限制的环境中，以促进他们进一步发育，然后才能回家。

It will depend on whether or not they were exposed to a household pet or not, whether or not they were held by multiple caregivers or just by one, whether or not they were a preemie baby and were contained in a particularly restrictive environment in order to encourage their further development before they could be brought home or not.

我不想给大家留下这样的印象：如果你被隔离或者剖腹产出生，你的微生物组就注定不好。

I don't want to give the picture that if you were isolated or you were delivered by C section, that you're somehow doomed to have a poor microbiome.

事实并非如此。

That's simply not the case.

不过，早期建立更多样化的微生物群，确实对长期健康有好处，无论是大脑和肠道之间的信号传递，还是免疫系统的功能。

However, it is the case that the more diversity of microbiota that one can create early in life is really helpful for long term outcomes in terms of brain to gut signaling, gut to brain signaling, and for sake of the immune system.

有一些可靠的研究表明，如果儿童在早期大量使用抗生素，可能会严重破坏健康肠道微生物群的建立。

There are some decent studies showing that if children are exposed to a lot of antibiotic treatment early in life, that can be very detrimental to establishment of a healthy gut microbiome.

幸运的是，重新建立健康的肠道微生物群可以帮助弥补这些不足。

And fortunately that reestablishing a healthy gut microbiome can help rescue some of those deficits.

所以现在的医生在给儿童开抗生素时更加谨慎了，不仅是在三岁之前，甚至到五岁、七岁、十岁都是如此。

So doctors nowadays are much more cautious about the prescription of antibiotic drugs to children in their early years, not just up to three years, but extending out to, you know, five and seven and 10 years.

即使是成年人，他们也非常非常小心，或者说应该如此。

And even in adults, they're very, very careful about that, or they ought to be.

其中一个原因是抗生素耐药菌的存在，或者说扩散，这些细菌在医院和其他地方越来越常见，可能引发严重问题。

One reason is the existence, or I would say the proliferation of antibiotic resistant bacteria that are becoming more common in hospitals and elsewhere, and that can cause serious problems.

但除此之外，我们还了解到，肠道微生物群会影响甚至产生神经递质，这些神经递质能影响情绪和心理健康，以及免疫健康等。

But in addition to that, because of this understanding that the gut microbiome is influencing and actually creating neurotransmitters that can impact mood and mental health, impact immune health and so on.

正如我之前提到的，有数百甚至数千项研究强调了微生物组对大脑健康、精神健康等方面的重要作用。

As I mentioned earlier, there are hundreds, if not thousands of studies emphasizing the key role of the microbiome on brain health, psychiatric health, etcetera.

我想重点提几项研究，特别是那些来自长期从事这方面研究的实验室的最新成果。

I want to just highlight a few of those studies and in particular, recent studies that come from labs that have been working on this sort of thing for a very long time.

其中一项令人兴奋的研究来自贝勒医学院的毛罗·科斯塔·马蒂奥利实验室。

One of the more exciting studies comes from the work of Mauro Costa Matioli's lab, which is at Baylor College of Medicine.

毛罗的实验室长期以来一直在用小鼠模型研究自闭症谱系障碍，并观察其社交行为。

Mauro's lab has been working on mouse models of autism spectrum disorder for a long time and looking at social behavior using a mouse model for a long time.

他们发现，某些特定类型的微生物在肠道中定植后，能够缓解自闭症的一些症状，至少是在这些小鼠模型中表现出的症状，明白吗？

And they've been able to identify particular types of microbiota that when they take resonance in the gut can help offset some of the symptoms of autism, at least the symptoms of autism that exist in these mouse models, okay?

再说一次，这不是人体研究。

So again, this is not human work.

之所以用小鼠模型，是因为可以进行这类操作，比如让小鼠处于无菌环境或非无菌环境，或者让它们接触特定的微生物而不接触其他微生物。

This is work being done on mouse models for the simple reason that you can do these kinds of manipulations where basically they took mice that were in germ free environments or non germ free environments, or they exposed mice to particular microbiota and not other microbiota.

他们发现一种叫做L的特定微生物。

And they discovered that a particular microbiota called L.

罗伊氏乳杆菌，就是L。

Rueteri, it's L.

R E U T E R I，用L治疗。

R E U T E R I, treatment with L.

罗伊氏乳杆菌能纠正这些自闭症模型中的社交缺陷。

Rueteri corrects the social deficits present in these autism models.

它是通过激活我们的老朋友——迷走神经来实现的，但不仅仅是因为迷走神经触发多巴胺释放，而是因为这种特定的肠道微生物L。

And it does so by way of activating our old friend, the vagus nerve, but not simply because the vagus nerve triggers the release of dopamine, but it turns out that this particular gut microbiota, L.

罗伊氏乳杆菌能纠正这种自闭症谱系障碍模型中的社交缺陷。

Rudery, can correct the social deficits in this autism spectrum disorder model.

它是通过迷走神经通路，同时刺激多巴胺和催产素的释放来实现的。

It does that by way of a vagal nerve pathway that stimulates both dopamine release and oxytocin release.

他们通过实验证明了这一点，比如，如果去掉催产素受体，这种改善效果就消失了。

And they establish this really mechanistically by showing, for instance, if you get rid of the oxytocin receptor, you don't see this rescue.

这些是小鼠模型，所以我们需要谨慎看待，但它们确实令人兴奋，而且与其他研究相辅相成，这些研究将患有某种疾病或没有某种疾病的人的微生物组移植到患有某种疾病或另一种疾病的人身上。

Now those are mouse models, so we have to take those with the appropriate grain of salt, but they're really exciting and they come to us in parallel with other studies that are being done, taking the microbiomes of people who have one condition or lack of condition and putting it into people who have one condition or another condition.

让我解释一下我是什么意思。

Let me explain what I mean by that.

早期关于肠道微生物组及其对健康潜在影响的发现，并不是在肠道到大脑的通路背景下，而是在结肠炎的背景下。

The early discovery of the gut microbiome and its potential to impact health was not in the context of the gut to brain pathway, but rather was in the context of colitis.

这可以追溯到50年代的研究，当时患有非常严重且顽固性结肠炎、其他治疗都无效的患者接受了粪便移植。

This dates back to studies in the 50s, whereby people with very severe intractable colitis for which no other treatment was going to work received fecal transplants.

是的，正如听起来那样，就是取没有结肠炎的健康人的粪便，移植到患有结肠炎的人的下消化道中，他们看到了显著的改善，甚至可以说是治愈了结肠炎。

So yes, that's exactly as it sounds, taking the stool of healthy people who do not have colitis, transplanting those stools into the lower digestive tract of people who do have colitis, and they saw significant improvement, if not rescue of the colitis.

这是最早的迹象之一，表明粪便中的某些东西竟然能治愈另一个人的疾病，这听起来有点疯狂，可能对你们有些人来说还觉得恶心。

That was one of the first indications that something within stool of all things could actually rescue another individual from disease, which sounds kind of wild and crazy and may sound disgusting to some of you.

但正如我在节目开头提到的，粪便中近60%是活菌或死菌，也就是微生物群，这确实开启了一个全新的领域，探索不同的微生物如何产生治疗效果。

But as I mentioned at the beginning of the episode, almost 60% of stool is live or dead bacteria, microbiota, and it really opened up this entire field of exploring how different microbiota might have therapeutic effects.

事实上，粪便移植在某些精神疾病的治疗中也已被证明有效。

And indeed that has been shown to be the case also in fecal transplants for certain psychiatric illnesses.

这些研究仍在进行中。

These are still ongoing studies.

这些研究的质量参差不齐。

They vary in quality.

这些研究做起来很难，原因有很多，比如要找合适的病人群体、获得同意等等，还要确保所有环节都处理得当。

These are hard studies to do for all sorts of reasons, getting the appropriate patient populations, getting agreement, etcetera, making sure that everything's handled properly.

但这种方法就是把没有特定精神疾病或代谢疾病的人的粪便，移植到有特定代谢疾病的人体内。

But what this involves is fecal transplants from individuals that lack a particular psychiatric condition or metabolic condition into people who have a particular metabolic condition.

在某些案例中，效果非常显著。

And there has been tremendous success in some cases.

其中一个最有说服力、最典型的例子就是肥胖症。

One of the more powerful and salient examples is for obesity.

有些人即使摄入极低的热量，甚至只吃流质蛋白饮食，也减不了肥。

There are some people for which, even if they ingest very low numbers of calories, even if they go on a liquid protein diet, can't lose weight.

这些是比较罕见的疾病，但这些人要么选择做胃绕道手术。

These are somewhat rare disorders, but these are people that would either do get gastric bypass surgery.

现在有些人会接受来自健康体重者的粪便移植，把他们的粪便植入自己的下消化道，结果发现，那些原本无法减肥的人，体重有了显著下降。

Some people are now getting these fecal transplants from people that have healthy weight and they take the stool from them, they put it into lower digestive tract and they can see substantial improvement in weight loss in people that were otherwise unable to do that.

实际上，有些情况下，他们甚至可以开始吃相对正常的食物量，体重还是会下降。

In some cases actually, they can start eating relatively normal levels of food and still lose weight.

所以这真的很了不起。

So pretty remarkable.

这告诉我们，这些微生物群中有些东西非常强大。

And that tells us there's something in these microbiota that's really powerful.

不过，这些效果是如何产生的，目前还不清楚。

Now, how those effects are generated isn't clear.

一种观点是，它影响了代谢组的成分，几乎可以肯定就是这样。

One idea is that it's impacting the metabolome components of the metabolism, almost certainly that's going to be the case.

另一种观点是，它影响了神经递质，从而改变大脑中的行为和食物选择。

Another idea is that it's impacting neurotransmitters, which change behavior and food choices within the brain.

不过，正如我提到的，有些人一开始就吃得很少。

Although, as I mentioned, some of these people are already eating very little food to begin with.

所以这个论点就有点难成立了。

So that's a little bit harder of an argument to create.

现在也有一些比较有名的例子，说明粪便移植可能导致负面结果，但这些负面结果反而进一步证明了微生物组对身体健康的影响力。

There are also some somewhat famous examples now of how fecal transplants can lead to negative outcomes, but those negative outcomes further underscore the power of the microbiome in impacting bodily health.

一个典型的例子是，为了治疗结肠炎之类的疾病，把粪便移植到另一个人体内，效果确实不错。但如果粪便捐赠者本身是肥胖或者有其他代谢综合征，那么接受者也可能因为接受了捐赠者的特定微生物群而患上同样的代谢综合征。

One key example of this, for instance, is transfer of fecal matter into another person in order to treat something like colitis, and it effectively does that, but if the donor of the stool, of the fecal matter happened to be obese or have some other metabolic syndrome, it's been observed that the recipient can also develop that metabolic syndrome simply by way of receiving that donor's particular microbiota.

所以这些微生物群既能带来好的结果，也可能带来坏的结果。

So these microbiota can create positive outcomes or they can create negative outcomes.

当然，我们大多数人并不感兴趣，也不会去做粪便移植。

Now, most of us of course are not interested in or pursuing fecal transplants.

大多数人只是想建立一个健康的肠道微生物环境，以支持免疫系统和大脑功能。

Most people are interested in just creating a healthy gut microbiome environment for sake of immune system and brain function.

我们几分钟后就会讨论如何做到这一点。

And we will talk about how to do that in just a few minutes.

但我还想进一步强调微生物群在塑造大脑化学以及情绪和其他心理健康方面的重要性，而这些通常我们不会和肠道联系起来。

But I just want to further underscore the power of the microbiota in shaping brain chemistry and in shaping things like mood or other aspects of mental health that typically we don't associate with our gut.

近年来发表了几项研究。

There are several studies published in recent years.

我特别想提一篇研究，第一作者是Tanya Nguyen，拼写是N G U Y E N。

One that I'll just highlight now, first author, it's Tanya Nguyen, N G U Y E N.

论文的标题是《孤独感和智慧与肠道微生物多样性和组成的关系：一项探索性研究》。

The title of the paper is Association of Loneliness and Wisdom with Gut Microbial Diversity and Composition, an exploratory study.

这项研究很有意思，调查了184名社区居住的成年人，年龄从28岁到97岁不等。

It's an interesting study looked at 184 community dwelling adults, excuse me, ranging from 28 to 97 years old.

他们想看看，肠道微生物多样性更高，是否和所谓的孤独感、智慧这些因素有关。

They explored whether or not having enhanced microbial diversity somehow related to these variables that they refer to as loneliness and wisdom.

他们用了好几种不同的测试来评估这些因素。

They used a number of different tests to evaluate those.

这些测试在心理学研究里很常见，生物学研究里用得不多，但确实能用来衡量孤独感和智慧。

Those are common tests in the psychology literature, not so much in the biology literature, but nonetheless, are ways of measuring things like loneliness and wisdom.

在这项研究里，智慧被看作是孤独感的对立面。

Wisdom in this case being the opposite of loneliness, at least in the context of this study.

结果发现，微生物多样性越高，也就是肠道菌群越多样，孤独感的发生率就越低。

And what they found was microbial diversity, the more diverse one's microbiome was, the lower incidence of loneliness.

他们是通过采集粪便样本，分析其中的RNA，基本上就是对这些人的粪便进行基因测序，然后评估他们感到孤独或不孤独的程度，并将这些数据关联起来。

And they did this by taking fecal samples, profiling them for RNA, so essentially doing gene sequencing of the stool of these individuals, getting ratings of how lonely or not lonely they felt and correlating those.

这只是一项研究而已。

And that's just but one study.

我特别提到它，是因为这项研究比较新，而且看起来做得特别好。

I pointed out because it's particularly recent and it looked like it was particularly well done.

还有另一项研究，我在这里提一下。

There is another study that I'll just refer you to.

这项研究发表在2020年的《科学报告》上。

This was a study published in 2020 in Scientific Reports.

研究的标题是《情绪幸福感与肠道微生物组按肠型分类的概况》。

The title of the study is Emotional Well-being and Gut Microbiome Profiles by Enterotype.

我特别喜欢这项研究的地方在于，他们能够将某些微生物的存在与主观幸福感以及抑郁症状的有无关联起来。

What I particularly like about this study is that they were able to correlate the presence of certain microbiota with feelings of subjective well-being and lack of or presence of depressive symptoms.

他们对个体的微生物组进行了高通量基因测序。

They did high throughput gene sequencing of the microbiomes of individuals.

所以这意味着要测量微生物群，弄清楚存在哪些微生物，以及它们的微生物组总体上有多多样，肠道微生物组的多样性是件好事。

So that meant measuring the microbiota, figuring out which microbiota were present, how diverse their microbiome was in general, gut microbiome diversity is a good thing.

然后把这些与所谓的PANAS评分关联起来。

And then to correlate that with what's called the PANAS score.

PANAS代表积极情感和消极情感量表。

PANAS stands for positive affect, negative affect schedule.

这是一个我的实验室广泛使用过的测试，其他实验室也用它来评估情绪和幸福感。

This is a test that my lab has used extensively that other labs use to evaluate mood and well-being.

他们定义了三种所谓的肠型，也就是三类饮食差异很大的人，他们往往在负面情绪症状上更多或更少，或者在正面情绪症状上更多或更少，以及他们是否更容易抑郁、焦虑，或者有更多与压力相关的行为等等。

And they defined what were called three enterotypes, three different categories of people that ate very different diets that tended to fall into categories of having more or fewer emotional symptoms that were negative or more or fewer emotional symptoms that were positive, and whether or not they tend to be more depressed, anxious, or have more stress related behaviors, etcetera.

从这项研究中，他们得出了一些有力的线索，告诉我们应该在饮食中摄入哪些东西，甚至可能应该避免某些东西，但肯定的是，我们应该摄入哪些类型的食物来提升情绪和幸福感，并帮助人们远离抑郁、焦虑和压力相关的症状。

And what they were able to derive from this study was some strong indications about what types of things we should ingest in our diet, maybe even certain things that we should avoid, but certainly the types of things that we should ingest that can enhance mood and well-being and can tend to shift people away from more depressive like anxiety and stress related symptoms.

在我们讨论具体哪些食物有助于健康的微生物组之前，我想提出一个更大、也许更重要的问题，那就是：什么是健康的微生物组？

Before we get into what the particular food items were that lend themselves to a healthy microbiome, I want to raise a bigger and perhaps more important issue, which is what is a healthy microbiome?

我觉得如果你问任何一位世界级专家，我当然也问过博士。

I think if you asked any number of world experts, and I certainly asked this of Doctor.

索南伯格博士，什么是健康的微生物组？

Sonnenberg, what is a healthy microbiome?

他们都会告诉你，健康的微生物组具有很高的多样性，包含很多不同种类的细菌。

They're all going to tell you it's a microbiome that has a lot of diversity, that includes a lot of different types of bacteria.

这很合理，因为从逻辑上讲，它应该包含能产生GABA、多巴胺和血清素的细菌，这些细菌还能支持免疫系统，并发挥多种其他作用。

And that makes sense because it logically would include the bacteria that produce GABA and dopamine and serotonin and that support the immune system and do a number of different things.

但仅仅增加微生物多样性就总是好事吗？

But is it simply the case that adding microbiota diversity is always a good thing?

嗯，事实似乎并非如此。

Well, that doesn't seem to be the case.

益生菌和益生元都能增加微生物多样性，改善情绪、消化、免疫系统等。

Probiotics and prebiotics, both of which can enhance microbiota diversity, can improve mood digestion, immune system, and so on.

这一点已经得到证实，但主要是在抗生素治疗后、疾病恢复期、压力大或面临各种身心挑战的人群中，用于补充肠道微生物组。

That's been established, but it's mainly been established in the context of post antibiotic treatment or people that are recovering from illness or people that have been very stressed or have been dealing with all sorts of challenges, mental or physical, and they are an attempt to replenish the gut microbiome.

然而，过量摄入益生菌导致微生物过度增长，也可能引发脑雾等问题。

However, it's also clear that excessive microbiota brought about by excessive intake of probiotics can lead to things like brain fog.

实际上，有一些不错的研究表明，微生物组的某些代谢产物，也就是肠道和身体里产生的某些化学物质，确实可能导致脑雾状态。

There's actually some good studies that point to the fact that certain metabolites of the microbiome, certain chemicals produced in the gut and in the body can actually lead to brain fog states.

这被认为是通过肠道的乳酸途径产生的，然后这些途径会影响大脑。

This is thought to come about through the lactate pathways of the gut that can then impact the brain.

如果你想进一步了解过量服用益生菌是否可能导致脑雾这个问题，我建议你看看一篇特定的论文。

If you want to look more into this issue of whether or not probiotics taken in excess perhaps can lead to brain fog, I'd encourage you to look at a particular paper.

这篇论文发表在《临床与转化胃肠病学》杂志上。

This is a paper published in Clinical and Translational Gastroenterology.

论文的标题是《脑雾、胀气和腹胀：SIBO、益生菌和代谢性酸中毒之间的联系》。

And the title of the paper is Brain Fogginess, Gas and Bloating, A Link Between SIBO, Probiotics and Metabolic Acidosis.

它发表于2018年。

It was published in 2018.

我们可以提供这项研究的链接。

We can provide a link to this study.

参考文献中还有其他几项研究也指出，在某些情况下，过量摄入益生菌和肠道菌群过度增殖实际上可能是有问题的。

And there are several other studies in the references that point to the fact that in some cases, excessive intake of probiotics and excessive proliferation of gut microbiota can actually be problematic.

我提这个不是为了让你困惑，而是因为外面的信息确实很混乱。

I mentioned this not to confuse you, but because it is confusing out there.

我们都以为增加肠道菌群的多样性总是好事，但凡事都有个度，超过一定限度，菌群过度多样可能反而有问题。

We all would think that just increasing microbiota diversity is always a good thing, but there are thresholds beyond which excessive microbiota diversity might be problematic.

我想大家都同意，体内微生物种类太少肯定不是好事。

I think everyone agrees that having too few microbial species living in us is not a good idea.

不过，这些都没回答大家真正想知道的问题，那就是：我们该怎么做？

Now, none of that answers the questions that I think everyone really wants answers to, which are, what should we do?

为了改善肠道菌群，我们不该做什么？

What should we not do to improve our gut microbiome?

显然，我们没法穿越回零到三岁的时候，去养条狗、接受母乳喂养，或者选择顺产而不是剖腹产，如果当时没那个条件的话。我们真的没法穿越回去做这些。

I mean, clearly we can't time travel back to when we were zero to three years old and get a dog if we didn't have a dog, get breastfed if we weren't breastfed, be delivered vaginally as opposed to by C section if we didn't have that opportunity, we just can't time travel and do that.

但不管怎样，我们都应该努力改善肠道菌群的状态，因为它对大脑和全身健康的影响太关键了。

All of us, however, should be seeking to improve the conditions of our gut microbiome because of the critical ways in which it impacts the rest of our brain and bodily health.

那我们到底该怎么做呢？

So what should we do?

那哪些事情我们不应该做呢？

What shouldn't we do?

显然，要知道压力会对肠道微生物群产生负面影响。

Clearly, know that stress can negatively impact the gut microbiome.

不过，有些所谓的会对微生物群产生负面影响的压力形式，包括禁食，长时间禁食，这说得通，因为很多微生物需要食物才能生存。

However, some forms of stress that can quote unquote negatively impact the microbiome include fasting, long periods of fast, which makes sense because a lot of microbiota need food in order to thrive.

事实上，很多微生物，甚至可以说所有微生物，在某个阶段都需要食物。

In fact, many, if not all of them do at some point.

还有其他问题，比如，我们应该吃特定的食物吗？多久吃一次这些食物？

There are other questions such as, should we eat particular foods and how often should we eat those foods?

我们一直听说纤维非常重要，因为含有益生元纤维，基本上可以喂养微生物群，但纤维真的有必要吗？它对促进健康的微生物群有多重要？

We've all been told that fiber is incredibly important because of the presence of prebiotic fiber, which can essentially feed the microbiome, but is fiber really necessary and how necessary is it to encourage a healthy microbiome?

显然，有很多人遵循相对低碳水化合物的饮食，比如生酮饮食，这些饮食在某些情况下可能具有抗炎效果，有时也能改善某些微生物物种。

Clearly, there are a number of people following relatively low fiber diets, such as ketogenic diets, and those can have, in some cases, anti inflammatory effects and can sometimes also improve certain microbiota species.

所以这一切可能相当令人困惑。

So it can all be rather confusing.

为此，我问了我们常驻的专家，博士。

And for that matter, I asked our resident expert, Doctor.

斯坦福的贾斯汀·索南伯格，所有这些问题，他在接下来的一集里系统地回答了。

Justin Sonnenberg at Stanford, all of these questions, and he answers them very systematically in the episode that comes out after this one.

但我不想对你有所保留，所以我会先给出一个非常概括的答案版本，然后你会在那一集中得到更深入的答案。

But I don't want to withhold anything from you, so I'll just give a very top contour version of those answers, and then you'll get more in-depth answers during that episode.

我问了关于禁食的问题。

I asked about fasting.

我问禁食的原因是，多年前，我参加了一个皮尤生物医学学者会议，其中另一位生物医学学者是肠道微生物组的专家。

And the reason I asked about fasting is that years ago, I was at a meeting as part of the Pew Biomedical Scholars meeting, and one of the other few biomedical scholars was an expert in gut microbiome.

我说，嘿，益生菌对微生物组有好处吗？

And I said, Hey, are probiotics good for the microbiome?

如果有，我应该吃哪一种？

And if so, which one should I take?

他的回答非常有趣。

And his answer was very interesting.

他说，你知道，在某些情况下它们是有用的，特别是当你旅行或者压力大的时候，但事实证明，大多数益生菌里含有的特定细菌，其实并不能补充你最需要的那种微生物群。

He said, you know, in certain cases they can be, especially if you're traveling or you're stressed, but it turns out that the particular bacteria that they put in most probiotics don't actually replenish the microbiota that you need most.

然后我就想，哦，那他们为什么不生产那种能补充你最需要的微生物群的益生菌呢？

And I thought, oh, well, why don't they make ones that replenish the microbiota that you need most?

他的回答是，他们不直接补充那些，但他们补充其他的，这些其他的细菌反过来会促进你想要的微生物群的生长，只要你开始吃合适的食物。

And his answer was, well, they don't replenish those, but they replenish other ones that then in turn encourage the development of the microbiota that you do want once you start eating the appropriate foods.

所以他们改变了环境，让环境变得更好，从而间接地支持了所谓“好”微生物的繁殖。

So they change the environment, which makes the environment better, which indirectly supports the proliferation of quote unquote good microbiota.

好吧，这个回答有点绕，但我还是感谢他的回答。

Okay, so that was a somewhat convoluted answer, but I did appreciate his answer.

然后我问他关于禁食的问题。

Then I asked him about fasting.

我说，现在很多人开始对间歇性禁食感兴趣了。

I said, well, a lot of people are getting interested in intermittent fasting now.

人们每天二十四小时里，有相当一部分时间不吃东西，就是为了进行限时进食。

People are spending a significant portion of each twenty four hour cycle avoiding food for sake of time restricted feeding.

那对肠道微生物群有什么影响？

What does that do to the gut microbiome?

是让它更健康还是更不健康？

Does it make it healthier or does it make it unhealthier?

嗯，我在耶鲁的同事和桑嫩伯格博士都确认了。

Well, my colleague from Yale and Doctor.

在禁食期间，尤其是长时间禁食，我们实际上会开始消化掉自己消化道的很大一部分。

Sonnenberg both confirmed that during periods of fasting, especially prolonged periods of fasting, we actually start to digest away much of our digestive tract.

当然，整个消化道不会消失，但黏膜层会变薄，或者至少会受到破坏。

Now the whole thing doesn't start to disappear, but there's thinning of the mucosal lining, or at least disruption of the mucosal lining.

很多微生物物种可能会开始死亡。

A lot of the microbiota species can start to die off.

所以这让我很惊讶，但尽管如此，禁食实际上可能会破坏肠道菌群中某些健康成分，这很有趣。

And so it was surprising to me, but nonetheless interesting that fasting may actually cause a disruption to certain healthy elements of the gut microbiome.

但话说回来，这里有个前提条件。

But again, there's a caveat.

但需要注意的是，人们在禁食后进食时，可能会出现补偿性增殖，也就是健康的肠道微生物群会增加。

The caveat is that when people eat after a period of fast, there may be a compensatory proliferation, meaning an increase in healthy gut microbiota.

所以你可以开始明白，禁食既不好也不坏。

So you start to get the picture that fasting is neither good nor bad.

你也会开始明白，特定的饮食，比如某些限制性饮食或富含宏量营养素的饮食，对微生物群来说可能也不是好或坏。

You start to get the picture that particular diets, meaning certain restriction diets or macronutrient rich diets may not be good or bad for the microbiome.

然而，有一些答案来自索尼伯格医生，

And yet there are some answers that arrive to us from Doctor.

也来自该领域的其他专家，那就是有些食物和我们可以摄入的东西，确实能增强微生物群，使其比不摄入这些食物时更健康。

Sonnenberg, but from other experts in the field, that there are certain foods and certain things that we can ingest, which definitely enhance the microbiome and make it healthier than it would be were we to not ingest those foods.

接下来，我想谈谈我认为在这个领域里一项真正开创性和重要的研究。

So next I'd like to talk about what I think is a really pioneering and important study in this area.

这项研究由索尼伯格实验室与斯坦福的克里斯·加德纳实验室合作进行，他们比较了人类饮食中的两种主要类型：富含纤维的饮食，这种饮食一再被提出可以增强微生物群的多样性，甚至增强肠脑信号，也可能增强免疫系统；以及富含所谓低糖发酵食品的饮食。

This is a study that was carried out by the Sonnenberg Lab in collaboration with Chris Gardner's Lab, also at Stanford, where they compared two general types of diets in humans, diets that were fiber rich, which has been proposed time and time again to enhance microbiota diversity and to enhance gut brain signaling even, and to enhance the immune system perhaps, and diets that were enriched in so called low sugar fermented foods.

在我深入探讨这项研究及其结论之前，因为这些结论很有趣且对我们所有人都非常实用，我想先谈谈益生菌，因为我想避免混淆。

Before I dive into that study and what the conclusions were, because they interesting and very actionable for all of us, I do want to touch on probiotics because I want to avoid confusion.

并不是说摄入益生菌就一定会导致脑雾。

It is not the case that ingestion of probiotics will always lead to brain fog.

我想把这点说清楚。

I want to make that clear.

事实上，即使益生菌本身不直接含有你想要增殖的那种菌群，摄入益生菌也可能有助于提高肠道菌群的多样性。

It is the case that ingestion of probiotics, even if those probiotics don't directly contain the microbiota species that one is trying to proliferate, can be useful for improving microbiota diversity.

总的来说，维持健康的肠道微生物组似乎需要摄入某些类型的食物，我们稍后会谈到这些食物，但也许还需要通过低剂量的益生元或益生菌来持续地增强微生物组系统。

In general, it seems that maintaining a healthy gut microbiome involves ingesting certain types of foods, and we'll talk about those in a moment, but perhaps also augmenting the microbiome system through prebiotics or probiotics at a fairly low level on a consistent basis.

所以这些不是高剂量的益生菌，除非在菌群失调的情况下，比如有人服用了一轮抗生素后需要补充肠道微生物组，这时有一些食物以及片剂和粉末形式的益生元和益生菌会非常有用。

So these are not high dose probiotics except under conditions of dysbiosis, where for instance, if somebody has done a round of antibiotics and they need to replenish their gut microbiome, there are foods and there are pill form and powder form prebiotics and probiotics that can be very useful.

或者当人们压力很大、旅行频繁或饮食发生剧烈变化时。

Or in cases where people have been very stressed or are undergoing excessive travel or have shifted their diet radically.

也许是因为旅行，也许是因为生病，也许是因为压力，但当多种不同的事件同时发生，给微生物组多样性带来压力或使其减少时，至少我认为通过摄入优质益生菌或益生元来支持肠道微生物组是有用的。

Maybe that's due to travel, maybe that's due to illness, maybe that's due to stress, but when there are a number of different converging events that are stressing or depleting microbiota diversity, that's when, at least I believe it can be useful to support the gut microbiome through the ingestion of quality probiotics or prebiotics.

所以，在人们感到压力或身体系统因环境或疾病原因而普遍受压的情况下，可能需要比平时更高剂量的益生元或益生菌，但在正常情况下，应该通过饮食关注优质营养素，并以较低到中等水平摄入益生菌和益生元。

So it would be under conditions where people are stressed or their system is generally stressed for environmental or illness related reasons, that it might be useful to lean towards higher doses of prebiotics or probiotics than one might normally use, but that under normal conditions that one would focus on quality nutrients through diet and focus on ingestion of probiotics at a fairly low to moderate level and or prebiotics at a fairly low to moderate level.

这看起来就是基于我咨询过的专家们得出的合理做法，但当然，如果你的医生出于任何原因给你开了高剂量的益生菌，或者建议你服用，你一定要听从医生的建议，显然要听医生的。

That just seems like the logical approach based on the experts that I've spoken to, but certainly if your doctor prescribes or suggests that you take high levels of probiotics for any reason, you should definitely pay attention to your physician and you should obviously pay attention to your physician.

无论如何，在没有咨询医生的情况下，你不应该随意添加或删除营养计划或补充计划中的任何东西。

In any case, you should never add or remove anything from your nutritional plan or supplementation plan without consulting a physician.

那么，为了最大化我们所谓的“肠脑轴”的健康，我们应该怎么做呢？

So what should we do in order to maximize the health of our gut brain axis as it's called?

我们应该如何支持有益微生物的多样性，这些微生物帮助我们产生所需的各种神经递质，改善我们的免疫系统功能等等。

How should we support the diversity of the good microbiota that help us create all these neurotransmitters that we want, improve our immune system function and so on and so forth.

嗯，其中一部分要依靠基础的东西。

Well, some of that is going to be through the basics.

我说的基础，是指那些真正为我们的整体健康打下基础的根本性事项。

When I say the basics, I mean the foundational things that really set us up for overall health.

这包括保证充足的高质量深度睡眠，80%以上的时间都要做到。

So this is going to be getting deep sleep of sufficient duration 80 plus percent of the time.

我的意思是，如果你能100%做到，那当然很好，但很少有人能做到。

I mean, if you could get a 100% of the time, that'd be great, but very few people accomplish that.

还要保证充足的水分摄入。

It's going to be proper hydration.

还要有正常的社交互动。

It's going to be proper social interactions.

还要有合理的营养。

It's going be proper nutrition.

关于营养，我们稍后会详细讨论。

And we'll talk more about nutrition in a moment.

还要避免长期过度的压力或应激。

It's going to be limiting excessive prolonged stressors or stress.

实际上，关于这些方面我们都已经做过节目了，特别是关于压力，我们在Huberman Lab播客中有一集，你可以在hubermanlab.com找到，专门讲如何掌控压力，如何避免长时间的高强度压力，以及如何应对这些压力。

And indeed, we've done episodes about just about all of those things, but certainly about stress, we have an episode of the Huberman Lab Podcast that you can find at hubermanlab.com, all about mastering stress, how to avoid long periods of intense stress, what to do to offset those.

既然压力会扰乱肠道菌群，无论你是否在禁食，这些方法都应该有用。

Given that stress can disrupt the microbiome, whether or not you're fasting or not, those tools ought to be useful.

现在，我认为有一项具有里程碑意义的研究，探讨了肠道菌群、食物摄入和整体健康之间的关系，那就是来自斯坦福大学的Justin Sonnenberg实验室和Chris Gardner实验室的论文。

Now, in what I consider to be a landmark study exploring the relationship between the gut microbiome, food intake, and overall health is this paper from Justin Sonnenberg's lab and Chris Gardner's lab, both of which are at Stanford.

这篇题为《肠道微生物靶向饮食调节人体免疫状态》的论文发表在《细胞》杂志上，该杂志可能是全球三大顶级期刊之一，《自然》、《科学》和《细胞》确实是整体科学尤其是生物医学领域的顶尖期刊。

And the paper entitled gut microbiota targeted diets modulate human immune status was published in the journal Cell, which is among the three top journals perhaps in the world, Nature, Science, and Cell really being the apex journals for overall science and especially for biomedical sciences.

这是一项非常有趣的研究。

Now, this is a very interesting study.

研究对象是人类。

It was done on humans.

研究分为两大组。

There were two major groups.

其中一组被要求增加饮食中的纤维摄入量，实际上他们确实吃了高纤维饮食。

One group of humans was instructed to increase the amount of fiber in their diet, and in fact, ate a high fiber diet.

另一组被要求吃高发酵食品饮食。

The other group was instructed to eat a high fermented food diet.

两组参与者一开始都没有摄入大量纤维或发酵食品，他们被要求在四周的逐步增加期内提高纤维或发酵食品的摄入量。

Now, both groups started off not having eaten a lot of fiber or a lot of fermented foods, and were told to increase the amount of either fiber or fermented foods that they were ingesting over a four week ramp up period.

这样做是为了避免任何严重的肠胃不适。

And that was to avoid any major gastric distress.

事实证明，如果你平时不习惯吃很多纤维，突然大幅增加纤维摄入量可能会导致一些肠胃不适。

It turns out that if you're not already accustomed to eating a lot of fiber, increasing your amount of fiber dramatically can cause some gastric distress.

但如果你慢慢适应，就像我们接下来会看到的，这项研究揭示了背后的机制，如果你循序渐进，身体系统就能承受。

But if you ease into it over time, as we'll see, there's a mechanism behind this, which was unveiled in this study, but if you ease into it over time, then the system can tolerate it.

同样，高发酵食品如果有一个逐步增加的过程，比如先从每天一份开始，然后每天两份，逐步增加到每天六份，也容易耐受。

Likewise, high fermented foods can be readily tolerated if there's a ramp up phase of ingesting maybe one serving a day, then maybe two servings and ramping up in this case as high as six servings per day.

然而，在适应期之后，高纤维组维持高纤维饮食六周，高发酵食品组维持高发酵食品饮食六周，之后他们停止高纤维或高发酵食品饮食。

However, after this ramp up period, the group assigned to the high fiber condition maintained high fiber intake for six weeks and the high fermented food group maintained high fermented food intake for six weeks, after which they went off either the high fiber or the high fermented food diet.

然后有四周的随访期，期间他们逐渐恢复到基线水平。

And there was a four week follow-up period during which they gradually returned to baseline.

在整个研究过程中，他们评估了肠道微生物组的多样性。

Throughout the study, their gut microbiome was evaluated for the diversity of gut microbiota.

同时，还测量了多项免疫系统功能指标，特别是所谓的炎症组。

And there were also a number of measures of immune system function, in particular measures of the so called inflammatome.

免疫系统涉及很多不同的分子。

The immune system has a lot of different molecules involved.

我之前做过一整期关于免疫系统的节目。

I did a whole episode about the immune system.

如果你有兴趣了解那些分子是什么，比如各种细胞因子和信号分子，它们反映的是大脑和身体里炎症水平高还是低，欢迎去看那一期。

If you're interested in learning what some of those molecules are, various cytokines and signaling molecules that reflect either high inflammation states or reduced inflammation states in the brain and body, you're welcome to check out that episode.

节目也在hubermanlab.com上。

It's also at hubermanlab.com.

总之，在这项研究中，他们观察了两组人各自表达的免疫标志物，并进行了比较。

Regardless, in this study, they explored the sorts of immune markers that were expressed in either of the two groups and compared those.

这篇论文的基本结论是，与他们的预期相反，高纤维饮食并没有导致肠道菌群多样性增加，至少不是在所有情况下都如此。

The basic takeaway of this paper was that contrary to what they predicted, the high fiber diet did not lead to increased microbiota diversity, at least not in all cases.

这有点出乎意料。

And that was somewhat surprising.

你知道，通常认为益生元纤维以及水果、蔬菜、谷物中的很多成分应该能支持菌群多样性，促进现有菌群的增殖。

You know, the idea is that prebiotic fiber and a lot of the material in fruits and vegetables and grains and so forth are supposed to support microbiota diversity and the proliferation of existing microbiota.

但他们观察到的并不是这样。

And that is not what they observed.

不过我要特别说明一下，这个结果并不意味着纤维对整体健康没用，但它确实说明，增加纤维摄入并没有增加微生物多样性，而一般来说，像我之前提到的，微生物多样性与微生物功能、健康和整体幸福感的改善有关。

Although I want to be very clear in pointing out that the results did not indicate that fiber is not useful for health overall, but it does point to the fact that increasing fiber intake did not increase microbiota diversity, which in general, as I mentioned before, is associated with improvements in microbiota function, health, and overall well-being.

接下来，高发酵食品饮食组的情况非常有意思。

Now, the high fermented food diet condition was very interesting.

它导致了微生物多样性的增加，以及炎症信号和活动的减少。

It resulted in increased microbiome diversity and decreased inflammatory signals and activity.

所以基本上是一举两得，就是大量摄入发酵食品，对吧？

So there was a twofer, basically by ingesting high fermented foods in fair abundance, right?

你知道，每天四到六份甚至更多，这算是摄入量很大的发酵食品了。

You know, four to six servings or more per day is a lot of fermented food intake.

我们稍后会聊聊具体是哪些食物，但结果是非常积极的。

We'll talk about what some of those foods were, but the outcome was very positive.

微生物多样性明显增加，炎症信号也减少了。

There was a clear increase in microbiome diversity and decreased inflammatory signals.

比如白细胞介素六，以及其他一些与大脑和身体炎症增加相关的白细胞介素和细胞因子，都显著降低了。

So things like interleukin six, a number of other interleukins and cytokines that are associated with increased inflammation in the brain and body were reduced significantly.

现在，我们稍微聊聊这个份数的概念之类的。

Now, let's talk a little bit about this notion of number of servings, etcetera.

这项研究有一个小点，但我觉得对采取行动很有用，那就是发酵食品的份数并不是预测炎症组改善（即炎症减少和微生物多样性提升）的强指标，而个体摄入发酵食品的持续时间才是。

One somewhat minor point of the study, but I think is useful in terms of taking an actionable stance with this, is that the number of servings of fermented foods was not as strong a predictor of improvements in the inflammatome, meaning reduced inflammation and improvements in microbiota diversity, as was the duration of time that the individuals were ingesting fermented foods.

换句话说，一个人每天持续摄入发酵食品的时间越长，肠道微生物组和抗炎效果就越好。

In other words, the longer that one is consistently ingesting fermented foods on a daily basis, the better the outcomes in terms of the gut microbiome and for reducing inflammation.

所以我觉得这一点很重要。

So I think that's an important point.

我特别强调这一点，是因为对很多人来说，即使你有个逐步增加的过程，每天六份发酵食品听起来也很多。

And I make that point, especially because for a lot of people, even if you do this ramp up phase, six servings per day of fermented foods can seem like quite a lot.

那么，这些发酵食品是什么呢？

So what are these fermented foods, right?

我想很多人都熟悉某些奶酪是发酵的，啤酒是发酵的，康普茶也是发酵的。

I think many of us are familiar with certain cheeses and being fermented and beer being fermented and kombucha is fermented.

在这项研究中，他们特别关注低糖发酵食品。

In this study, they focus specifically on low sugar fermented foods.

所以就是原味酸奶，有些情况下还有泡菜或酸菜。

So this would be plain yogurt, in some cases, kimchi or sauerkraut.

不过，有一个重要的考虑因素，就是这些食物必须含有所谓的活性益生菌，也就是说酸菜里面实际上得有活着的微生物。

An important consideration, however, is that it needs to contain what are called live active cultures, which means there actually have to be microbiota that are alive inside the sauerkraut.

一个判断方法就是，如果你从超市非冷藏货架或非冷藏区买的罐装酸菜、泡菜或腌黄瓜，那里面肯定没有活性的益生菌。

One way you know whether or not that's happening is if you purchase sauerkraut or pickles or kimchi from a jar or a container that's on the non refrigerated shelf or the non refrigerated section of your grocery store, it is not going to contain live active cultures of microbiota.

同样，如果你喝的酸奶含糖量高或者加了其他成分，它对肠道菌群的正面影响也会大打折扣。

And likewise, if you consume yogurt that has a lot of sugar or other components added to it, it's not going to have the same positive effect on the microbiome.

至少根据含糖酸奶和原味酸奶中微生物种类的差异，可以做出这样的预测。

At least that's the prediction given some of the relationship between the sorts of microbiota that live in sugar versus plain type yogurts.

他们让参与者可以选择各种不同的低糖发酵食品。

They gave people the option of consuming any number of different low sugar fermented foods.

所以，可以是酸菜、泡菜，还有像开菲尔、纳豆这样的东西，在日本人们吃纳豆，那也是一种发酵食品。

So again, that could be sauerkraut, kimchi, things like kefir, natto, in Japan, they consume natto, which is a fermented food.

啤酒不在他们列出的发酵食品名单里。

Beer was not one of the fermented foods that was included in the fermented food list.

当我们说每天六份时，那确实是指六盎司一份，或者四到六盎司一份。

And when we say six servings per day, that is indeed six ounce servings or six four to six ounce servings.

不是包装上列出的六份。

It was not six servings of what's listed on the package.

所以，这实际上就是相当多的发酵食品。

So again, that turns out to be a fair amount of fermented foods.

你该怎么判断自己是否摄入了足够的量呢？

How should you gauge whether or not you're getting enough of this?

如果你决定采用这个增加发酵食品摄入的方案，至少根据我对这项研究以及正在进行的一些后续工作的理解，这听起来是个很棒的主意。

Well, if you decide to take on this protocol of ingesting more fermented foods, which at least by my read of this study and some of the follow-up work that's being done, sounds like a terrific idea.

如果你想改善肠道微生物组，为了那些大家都想追求的好处，比如大脑和身体健康、减少炎症等等，那你肯定要专注于你喜欢的发酵食品。

If you want to improve your gut microbiome for all the great reasons that one would want to, brain, body health, reduced inflammation, and on and on, Well, then you definitely want to focus on fermented foods that you enjoy consuming.

所以，对你来说，如果那是开菲尔，或者对你来说是原味酸奶，或者对你来说是酸菜，那恰好是我个人的最爱，那你就要确保它会是你喜欢大量摄入的东西，而且你愿意在一天中持续摄入。

So for you, if that's kefir or for you, that's plain yogurt, or for you, that's sauerkraut, which happens to be my personal favorite, then you want to make sure that it's going to be something that you are going to enjoy ingesting quite a lot of and that you're going to be okay with ingesting probably throughout the day.

当然，每个人的用餐时间表不同，但这确实要求你不仅仅是在睡前或某一餐中吃掉所有发酵食品。

Now, people follow different meal schedules, course, but this does require not just eating all the fermented foods just before bedtime or at one meal.

我想你也可以那样做，但一般来说，分散到一天中吃效果最好，能减少肠胃不适。

I suppose you could do that, but in general, it's going to work best in terms of limiting gastric distress by spreading it out throughout the day.

我还想提一下盐水。

I also want to mention brine.

盐水就是泡酸菜的那个液体。

Brine is the liquid that surrounds sauerkraut.

就是那种很咸的液体，里面含有大量活性益生菌。

It's that very salty fluid, and that contains a lot of active live cultures.

在这项研究中，他们确实允许人们把盐水也算进去。

And they did include, or they allowed people to include brine in this study.

在和博士的讨论中，

And in discussions with Doctor.

我们下周会详细聊那期节目，我们谈了很多关于盐水在促进微生物多样性方面的特殊价值，因为它富含活性益生菌。

Sonnenberg, which we'll go into in more detail on the episode that comes out next week, we talk a lot about the particular value that brine might hold in terms of bringing about microbiota diversity because of the richness of live cultures that it contains.

我想花点时间讲讲高纤维组，因为对那组人有一些有趣的观察。

I do want to focus for a moment on the high fiber condition because there were some interesting observations about the people that were placed into that condition.

首先，增加纤维摄入量确实提高了那些能用于消化纤维的酶的数量。

First of all, increasing the amount of fiber definitely increased the number of enzymes that can be used to digest fiber.

这符合所谓的‘适应期’概念：随着纤维摄入量的逐渐积累，长期来看不仅能减轻胃部不适，还能提高身体对纤维的利用率，这整体来说是个好事。

This is in keeping with this idea of this ramp up phase where accumulation of more fiber intake can over time to less gastric distress, but also to more utilization of fiber, which overall should be a good thing.

虽然他们没有观察到免疫功能或微生物多样性的提升，但这些有助于消化纤维的酶确实增加了。

So while they didn't observe an increase in immune system function or an increase in microbiota diversity, there was an increase in these fiber digesting enzymes.

他们还观察到了所谓的‘个性化免疫反应’。

They also observed what they called personalized immune responses.

在高纤维组里，有一些亚群在炎症反应方面出现了有趣的变化。我说的炎症反应，指的是他们体内表达的炎症标志物，以及肠道菌群的多样性。

There were some subgroups within the high fiber group that had interesting changes in terms of their reactions to, or I should say their inflammatome, meaning the inflammatory markers they expressed as well as their microbiota diversity.

所以基本上分成了三组。

So there were essentially three groups.

其中一组人的炎症标志物反而升高了。

One group actually showed an increase in inflammatory markers.

这挺让人意外的，也可能不太利于‘纤维对所有人都有好处’这个观点的传播，不过这只是高纤维摄入组里的一个小群体。

So that was quite surprising and probably not wonderful for the message that fiber is always good for us, but that was a small cohort within the fiber intake group.

另外两组，虽然程度不同，但都表现出基线微生物多样性的下降。

Another group and still another group both showed reductions in baseline microbiota diversity, although to varying degrees.

所以我不想把纤维说成是坏的，但纤维确实没有像高发酵食品饮食那样对微生物多样性产生积极影响。

So I don't want to paint the picture fiber is bad, but fiber certainly did not have the positive effects on microbiota diversity that the high fermented food diet did.

所以我对这项研究的解读，也是很多人基于这些数据得出的结论，就是我们应该增加发酵食品的摄入，这是支持肠道微生物组、减少大脑和身体炎症信号的好方法。

So my read of this study, and I think the stance that many others have taken as a consequence of these data, is that we should be increasing our fermented food intake, that that's simply a good thing to do in order to support our gut microbiome and to reduce inflammatory signals in our brain and body.

有很多不同的方法可以做到这一点。

And there are a number of different ways to do that.

我之前提到了一些具体的食物。

I mentioned some of the particular foods.

不过，当你谈论摄入发酵食品时，尤其是那些来自杂货店冷藏区的高品质、低糖产品，我们确实需要考虑成本，因为像康普茶这样的东西可能相当昂贵。

However, anytime you're talking about ingesting fermented foods, especially the high quality ones that come from the refrigerated section of the grocery store, end that have low sugar content, etcetera, we do have to be considerate of cost because certain things like kombuchas, for instance, can be quite costly.

我还应该提到，有些康普茶实际上含有酒精，有些则不含，或者含量非常低。

I should also mention some kombuchas actually contain alcohol, some do not, or contain very little amounts of alcohol.

一个避免发酵食品高成本的方法，同时又能大量摄入发酵食品，就是自己动手制作这些发酵食品。

One way to avoid the high cost of fermented foods while still being able to accumulate a lot of fermented food intake is to simply make those fermented foods yourself.

这也是我们家里已经开始尝试和探索的事情。

And this is something that we've started exploring and experimenting with in our home.

一个简单的办法就是自己做酸菜。

One simple way to do this is to just make your own sauerkraut.

需要的食材很少。

It involves very few ingredients.

基本上就是卷心菜、水和盐，但要想在家用低成本的方法做出大量的酸菜，你需要遵循一个特定的流程。

It basically involves cabbage, water, and salt, but there's a specific process that you need to follow in order to create these large volumes of sauerkraut at home using that low cost method.

我知道的最好的自制酸菜食谱，是蒂姆·费里斯在《四小时厨师》那本书里提供的。

The best resource that I know of in order to follow a great recipe to make homemade sauerkraut would be the recipe for homemade sauerkraut that's contained in Tim Ferriss' book, The Four Hour Chef.

那里有一个非常棒的步骤。

There's an excellent protocol there.

这个过程包括把卷心菜切碎，放进碗里，用手揉搓，这还挺好玩的，然后加水、加盐，盖上盖子，放在特定的环境里，还要定期把表面的东西刮掉。

It involves chopping up the cabbage, putting into a bowl, mashing it up with your hands, which can be fun, putting water in there, some salt, covering it, and then keeping it in a particular environment, and then routinely scraping off some of the material from the surface.

这样做是为了确保不会长出对你有害的微生物或其他东西。

You have to do that in order to make sure that you're not getting microbes and things growing in it that are bad for you.

所以你一定要仔细按照步骤来，但这是非常非常低成本的方法来制作大量的发酵食品，这样你就不用为了改善肠道菌群而花光积蓄。

So you definitely want to pay careful attention to the protocol, but that's a very, very low cost way of generating lots and lots of fermented foods so you don't go broke trying to improve your microbiome.

如果你真的很喜欢康普茶，想避免它的高成本，还有别的办法。你可以弄到SCOBY，这样基本上就能在家自己做康普茶了。

The other thing that you can do if you're really obsessed with kombucha or something like that to avoid the high cost of kombucha is there are ways that you can get the SCOBY, which basically allows you to make your own kombucha at home.

我从来没试过，但当我做博士后的时候，实验室里有个本科生，我就不点名了，他现在已经上了医学院，我觉得他已经完成了住院医师培训，现在是个执业医生了。不过，他总是在家做康普茶。

I've never tried this, but when I was a postdoc, there was an undergraduate in the lab, think, won't out him, but he's now gone on to medical school and I think he's passed his residency and is a practicing doctor, but nonetheless, he was always making kombucha at home.

他跟我说这特别简单，但话说回来，他有很多其他技能和特质，让我觉得他几乎什么都能轻松搞定，而我连基本的做饭都费劲。

He told me it was exceedingly easy, but then again, he had a number of other skills and attributes that made me think that he could do pretty much anything with ease, whereas I tend to struggle with even basic cooking.

所以，如果你觉得更有冒险精神，可以试试自己做康普茶，不过网上有很多不同的方法和食谱，可以自己做低糖发酵食品。

So maybe if you're feeling a little more adventurous, could explore making your own kombucha, but there are a number of different protocols and recipes out there for making your own low sugar fermented foods.

所以你不需要老是跑出去买新鲜的酸菜。

So you needn't run out and buy fresh sauerkraut all the time.

我还想提一下，那些想通过吃泡菜来摄入发酵食品的人，罐装泡菜很少含有发酵成分。

I should also mention for those of you that are interested in getting your fermented intake from pickles, jarred pickles rarely if ever contain ferment.

大多数只是泡在醋水里，加了些香料，但也有一些确实含有发酵成分。

Mostly they're just soaked vinegar water and with some spices, but there are some that contain ferment.

你得在包装上找找看有没有标注。

You actually have to look for that on the container.

而且我不知道，也许有人知道怎么做纳豆，也知道怎么做泡菜之类的。

And I don't know, maybe someone out there knows how to make natto and knows how to make kimchi well and things of that sort.

根据研究数据，确实每天摄入更多份发酵食品对肠道微生物组是有益的。

It certainly is the case based on the data from the study that ingesting more servings of fermented food per day ought to be beneficial for our gut microbiome.

既然这一集不只是关于肠道微生物组，还涉及肠道与大脑健康，我应该提一下肠道微生物组和大脑之间的一种信号传递方式，我们之前没讨论过，我就简单提一下：当炎症组或炎症相关基因和标志物保持在健康范围内时，免疫系统的状态会主动向大脑传递信号。

And since this is an episode, not just about gut microbiome, but gut brain health, I should mention that one form of signaling between the gut microbiome and the brain, which we did not discuss, and I'll just touch on briefly, is that when the inflammatome or the genes and markers of inflammation are kept in a healthy range, there's an active signaling of that immune system status to the brain.

有一种中间细胞类型负责把免疫状态传递给大脑，这种细胞就是小胶质细胞，从名字就能看出，它是一种胶质细胞。

There's an intermediate cell type that communicates immune status to the brain, and that cell type is the microglial cell, it's a type of glia as the name suggests.

当身体里炎症很多时，这些小胶质细胞会被激活，开始侵蚀大脑和神经系统的各种组成部分。

When there's a lot of inflammation in the body, these microglia actually get activated and can start eating away at various components of the brain and nervous system.

我不是说它们会大量侵蚀，它们不会把整个大脑消化掉，但这些小胶质细胞就像是大脑里的常驻巨噬细胞。

And I don't mean massive eating away, they're not going to digest the whole brain, but these microglia are sort of the resident macrophages of the brain.

巨噬细胞在外周，它们会吞噬碎片之类的东西。

Macrophages are in the periphery and they gobble up debris and things of that sort.

小胶质细胞平时会清理在清醒周期中积累的碎片，以及大脑每天因微小损伤产生的垃圾。

The microglia on a regular basis are eating up debris that accumulates across waking cycles and in response to micro damage of the brain that occurs on a daily basis.

所以它们有很多重要的日常基础功能，我们称之为“管家功能”。

So they have a lot of important basic everyday, what we call housekeeping functions.

但是当身体有大量炎症，或者出现强烈的免疫反应时，小胶质细胞可能会过度激活，这被认为会导致各种认知缺陷或思维困难，甚至可能随着时间推移引发某些神经退行性疾病。

But when there's a lot of inflammation in the body, when there's a massive immune response, the microglia can be hyper activated and that's thought to lead to any number of different cognitive defects or challenges thinking, or maybe even some forms of neurodegeneration over time.

不过最后这一点目前更多是假设，而不是确凿的事实，还需要在人类身上做大量研究。

Although that last point is more of a hypothesis than a well tamped down fact at this point, there's still a lot of investigation to be done in humans.

动物数据非常非常有力，表明当免疫系统被激活、长期激活或过度激活时，神经组织——也就是脑组织和其他中枢神经系统组织——可能会受损。

The animal data, are very, very strong that when the immune system is activated or chronically activated or hyperactivated, that neural tissue, meaning brain tissue and other central nervous system tissue can suffer.

所以有很多理由不仅要改善微生物组的多样性，还要改善免疫系统功能，并减少体内炎症标志物的数量，因为这些炎症标志物会向大脑传递有害信号。

So there are a lot of reasons to want to not just improve microbiome diversity, but to also improve immune system function and to limit the number of inflammatory markers that are present in the body because of the way those inflammatory markers can signal deleterious events in the brain.

虽然吃发酵食品、自己制作发酵食品或购买高品质发酵食品可能看起来有点麻烦。

And while eating fermented foods and making your own fermented foods and buying high quality fermented foods might seem like an inconvenience.

但我想说，从成本效益或努力效益的角度来看，这其实是个不错的选择。如果你能在几周内逐渐增加每天吃的发酵食品或发酵食品的份量，让自己适应良好，那对你的微生物组多样性，甚至对肠道-大脑功能，都会有非常积极的影响。

I would say that from the perspective of cost benefit or effort benefit, it's actually quite a good situation where if you can just ramp up the number of fermented foods that, or servings of fermented foods that you're eating per day over a period of a few weeks so that you're tolerating that well, that ought to have a very positive effect on your microbiome diversity and indeed on gut brain function.

而且我绝不会建议大家完全不吃纤维。

And I'll be the last to suggest that people completely forego on fiber.

我觉得关于我们需要多少纤维，以及某些类型的纤维是否比其他类型更好，还存在一些争议。

I think there's some debate out there as to how much fiber we need and whether or not certain forms of fiber are better than others.

我不打算参与这个争论。

I'm not going to get into that debate.

这个话题已经够棘手了，我就不掺和自己的观点了。但我认为有充分的证据表明，对大多数人来说，摄入适量的纤维是个好主意。

It's barbed wire enough without me injecting my own views into that debate, but I think there's ample evidence to support the fact that for most people ingesting a fair amount of fiber is going to be a good idea.

我只想说，确保你同时也摄入适量的发酵食品。

I would just say that make sure that you're also ingesting a fair amount of fermented foods.

关于纤维，在《细胞》杂志上发表的配套文章中，也就是我们所说的关于Sonnenberg和Gartner那篇论文的新闻与观点文章，他们提出了一个很好的观点：纤维摄入量的增加导致了碳水化合物活性酶的增加，这些酶被称为CAZymes，它们有助于消化纤维，这表明微生物组降解纤维食物中复杂碳水化合物的能力增强了。

And along the lines of fiber, in an accompanying article published in Cell, which was sort of a, what we call a news and views piece about the Sonnenberg and Gartner paper, they make a quite good point, which is that the increase in fiber intake that led to this increase in carbohydrate active enzymes, these CAZzymes as they're called, these are enzymes that help digest fiber, indicating an enhanced capacity for the microbiome to degrade complex carbohydrates present in fibrous foods.

所以换句话说，多吃纤维和纤维性食物，可以增加这些酶的数量，从而让你能够吃更多的纤维性食物，或者更好地消化来自其他来源的纤维性食物。

So in other words, eating more fiber and fibrous foods allowed for an increase in these enzymes that allow you to eat still more fibrous foods or to better digest fibrous foods that are coming in through other sources.

所以，增加纤维摄入至少有一个好处，尽管这与肠道微生物多样性和减少炎症无关。

So there is at least one utility for increasing fiber, even though it's separate from the gut microbiota diversity and reducing inflammation.

如果我不提一下关于人工甜味剂和肠道微生物组的一些数据和争议，那我就太失职了。

And I'd be remiss if I didn't touch on some of the data and controversy about artificial sweeteners and the gut microbiome.

我想说清楚，我接下来要讲的这些，至少据我所知，只在动物模型，也就是小鼠模型中得到过验证。

I want to be very clear that what I'm about to tell you has only been established in animal models, in a mouse model, at least to my knowledge.

这些研究，有好几项，但其中一项几年前发表在《自然》杂志上的研究最受关注，它表明，大量摄入人工甜味剂，特别是像糖精或三氯蔗糖这类物质，会导致动物肠道微生物组出现紊乱。

What the studies have shown, and there were several, but one published in the journal Nature a few years back is the that got the most amount of attention, is that animals that consume large amounts of artificial sweeteners, in particular things like saccharin or sucralose, show disruptions in their gut microbiome.

据我所知，目前还没有在人类身上发现类似效应的研究，也没有关于植物性低热量甜味剂，比如甜菊糖、罗汉果之类的东西，在人类身上有同等效应的研究。

I'm not aware of any studies in humans that show the equivalent effect, and I'm not aware of any studies in humans that show the equivalent effect for things like plant based low calorie sweeteners, things like stevia, monk fruit, and things of that sort.

而且至少就我查到的资料来看，我找不到任何专门针对阿斯巴甜这种甜味剂的相关数据。

And at least by my exploration, I couldn't find any data specifically related to the sweetener aspartame.

所以现在这个问题有点争议，而且这其实是个敏感话题。当有人说人工甜味剂不好，因为它们会破坏肠道微生物组时，通常会有很多人回应说，这只是在动物模型里得到验证，事实也确实如此。

So right now it's somewhat controversial and actually this is kind of a third rail topic out there when one group will come out saying that artificial sweeteners are bad because they disrupt the gut microbiome, the response generally from a number of people as well, that's only been shown in animal models and indeed that's true.

所以目前来看，我觉得还没有强有力的证据支持哪一方的观点。

So right now, I don't think that there's a strong case one way or the other.

我觉得人们基本上应该问问自己，喜不喜欢人工甜味剂，愿不愿意冒这个风险，这显然是个人的选择。

I think that people should basically ask themselves whether or not they like artificial sweeteners or not, whether or not they're willing to risk it or not, and obviously that's an individual choice.

我还想提一下迭戈·博尔赫斯实验室最近的一项研究，这项研究实际上表明，肠道中的神经元，也就是那些神经足细胞，能够区分真正的糖和人工甜味剂。

I also want to point out a recent study from Diego Borje's lab, which actually shows however, that neurons in the gut, those neuropod cells are actually capable of distinguishing between real sugars and artificial sweeteners.

这是一项非常有趣的研究。

This is a really interesting body of work.

这项研究是最近才发表的，应该说是2022年2月。

It was published just recently, I should say, February 2022.

这篇论文的标题是《对糖而非甜味剂的偏好取决于肠道感觉细胞》。

The title of the paper is The Preference for Sugar Over Sweetener Depends on a Gut Sensor Cell.

简单来说，他们发现有一类神经足细胞能识别肠道中的糖，并通过我们之前讨论过的通路，比如神经节、迷走神经、多巴胺等等，将肠道中有糖的信息传递给大脑。

And to make a long story short, what they showed was there's a category of neuropod cells that recognize sugar in the gut and signal that information about the presence of sugar in the gut to the brain via the pathways we talked about before, the nodos, ganglia, the vagus, dopamine, etcetera, etcetera.

有趣的是，同一类神经元也能对人工甜味剂做出反应，并将信息传递给大脑，但当这些神经元对人工甜味剂和真正的糖做出反应时，传递给大脑的信号模式，以及大脑接收到的特征信号，实际上有很大不同。

Interestingly, the very same category of neurons can respond to artificial sweeteners and signal that information to the brain, but the pattern of signaling and indeed the signature pattern that is conveyed to the brain and received by the brain is actually quite a bit different when these same neurons are responding to artificial sweeteners versus actual sugar.

这非常有趣，因为这意味着，首先，神经元在从肠道向大脑传递信号时具有极高的特异性。

This is very interesting because what it means is, first of all, that neurons have incredible specificity in terms of what they are signaling from the gut to the brain.

这也意味着，大脑可能会收到一种特定的信号，表明摄入的食物或饮料尝起来是甜的，但实际上并没有提供多少营养，也就是说，尽管是甜的，却没有热量。

And it also means that there may be a particular signal that the brain receives that says, I'm receiving some intake of food or drink that tastes sweet, but doesn't actually offer much nutrients in the direction of sweetness, meaning that it doesn't have calories despite being sweet.

再说一次，这些都是潜意识层面的处理。

Now, again, this is all subconscious processing.

和之前讨论的那些关于人工甜味剂和肠道微生物组的研究一样，目前还不清楚这些发现对人类意味着什么。

And like with the previous studies, we were just discussing about artificial sweeteners generally and the gut microbiome generally, it's unclear how this relates to humans at this point in time.

但考虑到小鼠肠道和大脑之间细胞和分子过程的相似性，我认为有理由相信，这些神经足细胞很可能也能在人类体内区分真正的甜味剂和人工甜味剂，尽管这仍有待实证研究。

But given the similarity of cellular processes and molecular processes at the level of gut brain in mice, I think it stands to reason that these neuropod cells very likely are capable of signaling presence of real sweetener versus artificial sweetener in humans as well, although that still remains to be determined empirically.

所以我想简单回顾一下今天讲的内容。

So I'd like to just briefly recap what I've covered today.

我一开始讲了肠脑轴的结构和功能。

I started off by talking about the structure and function of the gut brain axis.

我描述了消化通路的基本结构和功能，以及这个消化通路如何容纳微生物群，也就是很多很多小细菌，它们可以向大脑和身体的其他部分传递各种信号。

I described the basic structure and function of the digestive pathway and how that digestive pathway harbors microbiota species, meaning many, many little bacteria that can signal all sorts of things to the rest of the brain and body.

而且，我们确实讨论了它们传递信号的多种方式。

And indeed, we talked about the various ways that they do that.

我们谈到了直接通路，也就是从肠道延伸到大脑、再从大脑回到肠道的神经网络。

We talked about direct pathways, literally nerve networks that extend from the gut up to the brain and from the brain back to the gut.

我们还讨论了间接途径，比如一些肠道微生物实际上可以合成神经递质，这些神经递质进入血液，影响身体，影响免疫系统，还能进入大脑，在大脑中充当神经递质，就像大脑内部产生的神经递质一样。

And we talked about indirect pathways, how some of the gut microbiota can actually synthesize neurotransmitters that get out into the bloodstream, can impact the body, can impact the immune system and can get into the brain and act as neurotransmitters in the brain, just as would neurotransmitters that originate from within the brain.

我们还讨论了什么样的微生物组是健康的，什么样的不健康。

We also talked about what constitutes a healthy versus unhealthy microbiome.

很明显，拥有多样化的微生物组比不多样化的更健康。

And it's very clear that having a diverse microbiome is healthier than having a non diverse microbiome.

但正如我指出的，关于具体要增强哪些微生物物种、抑制哪些物种，以达到最佳的肠脑轴功能，还有很多问题。

But as I pointed out, there's still a lot of questions as to exactly what microbiota species you want to enhance and which ones you want to suppress in the gut in order to achieve the best gut brain axis function.

我们讨论了禁食之类的事情可能如何影响微生物组，以及其中一些影响可能有点反直觉，考虑到禁食的其他一些积极效果，或者如果我们不只是讨论禁食，还有其他一些限制性饮食，无论是时间限制还是宏量营养素摄入限制，这些可能如何改善或不改善肠道微生物组的健康。

We talked about how things like fasting might impact the microbiome and how some of that might be a little bit counterintuitive based on some of the other positive effects of fasting, or if we're not just discussing fasting, some other types of somewhat restrictive diets, either restrictive in time or restrictive in terms of macronutrient intake, how those may or may not improve the health of gut microbiome.

基本的结论是，因为我们不知道具体饮食如何影响肠道微生物组，也不知道禁食是促进还是损害微生物组，所以我们目前真的无法判断它们是在改善还是损害微生物组。

And the basic takeaway was that because we don't know exactly how specific diets impact the gut microbiome, and we don't know how fasting either promotes or degrades the microbiome, we really can't say whether or not they are improving or degrading the microbiome at this time.

然而，很明显，压力，特别是慢性压力，会破坏肠道微生物组。

However, it is clear that stress, in particular chronic stress, can disrupt the gut microbiome.

当然，也很明显，抗生素会破坏肠道微生物组。

It's also clear of course that antibiotics can disrupt the gut microbiome.

这就把我们带到了益生元和益生菌的话题。

And that brings us to the topic of prebiotics and probiotics.

我强调过，对大多数人来说，摄入高质量、未加工的食物，包括一些益生元纤维，也包括一些益生菌，可能是有益健康的，但益生菌的量不宜过多。

And I emphasize the fact that for most people ingesting high quality non processed foods that include some prebiotic fiber, but also that includes some probiotics will probably be healthy, but not excessive levels of probiotics.

高剂量的补充益生菌，比如益生菌药片或处方益生菌，可能最适合那些处于严重慢性压力下，或者刚结束一轮严重抗生素治疗，或者正在或反复使用抗生素的人。

High levels of supplemented probiotics of the sort that would come in a probiotic pill or even prescription probiotics would probably lend themselves best to when people were under severe chronic stress or had just come off a serious round or an ongoing or repeated rounds of antibiotics.

这并不意味着摄入任何形式或种类的益生菌都不好，只是说高剂量的益生菌，通常以处方或胶囊形式出现，最好保留在特定情况下使用，当然，如果医生开了处方，你应该始终遵循医生的建议，但在某些情况下，比如你有时差反应，因为任何原因过度旅行或过度工作，睡眠不足，或者饮食与平时大相径庭。

That does not mean that ingesting probiotics in any form or any kind is not good, it just means that the very high dose probiotics, again, typically found in prescription form or capsule pill form, probably are best reserved to cases where, of course, your doctor prescribes them, you should always follow your doctor's advice, but in cases where perhaps you are jet lagged, you're traveling excessively for any reason or working excessively, you're not getting enough sleep, or your diet has radically changed from normal.

我们讨论了增加饮食中纤维的量可能有助于增加纤维消化酶和纤维食物的同化，但真正重要的是摄入发酵食品。

And we talked about how increasing the amount of fiber in your diet might be useful for increasing fiber digesting enzymes and the assimilation of fibrous foods, but that it's really the ingestion of fermented foods.

事实上，每天摄入四到六份发酵食品，可以极大地减少体内的炎症标志物，改善整个肠道的微生物多样性，从而改善肠脑轴的信号传导和结果。

And in fact, getting anywhere from four, even up to six servings a day of fermented foods can be immensely beneficial for reducing inflammatory markers in the body and for improving microbiota diversity all along the gut and thereby improving signaling and outcomes along the gut brain axis.

所以我们从结构到功能，再到四种信号传导方式，机械、化学、间接直接，益生菌、纤维和发酵食品，都讲了一遍。

So we went all the way from structure to function to the four kinds of signaling, mechanical, chemical, indirect direct, probiotics, fiber, and fermented foods.

最后我还加了一点关于如何在家自制发酵食品，以尝试抵消一些成本。

And I tossed in a little bit at the end there also about ways that you can make your own fermented foods at home in order to try and offset some of the costs.

而且，做这个也挺好玩的，有些发酵食品味道还真不错。

Also, it's just kind of fun to do, and some of those actually taste quite good.

我发现自己在家做的发酵酸菜，味道其实可以跟超市冷藏区卖的酸菜媲美。

I've actually found that the fermented sauerkraut that we're making at home actually rivals the sauerkraut that you can buy out of the refrigerated section at the grocery store.

我可不是什么熟练的厨师，基本上一点厨艺都没有。

And I am by no means a skilled cook or chef or, and basically have no culinary skill whatsoever.

所以如果我能做到，你也一定能做到。

So if I can do it, you can do it.

希望这些信息对你有用，而且也能实际操作起来。

I hope you found this information useful and perhaps also actionable.

我做这期节目的一个动机，还是为了给和博士的那期节目做个铺垫。

One of my motivations for doing this episode was again, as a primer for the episode with Doctor.

贾斯汀·索南伯格那期，我们会深入探讨肠道微生物组，对肠脑轴讲得少一些，但会非常深入地讲肠道微生物组是什么、它做什么、不做什么，以及他实验室里一些尚未发表的新发现。

Justin Sonnenberg, where we go really deep into the gut microbiome, less so into the gut brain axis, but really deep into the gut microbiome, what it is, what it does, what it doesn't do, and some of the emerging findings from his lab that are yet to be published.

我之所以对做这期节目感到兴奋，也是因为我觉得我们很多人都听说过肠道微生物组。

And I also was excited to do this episode because I think many of us have heard about the gut microbiome.

我们听说肠道里住着一些细菌。

We hear about these bacteria that live in our gut.

我们听说肠脑轴，或者说我们体内90%以上的血清素是在肠道里产生的。

We hear about the gut brain axis or that 90% or more of the serotonin that we make is made in our gut.

我们听说肠道是第二大脑，等等。

We hear about the gut as a second brain and so forth.

但我觉得对很多人来说，他们并不真正清楚肠道微生物组是什么，也不清楚它通过哪些途径和机制向大脑和身体其他部位发送信号。

But I think for many people, they don't really have a clear picture of what the gut microbiome is and the pathways and mechanisms by which it can signal to the brain and to the other parts of the body.

所以我希望今天的信息至少能让大家对这个话题更清楚，让你对我们这个神奇的肠脑轴系统有一个更生动的认识。

So I hope that today's information at least improved the clarity around that topic and leaves you with a more vivid picture of this incredible system that is our gut brain axis.

如果你喜欢这个播客，或者从中有所收获，请订阅我们的YouTube频道。

If you're enjoying and or learning from this podcast, please subscribe to our YouTube channel.

这是支持我们的一种非常好的零成本方式。

That's a terrific zero cost way to support us.

另外，请在Spotify和Apple上订阅播客，在Apple上，你可以给我们留下最高五星的评价。

In addition, please subscribe to the podcast on Spotify and Apple, and on Apple, you can leave us up to a five star review.

在YouTube上，我们有评论区。

On YouTube, we have a comment section.

当然，请给我们反馈和评论，但也请提出你希望我们在Huberman Lab播客中涵盖的话题和嘉宾建议。

Please of course give us feedback and comments, but please also make suggestions about topics and guests that you would like us to include on the Huberman Lab Podcast.

我们确实会看那些评论。

We do read those comments.

另外，请查看今天播客开头提到的赞助商。

In addition, please check out the sponsors mentioned at the beginning of today's podcast.

这可能是支持这个播客最好的方式。

That's perhaps the best way to support this podcast.

如果你还没有在Instagram和Twitter上关注我们，我们的账号是Huberman Lab，在Instagram上。

And if you're not already following us on Instagram and Twitter, it's Huberman Lab on Instagram.

在Twitter上也是Huberman Lab。

It's also Huberman Lab on Twitter.

在那里，我会分享科学和相关的工具，其中一些与播客中涵盖的内容重叠，也有一些是播客中没有的。

And there I cover science and science related tools, some of which overlap with the material covered on the podcast and some of which is distinct from the material covered on the podcast.

也请订阅我们的《神经网络通讯》。

Please also subscribe to our Neural Network Newsletter.

《神经网络通讯》是一份完全免费的通讯，每月发布一次。

The Neural Network Newsletter is a completely zero cost newsletter that comes out once a month.

你可以通过访问hubermanlab.com进行注册。

You can sign up by going to hubermanlab.com.

我们不会把你的邮箱分享给任何人，我们的隐私政策也在那里，非常明确。

We don't share your email with anybody and our privacy policy is there and very clear.

这份通讯包含来自播客的可操作方案和摘要，以及全新的信息。

The newsletter includes actionable protocols and summaries from the podcast, as well as new information entirely.

最后但同样重要的是，感谢你对科学的兴趣。

And last but certainly not least, thank you for your interest in science.