The surprisingly charming science of your gut | Giulia Enders

Summary

The speaker humorously recounts her fascination with the human gut, challenging societal taboos and emphasizing the importance of this complex organ. She delves into the gut's anatomy, its role in digestion, and its surprising connection to our emotions and mental health. The talk explores the gut-brain axis, the impact of bacteria on our well-being, and offers a fresh perspective on cleanliness, advocating for a balanced approach to health.

Takeaways

• 😄 The speaker initially found it easier to say they were going into 'medicine' to appease family members, but faced follow-up questions that led to awkward silences due to their interest in the colon and intestinal tract.
• 🤔 The speaker believes the public generally overlooks the importance of the gut, despite its complexity and role in health, comparing the lack of attention to a magician being ignored for an embarrassing hairstyle.
• 🧠 The gut is incredibly complex, with a large surface area, numerous immune cells, trillions of bacteria, various hormones, and a nervous system that can react even when a part is removed.
• 🤝 The speaker's journey to appreciating the gut began with curiosity about its function, sparked by a roommate's question about how defecation works.
• 🌀 The speaker learned about the inner and outer sphincter muscles and how they work in tandem with the brain to control bowel movements, leading to a newfound respect for these bodily functions.
• 🏠 The realization that the inner sphincter operates independently of external factors and focuses on the individual's needs was comforting and changed the speaker's perspective on using public restrooms.
• 🌿 The speaker began to see the gut's functions, such as rumbling noises and the shape of the stomach, not as embarrassing but as signs of a well-functioning system.
• 🔬 After a personal experience with someone's suicide, the speaker investigated the connection between the gut and the brain, discovering a two-way communication system with significant implications for mental health.
• 🌐 The gut is a major sensory organ, sending 90% of the information to the brain, which influences feelings and emotions, potentially linking gut health with mental well-being.
• 🍵 The speaker suggests that understanding the gut-brain connection can help in managing moods and stresses the importance of considering diet and lifestyle in emotional well-being.
• 🌱 The final step in the speaker's journey was understanding the role of bacteria in the gut, challenging the traditional view of cleanliness and emphasizing the importance of a balanced microbiome for overall health.

Q & A

What was the speaker's initial response to the question 'So, what are you doing?' at family gatherings?

The speaker would simply reply with 'Medicine. I'm going to be a doctor.' This one-word answer would satisfy the curiosity of the family members and make them happy and pleased.

Why did the speaker's enthusiasm for the gut seem to cause awkward silences at family gatherings?

The speaker's enthusiasm for the gut, particularly the colon and intestinal tract, was not a common or comfortable topic of discussion for family members, leading to a decrease in enthusiasm and awkward silences.

What are some of the complexities of the gut that the speaker mentions?

The speaker mentions the large surface area of the gut, the presence of a vast number of immune cells, the activity of 100 trillion bacteria, the production of various hormones, and the complex nervous system of the gut as some of its complexities.

How does the speaker describe the relationship between the gut and the brain?

The speaker describes the gut as a significant advisor to the brain, with 90% of the nervous fibers connecting them carrying information from the gut to the brain, influencing areas related to emotions, self-awareness, and morality.

What is the speaker's perspective on the concept of 'cleanliness' in relation to the gut?

The speaker suggests that real cleanliness is not about eliminating all bacteria but maintaining a healthy balance of good and bad bacteria, which is important for the immune system to function properly.

What was the speaker's roommate's question that sparked her interest in the function of the gut?

The roommate asked, 'Giulia, you study medicine. How does pooping work?' This question led the speaker to research and learn more about the inner workings of the gut.

What is the role of the inner sphincter muscle in the process of defecation?

The inner sphincter muscle is responsible for opening in a reflex to let through a small amount of the leftover digestion for testing by sensory cells. These cells then send information to the brain to determine if it's time to go to the toilet.

How does the speaker's understanding of the gut influence her approach to mood and mental health?

The speaker considers the gut's influence on mood and mental health, suggesting that by understanding the gut-brain connection, one can be more aware of how internal factors, such as diet and stress, may affect mental well-being.

What is the 'hygiene hypothesis' mentioned by the speaker?

The hygiene hypothesis suggests that having too few microbes in one's environment due to excessive cleaning can lead to an increase in allergies or autoimmune diseases.

How does the speaker's view on the gut change her perspective on life and cleanliness?

The speaker's understanding of the gut's complexity and importance leads her to value the balance of good and bad bacteria, which she applies to her view on life, suggesting that fostering the good while acknowledging the presence of the bad can have a calming effect.

Outlines

00:00

😄 Embracing the Fascination with the Colon

The speaker humorously recounts their experience with family gatherings where they would answer the question 'So, what are you doing?' with the word 'Medicine.' This would initially satisfy their relatives, but when asked about their specialty, they would admit to being fascinated with the colon. The speaker notes the complexity and importance of the gut, which is often overlooked despite its significant role in our health. They believe that the gut is charming and deserves more attention. The speaker then invites the audience to follow them on a journey of understanding the gut through three steps: observing its function, questioning its design, and appreciating its complexity.

05:02

🤔 The Inner Sphincter and the Gut's Role in Health

The speaker delves into the anatomy and function of the gut, focusing on the inner and outer sphincters and how they work together to control bowel movements. They describe the process of digestion and how the body decides when to expel waste, highlighting the role of sensory cells and the brain in this process. The speaker also discusses the importance of the gut in overall health, touching on its connection to the brain and its influence on mood and mental health. They mention the gut's role as a sensory organ and its impact on areas of the brain related to emotions and self-awareness, suggesting that gut health can have significant effects on mental well-being.

10:04

🌐 The Gut-Brain Connection and the Importance of Bacteria

The speaker explores the connection between the gut and the brain, emphasizing that the gut is not just a passive recipient of commands from the brain but an active participant in communication. They discuss the role of the gut in providing the brain with information about the body's internal state, which can influence feelings and emotions. The speaker also addresses the relationship between gut health and mental health disorders like anxiety and depression. Furthermore, they touch on the concept of 'real cleanliness,' which involves maintaining a healthy balance of good and bad bacteria in the gut. The speaker concludes by reflecting on how understanding the gut's role in health and the importance of bacteria can lead to a more balanced and accepting perspective on cleanliness and health.

Keywords

💡Medicine

Medicine is the field of study and practice that focuses on the diagnosis, treatment, and prevention of diseases. In the script, the speaker initially uses the term 'medicine' as a simple answer to the question 'So, what are you doing?' to satisfy the curiosity of family members. However, it is later revealed that the speaker's true interest lies in a more specific area of medicine, which is the study of the gastrointestinal tract.

💡Colon

The colon is the large intestine, a part of the digestive system that plays a crucial role in processing waste and absorbing water. The speaker mentions being 'fascinated with the colon,' indicating a deeper interest in the gastrointestinal system. This fascination extends from the anus to the entire intestinal tract, highlighting the speaker's unique focus within the field of medicine.

💡Intestinal Tract

The intestinal tract refers to the entire length of the digestive system, from the mouth to the anus. The speaker's interest in the 'whole intestinal tract' rather than a specific organ or system shows a holistic approach to understanding the digestive process. This interest is a central theme in the video, as it leads to a deeper exploration of the functions and importance of this part of the body.

💡Immune Cells

Immune cells are a type of white blood cell that plays a vital role in defending the body against infections and other diseases. The script mentions that there are many immune cells being 'trained' in the tight pipe of the gut, emphasizing the gut's role in the immune system. This connection between the gut and the immune system is a key point in the video, illustrating the complexity and importance of the gastrointestinal tract.

💡Bacteria

Bacteria are microscopic, single-celled organisms that can exist in various environments, including the human body. The speaker talks about '100 trillion bacteria' in the gut, which are involved in various processes such as digestion and immune function. This concept is crucial in the video as it challenges the traditional view of cleanliness and introduces the idea of a healthy microbial balance in the gut.

💡Hormones

Hormones are chemical messengers that regulate various physiological processes in the body. The script mentions about 20 different hormones being produced in the gut, indicating the gut's role in endocrine regulation. This highlights the multifunctional nature of the gut, which goes beyond digestion to include hormone production and regulation.

💡Nervous System

The nervous system is a complex network of nerves and cells that transmit signals between different parts of the body. The speaker describes the gut's nervous system as being 'so complex' that it can 'mumble back' when stimulated, suggesting a level of autonomy and interaction with the brain. This concept is central to the video's theme of the gut's importance and its connection to the brain.

💡Inner Sphincter

The inner sphincter is a muscle that controls the passage of waste from the rectum to the anus. The speaker discusses the inner sphincter's role in the process of defecation, highlighting its reflexive action and its interaction with sensory cells. This concept is used in the video to illustrate the intricate mechanisms of the digestive system and the body's ability to regulate waste elimination.

💡Gut-Brain Connection

The gut-brain connection refers to the bidirectional communication between the gastrointestinal tract and the central nervous system. The script explores this connection, emphasizing that 90% of the nervous fibers connecting the gut and brain carry information from the gut to the brain. This concept is pivotal in the video, as it challenges the traditional view of the brain as the sole decision-maker and highlights the gut's role in influencing mood and overall well-being.

💡Cleanliness

Cleanliness in the context of the video is not just about physical hygiene but also about maintaining a healthy balance of bacteria in the gut. The speaker discusses the concept of 'real cleanliness' and how it involves having both good and bad bacteria in the gut. This idea is central to the video's message about the importance of a balanced microbial environment for overall health.

💡Irritable Bowel Syndrome (IBS)

Irritable Bowel Syndrome is a common disorder that affects the large intestine and can cause symptoms like cramping, abdominal pain, bloating, gas, diarrhea, and constipation. The script mentions that people with IBS or inflammatory bowel disease have a higher risk of anxiety or depression, linking gut health to mental health. This connection is a key point in the video, illustrating the interplay between physical and mental well-being.

Highlights

The speaker initially used the word 'Medicine' as a simple answer to avoid detailed questions about their career aspirations in the field of gastroenterology.

The speaker believes that the public lacks interest in the anatomy and functions of the gastrointestinal tract despite its importance.

The speaker humorously compares the lack of attention to the gut to not checking out a magician due to an embarrassing hairstyle.

Science has historically disliked the gut due to its complexity, large surface area, high concentration of immune cells, and the presence of trillions of bacteria.

The gut is more complex than the genitals, with 20 different hormones and a highly developed nervous system.

The speaker's roommate unknowingly sparked their interest in the inner workings of the gastrointestinal system.

There are two sphincter muscles involved in the process of defecation, with the inner sphincter being less understood and more fascinating.

The inner sphincter muscle operates on a reflex, testing the contents before signaling the brain for a potential need to use the toilet.

The speaker learned to appreciate the complexity and functionality of the body's systems, including the inner sphincter.

The speaker suggests that societal norms and expectations can influence bowel movements and the body's response to different environments.

The speaker discovered a connection between the gut and the brain, with the gut potentially influencing mental health.

90% of the nervous fibers connecting the gut and brain carry information from the gut to the brain, indicating a strong two-way communication.

Conditions like irritable bowel syndrome may be linked to mental health issues, suggesting a deeper connection between physical and mental well-being.

The speaker encourages a reevaluation of what cleanliness means, suggesting that a balance of good and bad bacteria is healthier than sterility.

The concept of 'life hygiene' is introduced, emphasizing the importance of fostering good while acknowledging the presence of bad.

The speaker concludes by expressing hope that their talk has provided valuable insights and a new perspective on the importance of the gut.

Transcripts

A few years ago,

I always had this thing happening to me,

especially at family gatherings

like teas with aunts and uncles or something like this.

When people come up to you,

and they ask you, "So, what are you doing?"

And I would have this magical one-word reply,

which would make everybody happy:

"Medicine.

I'm going to be a doctor."

Very easy, that's it, everybody's happy and pleased.

And it could be so easy,

but this effect really only lasts for 30 seconds with me,

because that's then the time when one of them would ask,

"So, in what area of medicine?

What specialty do you want to go into?"

And then I would have to strip down in all honesty and just say,

"OK, so I'm fascinated with the colon.

It all started with the anus,

and now it's basically the whole intestinal tract."

(Laughter)

And this would be the moment when the enthusiasm trickled,

and it would maybe also get, like, awkwardly silent in the room,

and I would think this was terribly sad,

because I do believe our bowels are quite charming.

(Laughter)

And while we're in a time where many people are thinking about

what new superfood smoothie to make

or if gluten is maybe bad for them,

actually, hardly anyone seems to care about the organ where this happens,

the concrete anatomy and the mechanisms behind it.

And sometimes it seems to me

like we're all trying to figure out this magic trick,

but nobody's checking out the magician,

just because he has, like,

an embarrassing hairstyle or something.

And actually,

there are reasons science disliked the gut for a long time;

I have to say this.

So, it's complex.

There's a lot of surface area --

about 40 times the area of our skin.

Then, in such a tight pipe,

there are so many immune cells that are being trained there.

We have 100 trillion bacteria doing all sorts of things --

producing little molecules.

Then there's about 20 different hormones,

so we are on a very different level than our genitals, for example.

And the nervous system of our gut is so complex

that when we cut out a piece,

it's independent enough that when we poke it,

it mumbles back at us, friendly.

(Laughter)

But at least those reasons are also the reasons why it's so fascinating

and important.

It took me three steps to love the gut.

So today, I invite you to follow me on those three steps.

The very first was just looking at it

and asking questions like, "How does it work?"

and "Why does it have to look so weird for that sometimes?"

And it actually wasn't me asking the first kind of these questions,

but my roommate.

After one heavy night of partying,

he came into our shared-room kitchen,

and he said, "Giulia, you study medicine. How does pooping work?"

(Laughter)

And I did study medicine but I had no idea,

so I had to go up to my room and look it up in different books.

And I found something interesting, I thought, at that time.

So it turns out, we don't only have this outer sphincter,

we also have an inner sphincter muscle.

The outer sphincter we all know, we can control it,

we know what's going on there;

the inner one, we really don't.

So what happens is,

when there are leftovers from digestion,

they're being delivered to the inner one first.

This inner one will open in a reflex

and let through a little bit for testing.

(Laughter)

So, there are sensory cells

that will analyze what has been delivered: Is it gaseous or is it solid?

And they will then send this information up to our brain,

and this is the moment when our brain knows,

"Oh, I have to go to the toilet."

(Laughter)

The brain will then do what it's designed to do

with its amazing consciousness.

It will mediate with our surroundings,

and it will say something like,

"So, I checked.

We are at this TEDx conference -- "

(Laughter)

(Applause)

Gaseous?

Maybe, if you're sitting on the sides,

and you know you can pull it off silently.

(Laughter)

But solid --

maybe later.

(Laughter)

Since our outer sphincter and the brain is connected with nervous cells,

they coordinate, cooperate,

and they put it back in a waiting line --

(Laughter)

for other times,

like, for example, when we're at home sitting on the couch,

we have nothing better to do,

we are free to go.

(Laughter)

Us humans are actually one of the very few animals that do this

in such an advanced and clean way.

To be honest, I had some newfound respect

for that nice, inner sphincter dude --

not connected to nerves

that care too much about the outer world or the time --

just caring about me for once.

I thought that was nice.

And I used to not be a great fan of public restrooms,

but now I can go anywhere,

because I consider it more

when that inner muscle puts a suggestion on my daily agenda.

(Laughter)

And also I learned something else, which was:

looking closely at something I might have shied away from --

maybe the weirdest part of myself --

left me feeling more fearless,

and also appreciating myself more.

And I think this happens a lot of times

when you look at the gut, actually.

Like those funny rumbling noises that happen

when you're in a group of friends

or at the office conference table,

going, like, "Merrr, merrr..."

This is not because we're hungry.

This is because our small intestine is actually a huge neat freak,

and it takes the time in between digestion to clean everything up,

resulting in those eight meters of gut -- really, seven of them --

being very clean and hardly smelling like anything.

It will, to achieve this, create a strong muscular wave

that moves everything forward that's been leftover after digestion.

This can sometimes create a sound,

but doesn't necessarily have to always.

So what we're embarrassed of is really a sign

of something keeping our insides fine and tidy.

Or this weird, crooked shape of our stomach --

a bit Quasimodo-ish.

This actually makes us be able to put pressure on our belly

without vomiting,

like when we're laughing

and when we're doing sports,

because the pressure will go up and not so much sideways.

This also creates this air bubble

that's usually always very visible in X-rays, for example,

and can sometimes, with some people,

when it gets too big,

create discomfort or even some sensations of pain.

But for most of the people, is just results

that it's far easier to burp when you're laying on your left side

instead of your right.

And soon I moved a bit further

and started to look at the whole picture of our body and health.

This was actually after I had heard

that someone I knew a little bit had killed himself.

It happened that I had been sitting next to that person the day before,

and I smelled that he had very bad breath.

And when I learned of the suicide the next day,

I thought: Could the gut have something to do with it?

And I frantically started searching if there were scientific papers

on the connection of gut and brain.

And to my surprise, I found many.

It turns out it's maybe not as simple as we sometimes think.

We tend to think our brain makes these commands

and then sends them down to the other organs,

and they all have to listen.

But really, it's more that 10 percent of the nerves that connect brain and gut

deliver information from the brain to the gut.

We know this, for example, in stressful situations,

when there are transmitters from the brain that are being sensed by our gut,

so the gut will try to lower all the work,

and not be working and taking away blood and energy

to save energy for problem-solving.

This can go as far as nervous vomiting or nervous diarrhea

to get rid of food that it then doesn't want to digest.

Maybe more interestingly,

90 percent of the nervous fibers that connect gut and brain

deliver information from our gut to our brain.

And when you think about it a little bit,

it does make sense, because our brain is very isolated.

It's in this bony skull surrounded by a thick skin,

and it needs information to put together a feeling

of "How am I, as a whole body, doing?"

And the gut, actually, is possibly the most important advisor for the brain

because it's our largest sensory organ,

collecting information not only on the quality of our nutrients,

but really also on how are so many of our immune cells doing,

or things like the hormones in our blood that it can sense.

And it can package this information, and send it up to the brain.

It can, there, not reach areas like visual cortex or word formations --

otherwise, when we digest,

we would see funny colors or we would make funny noises -- no.

But it can reach areas for things like morality,

fear or emotional processing

or areas for self-awareness.

So it does make sense

that when our body and our brain are putting together this feeling

of, "How am I, as a whole body, doing?"

that the gut has something to contribute to this process.

And it also makes sense

that people who have conditions like irritable bowel syndrome

or inflammatory bowel disease

have a higher risk of having anxiety or depression.

I think this is good information to share,

because many people will think,

"I have this gut thing, and maybe I also have this mental health thing."

And maybe -- because science is not clear on that right now --

it's really just that the brain is feeling sympathy with their gut.

This has yet to grow in evidence until it can come to practice.

But just knowing about these kinds of research

that's out there at the moment

helps me in my daily life.

And it makes me think differently of my moods

and not externalize so much all the time.

I feel oftentimes during the day we are a brain and a screen,

and we will tend to look for answers right there

and maybe the work is stupid or our neighbor --

but really, moods can also come from within.

And just knowing this helped me,

for example, when I sometimes wake up too early,

and I start to worry and wander around with my thoughts.

Then I think, "Stop. What did I eat yesterday?

Did I stress myself out too much?

Did I eat too late or something?"

And then maybe get up and make myself a tea,

something light to digest.

And as simple as that sounds,

I think it's been surprisingly good for me.

Step three took me further away from our body,

and to really understanding bacteria differently.

The research we have today is creating a new definition

of what real cleanliness is.

And it's not the hygiene hypothesis --

I think many maybe know this.

So it states that when you have too little microbes in your environment

because you clean all the time,

that's not really a good thing,

because people get more allergies or autoimmune diseases then.

So I knew this hypothesis,

and I thought I wouldn't learn so much

from looking at cleanliness in the gut.

But I was wrong.

It turns out,

real cleanliness is not about killing off bacteria right away.

Real cleanliness is a bit different.

When we look at the facts,

95 percent of all bacteria on this planet don't harm us -- they can't,

they don't have the genes to do so.

Many, actually, help us a lot,

and scientists at the moment are looking into things like:

Do some bacteria help us clean the gut?

Do they help us digest?

Do they make us put on weight or have a lean figure

although we're eating lots?

Are others making us feel more courageous or even more resilient to stress?

So you see, there are more questions when it comes to cleanliness.

And, actually, the thing is, it's about a healthy balance, I think.

You can't avoid the bad all the time.

This is simply not possible;

there's always something bad around.

So what really the whole deal is when you look at a clean gut,

it's about having good bacteria, enough of them,

and then some bad.

Our immune system needs the bad, too,

so it knows what it's looking out for.

So I started having this different perspective on cleanliness

and a few weeks later,

I held a talk at my university,

and I made a mistake by 1,000.

And I went home and I realized in that moment,

I was like, "Ah! I made a mistake by 1,000.

Oh God, that's so much, and that's so embarrassing."

And I started to think about this, I was like, "Ugh!"

And after a while I said,

"OK, I made this one mistake,

but then I also told so many good and right and helpful things,

so I think it's OK, you know?

It's a clean thing."

And then I was like, "Oh, wait.

Maybe I took my perspective on cleanliness further."

And it's my theory at the moment that maybe we all do.

Take it a bit further than just cleaning our living room,

where maybe we make it to sort like a life hygiene.

Knowing that this is about fostering the good

just as much as trying to shelter yourself from the bad

had a very calming effect on me.

So in that sense,

I hope today I told you mostly good and helpful things,

and thank you for your time,

for listening to me.

(Applause)