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January 18, 2024 17 mins
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Speaker 1 (00:01):
Welcome to brain Stuff, a production of iHeartRadio. Hey, brain Stuff,
I'm Lauren Vogelbaum, and this is a special episode because
a while back, iHeartRadio and the Metaverse invited me to
come to a video that was released exclusively on Roadblocks
and Fortnite, and in it they let me go on
pretty much as much as I wanted about bacteria. It

(00:24):
was a dream I never knew I had, so that
was a thing that I did. But now we wanted
to bring that script and all of the weird stuff
in it to you, because, Okay, bacteria are tiny organisms
that only consist of a single cell, without so much
as a cell nucleus to direct them. Yet they do

(00:44):
incredible things. They're all around us and inside us doing
cool stuff of their own accord. But we humans have
also harnessed them to do all kinds of work for us.
We've talked here before about the dirt bacteria response for petrocore,
which is the smell after a rain, and the gut

(01:04):
bacteria that lets squirrels build muscle even while they hibernate,
and the cyanobacteria that turned Earth's ancient ocean's pink for
eons before green algae hit the scene. Also over on
another podcast I do called Sabor, we talk all the
time about how the byproducts of bacteria that are just
living their lives help produce some of our favorite foods

(01:25):
and flavors, from tangy cheeses to crunchy pickles to rich
chocolate and coffee. And that's just stuff that we've already covered. Today,
we're going to go on a tour of the bacterial microverse.
Let's start our tour on a perhaps uncomfortably personal level,
of the bacteria in your guts. Okay, the community of

(01:50):
microorganisms that lives on and inside you is known as
the human microbiome. It's perhaps surprisingly large. Back in twenty sixteen,
scientists estimated that on average, you probably have slightly more
bacterial cells in your body than you have cells of
your own. A healthy microbiome helps your skin stay clear,

(02:12):
your guts, digest food, your immune system, learn how to fight.
Healthy gut microbes even seem to help reduce people's anxiety
and improve their mood. And research suggests that our microbiomes
have their own circadium rhythms just like we do, and
that these daily rhythms have a lot of impact on
our hell circadium rhythms are in organisms patterns of activity

(02:34):
and arrest throughout any given day and night. Okay, a
few years back, there was a study done in mice
using cutting edge DNA sequencing technology. The research team found
that the microbial communities living in the guts of mice
have a pretty regular routine. Different types of bacteria hang
out in their own areas of the intestines in the morning,

(02:56):
move around during the day, and end up in a
different place at then do it all over again. So
each part of a mouse's gut experiences differences in numbers
and species of bacteria over a twenty four hour period.
And that's not all. And this migration affected organs in
the mice that weren't even close to the gut. For example,

(03:20):
the daily rhythms of those gut bacteria, depending on the
time of day, changed the liver's ability to do its
job producing useful stuff and getting rid of waste. This
isn't just super weird, which it is, It could eventually
help doctors understand how the time of day and the
health of your microbiome may make a difference in treating

(03:41):
some diseases. Also, the researchers found that the mouse's own
circadian rhythms were essentially driven by those of its microbiome.
There was no separating the two. They said that we
should all think of ourself and our microbiome as a
single supra organism. But as much as we're still learning

(04:02):
about the bacteria that are most personal to us, humans
have figured out a lot of ways to put other
bacteria to work. Even though most are too small to
be seen without a microscope, their strength is in their numbers.
If you can convince bacteria to produce a certain substance,
and you can get them to thrive, a colony of
bacteria will produce that substance for you. On an industrial scale.

(04:27):
Everything from flavorings used in the food industry to human
insulin is made this way. Take butter flavoring. Originally, butter
was butter flavored because of helpful bacteria cultures that aid
in transforming liquid milk into this solid fat, which is butter.
As those bacteria worked, they also happened to excrete compounds

(04:49):
that we humans experience as flavors. Butter flavor is bacteria poop. However,
a lot of butter sold these days, certainly in the
United States, is what's called sweet cream butter which has
not gone through a bacterial culturing process and thus doesn't
taste particularly buttery. Some of this is just sold as is,

(05:11):
but some of it has butter flavor added in, and
in order to make that butter flavoring, sometimes scientists create
it in a lab that's called artificial flavoring. But sometimes
they turn back to bacteria and use bacterial colonies to
produce the flavor molecules that can be labeled natural flavoring.
And of course we apply both of these types, natural

(05:33):
and artificial to all kinds of baked goods, candies, and
popcorn seasonings. But we bend bacteria to for experimental uses too.
For example, take the team up of glowing bacteria and
lasers to detect and then disarm land mines. There may
be more than one hundred million land mines lurking underground

(05:55):
in former conflict zones around the world, and for a
long time, the best way to remove them was by
sending a volunteer into a mine field with a metal detector.
Not ideal. That's why a team of researchers engineered E.
Coli bacteria that glow when they encounter vapors from buried
land mines and other unexploded devices. It turns out that

(06:17):
all land mines leak explosive vapors that build up in
the soil directly above these devices. The living bacteria are
placed inside tiny polymer beads that drones then scatter across
the minefields. When they encounter the land mines's emissions, the
bacteria begin to fluoresce, and the researchers can use a

(06:38):
laser based system to map the terrain and identify danger zones.
Once the land mines have been found, specially trained humans
are still the most effective at disarming them, though robots
have also been engineered for the task. Meanwhile, other researchers
in other labs are tackling whole other problems, like shortages

(06:59):
of blood for transfusions. So, okay, humans have various blood types.
If you need a transfusion, say you're injured in an
accident or you're in the operating room awaiting a procedure,
you need the right type of blood, either the same
type as your own or type O negative, which is
considered universal, which means that everyone's body will accept it.

(07:23):
You can't give someone a transfusion of just any old
type of blood. Because red blood cells come with different
types of sugar molecules on their surface, and this is
what makes transfusions troublesome. Type B blood, for example, naturally
contains antibodies that will make your immune system attack the
sugars that occur on type A blood cells and vice versa,

(07:45):
and you do not want your immune system attacking your
new blood. Type O blood has neither of these sugars
on its surface, so it isn't attacked by anyone's immune system,
which is why Type O is in such great demand.
So some researchers out of Vancouver figured that if they
could destroy those pesky sugars, they could create typo blood

(08:07):
from any type of blood. And to find that weapon
of sugary destruction, we're going to have to go back
into your gut. In the walls of our intestines, there
are bacteria known to feed on similar sugars. So the
researchers got some samples of poop, isolated the bacteria, sequenced
their DNA, and found the genetic code for the enzymes

(08:29):
that the bacteria used to break down those sugars when
they eat them, and it worked. Research is ongoing to
make sure it's safe and scalable, but this could help
make blood shortages a thing of the past. A side
note here, I've been talking a lot today about genetic engineering,
which is a little bit controversial in some circles, mostly

(08:51):
due to fears and misunderstandings about what it entails. But
the thing is, it's just a technology. Can it be
used to a response. Sure. Like any tool, genetic engineering
can be used for good or ill. Like the same
telephone technology that keeps you in touch with your grandma
can also be used to scam your grandma. Genetic engineering

(09:14):
is just another type of tool, and it can be
used for awesome stuff or to scam grandma. But okay,
back to bacteria. Of course, not all of them are helpful.
Figuring out how to deal with ones that can make
us sick is tricky because they're generally really good at
what they do, and again, their strength is in numbers

(09:35):
and in quick life cycles. In the course of a
human lifetime, generations upon generations of bacteria can evolutionarily adapt
to resist our best weapons against them, like antibiotics. So
as you may have heard, traditional antibiotics are becoming less
effective at helping us stop bacterial infections. Antibiotics work by

(09:58):
slowing down or killing bacteria to the point that your
immune system can fight off an infection. But the specific
ways that a lot of the classics work tend to
be easily foiled by evolution. For example, lots of antibiotics
destroy bacteria by basically poking holes in their outer cell walls.
The critter's stronger cell walls survive and multiply, and future

(10:20):
generations aren't as likely to be harmed by poking. This
is a major problem because, okay, look, humans only discovered
antibiotics in nineteen twenty eight, less than one hundred years ago.
The ability of antibiotics to fight bacterial disease seemed so
rad that for decades we threw them at everything, even

(10:41):
mild infections, or to prevent possible infections in healthy farm animals,
or as a placebo in patients who had viral infections
yet demanded medicine. That's how we've wound up with antibiotic
resistant infections like methylne resistance Straphylococcus aureus also called MRS
because that's a lot easier to say. This is a

(11:03):
germ that used to just cause skin infections but can
now be deadly in hospital patients. So scientists are looking
into all kinds of new sources of antibiotics that might
work in different ways, like compounds that they've isolated from
cockroach brains or frog skin or platypus milk. I would
not kid you about platypus milk. But researchers are also

(11:26):
talking about switching from the brute force tactics of antibiotics
to actually outsmarting bacteria. But okay, how do you outsmart
something that doesn't have a brain or even a cell nucleus.
It turns out that despite all of this, bacteria do
communicate with each other. They're not texting emoji. This is

(11:48):
called quorum sensing. A quorum is the minimum number of
team members that you need to get something done, like
play basketball, or turn on or off different bits of
genetic code that might, for example, make a bacterium more
or less virulent to an infected host, or maybe it
makes the bacterium form a protective spores around itself. A

(12:12):
bacteria can sense a quorum through signaling molecules. These are
called autoinducers. The bacteria create and then emit them, either
passively or actively, depending on the situation, and so as
the bacterial population grows, so does the concentration of autoinducers
in their environment. Once it reaches a concentration detectable by

(12:35):
the bacteria, the signal is received and the bacteria make
a change for the good of themselves and the colony.
Also a fun and or terrifying fact, bacteria are not
limited to communicating with their own species. Some of these
signals work among different species of bacteria. This isn't always cooperative.

(12:56):
Some bacteria seem to engage in quorum sensing space pionage
while competing for resources. Anyway, lots of different research teams
are studying quorum sensing and looking for ways to disrupt
it or to artificially stimulate it in order to pass
false information around bacterial colonies. So they're looking into the
chemicals and enzymes used in the process, plus mechanisms that

(13:20):
bacteria have for creating and detecting them. But okay, all
of the bacterial shenanigans that we have discussed so far
today are happening right under, or on or in our noses.
But there are whole other bacterial worlds out there, and
one of them is deep under our own. An international

(13:42):
group of over a thousand scientists spent ten years uncovering
the secrets of deep life, a stunningly diverse population of
microscopic organisms miles inside Earth's surface. Some of those bacteria
and other mostly single celled organisms, live off of little
more than the energy of surrounding rocks and can survive

(14:03):
in temperatures hotter than boiling water. The project is called
Deep Carbon Observatory, and it aims to understand how carbon,
of this element that is essential to life as we
know it, forms and moves within the Earth. They estimate
the amount of carbon underneath the surface is hundreds of
times more than the carbon in every human being combined.

(14:27):
During the course of their studies, the scientists drilled over
one and a half miles that's two and a half
kilometers into the seafloor. They captured samples and mines and
boreholes from depths more than twice that. They took the
data from hundreds of sites to get an idea of
one ecosystem in subterranean rock. Looks like the biosphere that

(14:48):
they've uncovered is thought to be twice the volume of
all of our oceans. This new world underneath the surface
may be even more diverse than life on Earth. Yet
these might robes are nothing like life on Earth. Many
have life cycles measured in geologic terms. The implications of

(15:08):
these findings are wide ranging. These organisms can live and
thrive in highly pressurized environments with few nutrients, and in
temperatures that would kill organisms on the surface. They may
now give us clues about the possibility of life in
other areas, including on other planets. But on this world,

(15:29):
where we, again, unfortunately often try to exterminate all bacteria.
A team of scientists is designing a germ bank where
microbes can be stored out of harm's way and possibly
used to ward off disease in the future. The vault's
official name is the Microbiotic Vault. It would be used
to preserve microbes that are at risk of being wiped

(15:52):
off the planet as civilization moves into areas where nature
once ruled. Microbes that we don't even know about yet,
and catalog variants of more familiar ones. After all, the
bacteria in and around us have co evolved with us
for hundreds of thousands of years. They help us make
our food and digest our food. They can help us

(16:13):
manufacture life saving medicines and discover new solutions to all
kinds of problems. The least we can do is return
the favor because we have so much more to learn
from them. Today's episode is based on a number of
articles on HowStuffWorks dot com, including using glowing bacteria and

(16:34):
lasers to detect landlines written by Loreel Dove. How close
are we to creating a universal blood type? Written by
John Donovan, How do bacteria Communicate? Written by Molly Edmunds.
Ten weirdest sources for antibiotics written by Patrick J. Kiger,
And scientists call for a Global germ Bank written by
Chris Opford. But there's also some additional material written by me.

(16:56):
For more about how bacteria poop makes our food, check
out my other podcast as Saver and Hey, thanks to
iHeartRadio for the opportunity to visit iheartland in the metaverse,
which gave me the excuse to write this strange script.
Brain Stuff is producted of iHeartRadio in partnership with Houstifforks
dot com. It is produced by Tyler klang A. Four
more podcasts from my heart Radio. Visit the iHeartRadio app,

(17:19):
Apple Podcasts, or wherever you listen to your favorite shows.

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