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The ONE Disease That Smoking Can Help Treat - Video học tiếng Anh
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The ONE Disease That Smoking Can Help Treat
The ONE Disease That Smoking Can Help Treat
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0:00
So some people might already know this, but I have ulcerative colitis.
0:03
After the whole cancer thing, it’s gotten actually quite a bit better.
0:07
But treating it has been pretty difficult over the course of my life.
0:11
Hasn’t been fun the whole time, I’ll tell you what.
0:13
There was a couple of years there I could not fart safely.
0:16
Ulcerative colitis is one of a few kinds of inflammatory bowel diseases,
0:21
and those diseases can be very bad for anyone that has them.
0:25
There’s no cure, and the treatments aren’t always effective for everybody.
0:29
But new research suggests that a promising treatment for certain types of
0:33
chronic inflammatory bowel disease might come from something that
0:36
we know is absolutely terrible for you in every other way: smoking.
0:41
[♪ INTRO]
0:45
Let’s start with a quick note on what we’re talking about here.
0:48
Crohn’s disease and ulcerative colitis are both forms of
0:51
inflammatory bowel disease, AKA IBD.
0:54
The classic characteristic of both these diseases is that,
0:57
like the name suggests, they cause inflammation and damage in your gut.
1:01
This is different from IBS or irritable bowel syndrome,
1:04
which definitely causes pain and discomfort,
1:06
but doesn’t cause physical damage to your GI.
1:09
No inflammation, hence, not IBD.
1:12
It’s annoying that IBD starts with I, but it’s a different I.
1:16
Inflammation or irritable.
1:17
So for this video, I’m talking about IBD.
1:19
I’m not talking about IBS.
1:21
There are also a few conditions that don’t exactly look like Crohn’s
1:24
or ulcerative colitis, so those can land in the
1:27
super helpful “IBD unclassified” category.
1:30
But most of the time IBD is referring to ulcerative colitis or Crohn’s disease.
1:34
Symptoms of both Crohn’s and UC can include nausea, gut pain, weight loss,
1:39
fatigue, and some, shall we say, unpleasant bathroom experiences.
1:43
Those symptoms can cool off or flare up depending on medications you’re taking,
1:48
what food you’ve eaten recently,
1:49
your level of stress or just complete and total randomness.
1:53
And IBD of any type can cause problems outside of your gut too.
1:56
All that inflammation in your gut can make it harder
1:58
for your body to absorb enough nutrients.
2:01
Some research estimates that up to 85%
2:03
of people with IBD suffer from malnutrition.
2:06
In adults, that can cause weight loss, but for children,
2:08
it can even stunt their growth.
2:10
And as your body struggles to absorb things like protein, vitamins, or electrolytes,
2:14
it can affect your whole body, including your muscles, bones, skin, hair, and eyes.
2:19
In particular, these conditions make it harder to absorb iron,
2:22
and that combined with the literal wounds in your gut can lead to anemia.
2:27
While your guts might be draining like a faucet,
2:30
your blood and energy reserves are too, causing fatigue.
2:33
So not only are you feeling crappy, you’re just generally pooped too.
2:37
So, why does this happen?
2:40
Well, it’s all thanks to your immune system
2:41
going rogue and not doing what it’s supposed to do.
2:44
They’re all autoimmune disorders, where your immune system
2:47
gets its wires crossed and starts attacking your gut tissue.
2:50
Researchers are still trying to identify an exact cause,
2:53
and right now it seems like there are multiple things
2:56
that can contribute to someone’s risk of developing IBD.
2:59
Genetics is a big one, and researchers are investigating whether
3:02
mutations related to reigning in your immune system,
3:04
managing your gut bacteria, and determining the thickness
3:07
of your gut’s mucus barrier might play a role.
3:10
Then the environmental factors, like antibiotics, processed foods, or stress,
3:14
might step in to piss off your immune system and trigger the disease
3:18
if you have the genetics to predispose you to that kind of thing.
3:21
But even with all this overlap between Crohn’s disease and ulcerative colitis,
3:25
they are distinct diseases, and the main difference is
3:28
where the problem shows up in the gut.
3:30
Ulcerative colitis strikes the rectum and colon,
3:33
while Crohn’s can target anywhere in the GI tract,
3:36
though it seems to prefer the end of the small intestine
3:39
and the beginning of the large intestine.
3:41
There’s also a difference when it comes to exactly
3:43
how the immune system freaks out.
3:45
In Crohn’s disease, immune cells called T helper cells type 1, or TH1s,
3:50
seem to be the main culprit.
3:51
And in ulcerative colitis, it’s the atypical T helper cells type 2,
3:55
or TH2s, that cause the most trouble.
3:58
Both types of cells produce cytokines, which are signaling molecules.
4:02
Think of them as your immune systems version of a flare gun.
4:05
All of those cytokines trigger the inflammatory response and activate
4:08
other immune cells, calling the immune system
4:10
to battle against the gut tissue itself.
4:13
So all of this is pretty bad, which is why there’s been so much work
4:17
investigating how to treat these diseases.
4:19
And at least when it comes to UC, it seems like a potential treatment might
4:23
also be the one thing that we all know is terrible for our health: smoking.
4:29
You’ve heard this everywhere: smoking is bad for you.
4:32
Your lungs hate smoking. Your heart and blood vessels hate smoking.
4:35
Your brain hates smoking.
4:36
Heck, even your eyes, reproductive system, and pancreas hate smoking.
4:40
Smoking is associated with everything from strokes to diabetes,
4:44
heart attacks, and an absolute smorgasbord of cancers.
4:47
But researchers have noticed a weird connection between smoking and UC,
4:52
but this time, it’s a good thing.. As in, their ulcerative colitis
4:56
gets better if they smoke.
4:58
People first started noticing correlation back in the ‘80s.
5:02
Some researchers realized that only a very small fraction
5:04
of the ulcerative colitis patients at their clinic were smokers.
5:08
And whether you were alive back then or have ever seen
5:10
an episode of Stranger Things, that might make you raise an eyebrow,
5:13
because smoking was super popular in the ‘80s.
5:16
Having a small number of smokers in any group of people was pretty unusual.
5:20
In their study, 44% of people smoked in the control group,
5:24
but only 8% of ulcerative colitis patients were smokers.
5:27
According to survey data, smoking rates through the ‘80s in the UK
5:31
ranged from about 30 to 35%, so these ulcerative colitis patients
5:35
were weird even among the general public.
5:37
They also found that non-smokers were anywhere from three to six times
5:41
more likely to develop ulcerative colitis than smokers were.
5:45
With numbers like that, you don’t need a gut feeling
5:48
to know something weird was going on.
5:50
So, researchers knew that smoking had a protective effect against ulcerative colitis.
5:54
What was less clear was why.
5:56
In the 1990s, scientists had done a handful of clinical trials where
6:00
they tried to treat ulcerative colitis with nicotine gum, patches, or even enemas.
6:06
At the time, they hypothesized that that nicotine might make mucus
6:09
in the colon thicker, helping to protect the tissue,
6:12
or that it might help suppress immune response.
6:14
But those explanations don’t exactly fit,
6:17
because those kinds of changes would be expected to improve
6:20
any autoimmune disease affecting the gut.
6:22
And as it turns out, not all forms of IBD like it when you light up.
6:26
In fact, while smoking decreases your risk of getting ulcerative colitis,
6:30
it increases your overall risk of getting Crohn’s disease.
6:33
And while treating Crohn’s disease isn’t always easy,
6:35
quitting smoking is one of the few things you can do to improve your symptoms.
6:40
Remember those environmental factors that can increase risk of developing IBD?
6:43
Smoking is one of them, at least when it comes to Crohn’s.
6:47
Plus, people who continued smoking after they got diagnosed with Crohn’s disease
6:51
were more likely to have a poorer outcome and more frequent flare-ups.
6:56
Smoking might also increase the need for hospital stays and surgical intervention.
7:00
All in all, smoking seems to be very bad for people with Crohn’s disease.
7:04
Which also means that a lot of those ideas from the ‘90s about nicotine
7:08
doing stuff to your gut don’t make sense, because if it was that simple,
7:12
then Crohn’s patients would see just as many
7:14
benefits as ulcerative colitis patients do.
7:16
So researchers knew something else had to be going on in order for
7:20
smoking to be so good for one IBD and so bad for the other.
7:24
And good news! They think they’ve cracked it. It’s all about your gut bacteria.
7:29
Now, there’s evidence that nicotine specifically can help to suppress those TH2
7:34
cells that are so overactive in ulcerative colitis, but that’s not the whole story.
7:38
A study from the RIKEN Center for Integrative Medical Sciences
7:42
found that a better answer might already be on the tip of your tongue.
7:46
Everybody’s got a whole community of bacteria living in our mouths.
7:49
Yes, even if you’re really good about brushing your teeth.
7:52
Most of them don’t cause any trouble, and a few are even good for you.
7:55
One of those common mouth bacteria are Streptococcus species.
7:58
Don’t worry, these aren’t the kind that give you strep throat or cause
8:02
flesh eating diseases or anything like that.
8:03
They’re the good guys!
8:04
And when you swallow, bacteria in your mouth can travel down your GI
8:08
with your saliva, including those Strep bacteria.
8:11
Usually, they just get a free ride all the way through it to your toilet.
8:15
The weird thing was that in people with ulcerative colitis who smoke,
8:19
researchers found a buttload of these Streptococcus bacteria in their colons.
8:24
Something about smoking was letting this oral bacteria
8:27
stick around in the colon, rather than just pass through.
8:30
The researchers swabbed smokers' mouths for that oral bacteria,
8:34
isolated several species, and then put them into the guts of mice
8:37
with either Crohn’s or ulcerative colitis.
8:40
They found that it was specifically Streptococcus mitis
8:43
that mimicked the effects of smoking.
8:45
Giving it to the ulcerative colitis mice caused their inflammation to go down.
8:49
But in the Crohn’s disease mice, it led to inflammation up the wazoo.
8:53
Even though this bacteria is usually harmless in healthy people,
8:56
it has a direct effect on IBD symptoms.
8:59
And since IBDs are the immune system going out of whack,
9:02
the next step was for the researchers to see
9:05
how this bacteria can influence the immune system at large.
9:08
They found that Strep mitis triggers an increase in TH1 cells in the gut,
9:13
which means for Crohn’s disease, it takes a crappy situation and makes it crappier.
9:17
But in ulcerative colitis, since the major cell responsible is TH2,
9:22
bonus TH1 is no problem.
9:24
It turns out the increase in TH1 cells can actually help combat the TH2 cells,
9:29
which is what reduces the colitis inflammation.
9:32
All of that explains how Strep mitis can exacerbate or improve IBD
9:37
depending on the condition, but it still doesn’t explain
9:40
why smoking makes those bacteria stick around in the gut.
9:43
So to answer that, the researchers had to circle back to
9:46
what smoking leaves behind.
9:48
When you smoke a cigarette, the burning of the tobacco produces benzene,
9:52
which is a carcinogenic chemical.
9:54
That gets into your lungs through the smoke that you are inhaling,
9:57
and then your body then breaks that down into a bunch of other stuff,
10:00
including a metabolite called hydroquinone.
10:02
That metabolite was, unsurprisingly,
10:04
found at much higher concentrations in the guts of smokers than non-smokers.
10:09
Previous research has found that hydroquinone can have
10:12
immunosuppressive effects, which could help dampen
10:15
ulcerative colitis all on its own.
10:17
And it’s that immunosuppression that makes the gut less equipped to stop
10:21
your mouth bacteria from setting up shop in your colon.
10:24
In fact, hydroquinone seems to promote the growth of Strep mitis in the intestines.
10:30
So smoking leads to more hydroquinone, which allows for Strep mitis
10:34
from the mouth to grow in the intestines, which then increases the presence of
10:37
TH1 cells, reducing TH2 cells and the ulcerative colitis inflammation
10:42
that comes with them. Simple!
10:44
Now to be clear, this was a relatively small study,
10:46
but it does explain why smoking both eases ulcerative colitis symptoms
10:50
and makes the symptoms of Crohn’s disease worse.
10:53
And I know what you’re thinking.
10:54
Anyone with ulcerative colitis, should they just like pick up smoking?
10:58
Well, no. Smoking is still very bad for the rest of your body,
11:01
and ulcerative colitis won’t stop you from getting lung cancer from those cigarettes.
11:06
Instead, the researchers propose that future treatment options
11:09
might be planting this bacteria into the colons of people with ulcerative colitis,
11:14
or even just giving them hydroquinone directly.
11:17
And they’ve actually tried that second option, at least in animal models.
11:21
A study from 2014 gave mice with ulcerative colitis an oral form
11:25
of hydroquinone called zonarol to see how it affected their symptoms.
11:29
And the findings were pretty significant.
11:31
Mice in this treatment group had fewer pro-inflammatory molecules,
11:35
smaller ulcers, fewer disease symptoms like bloody stools,
11:38
and fewer immune cells attacking in general.
11:41
But that’s just how it worked in mice.
11:43
Right now, the only hydroquinone on the market for humans is designed
11:47
to treat hyperpigmentation, and it’s only FDA approved to go on the skin.
11:52
There is no safe oral option for people,
11:54
and there’s also some evidence that hydroquinone could be harmful to the liver,
11:58
so unless a doctor tells you otherwise,
12:00
hydroquinone in any form shouldn’t be considered a viable treatment for UC.
12:04
Figuring out how to get hydroquinone safely to the gut without damaging
12:08
the liver would be part of the battle,
12:10
and that’s if we can even confirm that it works as well in us as it does in mice.
12:14
It often doesn’t and also it often does more damage to our bodies
12:17
than it does to the bodies of mice.
12:19
There’s reasons we do this research.
12:20
For the average person, trying to get Strep mitis into your colon also isn’t an option.
12:25
Permanently changing the gut microbiome isn’t as easy as swallowing
12:28
a pill or even doing a fecal transplant, since you’d need the bacteria
12:32
to survive this sudden relocation in order to reap the benefits.
12:36
Plus, there could always be unforeseen consequences when you
12:39
mess with the gut microbiome, since it can affect everything from
12:42
weight and allergies to your brain and risk of cancer.
12:46
But this research at least explains why smoking benefits colons
12:49
with ulcerative colitis, and why it very much doesn’t
12:51
benefit intestines afflicted with Crohn’s.
12:53
And for diseases with no known cure, that’s at least a step in the right direction.
12:58
But remember, no matter what your colon thinks, smoking is still bad!
13:03
[♪ OUTRO]
