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[Music]
let's start by refreshing
memories in reminiscence of a time when
we were striving to build computation
devices from technical modules with Def
functions to perform complex
operations in reminiscence of a time
after that when we were seeking to
create
self-replicating sustainable systems
from biological bricks to understand
life in reminiscence of a time after
that when we were aiming at the
optimization of our own life based on
trillions of foreign cells bacteria in
inside
us that time is
now and with this a warm welcome to all
of you thanks for coming I'm really
thrilled to be here I'm excited to be
here it's my first Congress uh
unfortunately I have been sick I brought
you some of the bacteria we're going to
talk about uh but now I'm here I'm happy
to be here no no no hold your applause
please we don't have time uh as said I'm
I'm Lawrence um I'm coming to you from
the Mah vitman inov in beautiful Israel
um I'm happy to be here in this
wonderful city liik um and I want to
talk to you about hacking the human
microbiome and I want to do this by
answering four very essential questions
the first is of course what is the human
microbiome second of all after I
introduced some general concepts of the
human microbiome I want to tell you how
we study the human microbiome what
technologies we apply here and why this
is all relevant to all of
us then I want to answer the question
whether there is a hype in public media
about the human microbiome and whether
this at all is
Justified lastly I want to also look
into this glass ball into the future and
want to ask okay what's next what's next
in hacking the human microbiome again
very relevant to all of us but let's uh
go right into media's race and ask the
question okay what is the human microbio
and in order to answer that question I
want to start with some very
straightforward maths uh with a figure
and number that you probably all know I
guess you know it's free billion but
what's free
billion any guesses fre billion if you
hear fre billion what comes to your mind
it's not your income unfortunately no
it's the size of the human genome it's
the length of the sequence of the
genetic code of a human being these
letters some of you I've given you here
Define this
human being here this chabby guy and you
see it's in blue so it serves as a blue
blueprint of of us as human beings but
the question is is that all given this
sequence information is this all that
makes us us that makes us human or is
there more to that more than this
sequence well in fact there is more
because we are not just human we are
also bacteria here's one one
bacterium and also this bacterium
contains genetic information you see it
looks a bit different now it's green not
blue apparently and it's also less
complex so instead of three billion
letters it only contains round about uh
5
million and now you may say okay so
these three billion letters that Define
us as human beings it's just 3 billion
letters for one single human being right
but within us there's not a single kind
of bacterium there's many hundreds some
estimates even say thousands so this
complex letter assemble we have to even
multiply by hundreds or thousands to get
the complexity of all bacteria that live
inside us that make us now you may say
okay but we as human beings we're also
complex you know we are not just one
human cell we have lung cells heart
cells some people even have brain cells
so if you sum them all up um we get a
number of around 40 trillion okay we
have 40 trillion
cells on the other hand we have to admit
that there's also not just a thousand
different kinds of bacteria but there
are many in terms of numbers that even
outnumber at Le or at least level the
numbers of human cells so we also have
40 trillion bacteria inside us uh which
is all published and you can look up if
you don't trust me um and if we want to
play this numbers game here we should be
further more precise because from these
40 trillion human cells that we contain
80% of them we should not
consider because they don't contain any
DNA anymore they don't contain any of
this genetic information because they
are just red blood cells
they they are just sacks of of
hemoglobin without any genetic
information okay so the human cells are
much less complex in terms of genetic
information um and maybe one last math
trick here to understand the complexity
of these bacteria we have to take the
sum we have to take all of them all that
live inside us with all their genetic
complexity sum up to what we call the
human
microbiome now no matter how you do this
number crunching one thing is for sure
this is really complex and to understand
it requires a lot of
thinking so putting all this math aside
again in a nutshell the human microbiome
is all bacteria that live inside us well
at least if we consider ourselves human
beings but even if you more think you
know I'm more like a robot or something
bacteria also grow on very sterile
surfaces like metal surfaces of very
sophisticated and suppos to be sterile
engines so even robots do have a
microbiome but let's stick to the human
microbiome okay I'm saying the human
microbiome are all bacteria that live
inside us and I stress the in but that's
actually not true because they are also
living on us if we look where we can
find
bacteria living together with human
beings making us human beings we find
them on the skin we find them in our
mouth in the airwaves we might even find
them in our spinal cords can you imagine
that bacteria in our nerves maybe in our
brain dictating what we think how we
behave is that even possible well I put
a question mark there and we will come
back to this later on um most of the
bacteria as a matter of fact do reside
in our gastrointestinal tract so in our
stomach and in the intestine in the
colon and so forth and this is very
fortunate because they are easily
accessible usually we can access them in
a very frequent manner if we go to the
toilet we sort of flush most of them
out um but no matter if you look in the
toilet or on other sides these bacteria
that you find that compos the human
microbiome as a matter of fact are a
very Complex Community they are very
diverse and I don't know what you think
but for us as scientists diversity is
something very positive it's very
intriguing it's very valuable because
it's inspiring something new we are not
afraid of something new we can learn
something from something new and we are
open-minded and looking for diversity
and that's what we can find in the human
microbiome and these bacteria are so
diverse because they are highly adapted
so in evolution they adapted to very
specific niches and became very
different from each other and to depict
this diversity of the human microbiome I
show here four examples of these
bacteria okay they are very different
for instance you have a blue one which
has some fella some sort of tails that
it can Propel to swim then you have the
purple one which has like a spiral shape
you have an elliptic one which is rather
reddish and you have an orange one that
has a like a spher shape so just in
terms of their morphology how they look
from the outside they seem to be very
different however there's one
characteristic that they all share
remember they are microbes so what they
share is their common size in size
they're around about I mean in terms of
orders of magnitude they are one
micrometer in length one micrometer is
one met divided by 1 million so they are
very small of course some are just like
half a micrometer some are more like
five but on that scale they all operate
no matter how they look that's why they
are microbes why they make up the
microbiome they are living biome okay
and they are microbes small rather
small um but uh despite this common size
as I said the morphology is very
different and then we can just look at
the morphology and try to form groups
among these microbes okay and then we
say yeah the the red one and the orange
one they look rather similar so they are
more evolutionarily related and then
this group of bacteria is more related
than to the spiral-shaped one and only
then they are like related or ancestors
share common ancestors with the blue one
and all of them of course go back to one
common origin the uh common ancestor of
all these bacteria the bacterium that
was there at first and this origin uh of
course is the source of this entire
diversity that nowadays lives inside
us but here's the concept in biology
that you need to know uh form follows
function so every structure that we find
is intimately related to a function in
biology so the spiral shaped bacterium
has a spiral shape for a certain purpose
okay and so does the rod shaped blue
bacterium has its shape for a certain
purpose so how do they functionally
differ these bacteria
and to understand that now you already
managed like onethird of my talk let's
all together just take a deep
breath okay there's even a phone buzzing
this is also a function that could
discriminate but in this case the
ability to breathe air to live from Air
differs between these bacteria okay so
only two out of four can basically live
with oxygen how come well some of these
bacteria are somewhere hidden in our
stomach so they are never exposed to
oxygen they can live without it for them
oxygen is even toxic but some of them
are exposed to oxygen so they evolve
towards using the oxygen for their for
their metabolism and their
life um what else do we have what how
how else are we as humans for instance
different from each other um well when
it comes to nutrition uh are there any
vegans in the audience now you may argue
that um they are not yet an entire
different species uh but with eating
habits comes a lot of you know
differences uh and also you know there's
people that like a chunk and there is no
well never mind so anyways they have
they have preferences in terms of uh
dietary habits so there is some bacteria
that can process sugars where others
cannot and there is some bacteria that
can process fatty acids short chain
fatty acids longchain fatty acids
unsaturated fatty acids and so forth and
some others cannot and based on this if
we look at these properties we could
again assign some sort of similarity
Matrix and then say okay we have like
one group of bacteria and another group
of bacteria and they are all very
different from each other but with these
differences also come
interdependencies potential modes of
interactions how these bacteria also
depend on one another right they have to
interact with each other that's like a
payoff of diversity as well you have
very different interaction partners that
you can harness for your own benefits so
let's look at the interdependencies of
these
bacteria if we have them here we could
in general hypothesize that they all
interact now in general we have like a
rough understanding how bacteria
interact but for every specific PE pair
of bacteria it's quite tricky so there's
many question marks many open questions
here but again in general we we can
derive some some overarching principles
how these interactions and
interdependencies work for instance
there is one set of bacteria that can
process the ice cream that we are
eating okay on the Other Extreme there's
another subset of bacteria again living
inside us the human microbiome that can
process the sushi we are eating whereas
the others cannot and while processing
Sushi now the blue bacterium generates
small molecules that the other bacteria
need to fuel their engines or even to
build up their engines and these output
molecules that it creates after
processing Sushi I depicted here as
gears okay because gears really fulfill
this concept that they can fuel an
engine itself or they can build up
another Machinery that can drive
metabolic processes and make these
bacteria alive inside
us and this sort of input output
relation a bacterium that consumes Sushi
and produces a gear can also on a
conceptional level help us to better
understand some phenomena we see in
these bacteria now as very technical
devices right as some some sort of
processing units so if we have now one
processing unit one of these bacteria
that processes one unit of sushi it
generates one unit of gear okay and now
comes an amazing property if we wait
just a short while and expose this one
unit of bacteria with another single
unit of sushi it produces two units of
gear okay so this bacteria these
bacteria just as this Congress has the
ability of refreshing memories it
remembers okay I was exposed to one unit
of sushi and it can add it to the one
unit of sushi it is exposed right now
and produce two as a sum of one and
one however this property this memory
function does not last infinitely long
so if we wait long enough and we now
expose this bacterium to to three units
of sushi it produces three units of gear
and this is amazing because it this
means that it was reset to zero and is
still sensitive to large amounts of
sushi just imagine you would expose your
bacteria your gut microbiome to three
units of sushi but as an output you
would only get two units of Gears this
would not be healthy in the long run so
fortunately these bacteria can adapt
which means that they are still
sensitive even to large excessive
numbers of input without again losing
their ability to respond uh
properly and this is even on a molecular
level for some of these uh input output
relations it's not sushi but it's some
amino acids so rather simple it's very
well understood and I even published
this in my bachelor's thesis when I
simulate swarming behavior of these
bacteria and uh in the Journal of
Unsolved questions okay so we can even
make very small contributions to the
field now these features of refreshing
memory adaptation and so forth translate
now to a dynamic behavior of these
bacteria so they change with time right
they grow they die they change in
numbers inside us right while we are
breathing here while we are listening to
this talk and this Dynamic Behavior we
can also from this Dynamic Behavior we
can also derive common principles so if
we look now at the amount of these four
bacteria over time first of all let's
look at the extremes okay so there's
always some bacteria that just die for
instance the orange one it just gets ex
extinct with time the Other Extreme
there's one bacterium that is not really
there in the beginning but then it
outperforms in terms of growth all the
other bacteria and it dominates the
culture or our human microbiome with
time it just outgrows all the others so
it just increases the amount with time
that's the purple one but then there's
also some let's say intermediate
phenomena for instance the red bacterium
it just flu flates with time but among
these fluctuations which could in fact
be very low maybe we cannot even detect
them we cannot even measure them it's
rather stable it always stays around the
same level okay so this is some sort of
stability feature so even if we now try
to perturb this bacterium we would not
succeed because it's very robust in a
sense and then there's a feature that
you may know if you already encountered
let's say the kids Corners around here
it's a phenomenon called resilience and
this means basically one bacterium is
basically pushed away it's it cannot
grow for for a certain time because
maybe another bacterium takes away all
the sushi that it would like would it
that it would like to consume but then
it you know takes keeps calm takes some
rest takes a deep breath and then it
decides to regrow it's also some sort of
memory because it remembers where it was
coming from but this this ability to
persist even strong perturbations you
know even if you're being pushed out of
the sandbox you just go to your daddy
and cry but then you go back okay that's
resilience and also bacteria do
this um however what is important here
if we now look at the end of our
experiment to identify what kind of
bacteria and what amount like to which
amounts we have them uh inside us
usually it's just a relative measure so
we cannot really measure absolute number
of bacteria counting them individually
but we can only say okay we have a lot
of for sure at the end we have a lot of
purple ones and we have very few of the
orange ones but it's only in relation to
each other okay so this also makes it
hard to compare between different
individuals let's say between me and and
you so what what kind of Technologies do
we have to first of all identify these
bacteria and then also tell more about
like how many of these we have what
techniques do we have to study the human
microbiome this is our next question and
I've already outlined to you where we
have a good source of the human
microbiome in the
toilet so what we are doing all day in
essence is we are extracting feces okay
we take feces either from mice or from
humans and then we take bacteria out of
these feces and put them into a petri
dish for instance here we took the
orange bacterium out of the feces and
put them into a petri dish where it has
some growth media like all the nutrients
it likes the sushi or whatever to grow
but to know whether this is the orange
bacterium or the purple one or any other
we have to test certain growth
conditions let's assume we know about
this bacterium whether it grows on in
the presence of certain substances or
not then we can just expose it to these
conditions to see whether it's indeed
the bacterium we think it is and that's
exactly what has been done so we take
these bacteria out of the feil samples
and then put them on plates under
different conditions for instance there
is one plate where there's no Oxygen
and also no sugar but then there's a
plate where we do have oxygen but no
sugar and so forth so if you want this
is like a the truth table of the of the
human microbiome okay because then if we
put the feces on these plates we see
okay if we don't have neither oxygen nor
sugar in the top left corner we have
just a few bacteria but if there's no
Oxygen but there's sugar we have many of
these bacteria so now we can check okay
which bacteria are known to grow in
absence of oxygen but in presence of
sugar and then we can boil it down and
we can idea okay so there must be an
orange bacterium in this feil
sample there's two problems with that
first it's not as simple because usually
it's not sufficient to just test two
conditions usually we do test 128
conditions and of course this Matrix is
much more complex then but even this
Matrix is not enough because there is no
unique assignment of these conditions to
individual bacterial strains individual
bacterial species and also this is not a
black and white picture does this
bacterium really do not grow in absence
of sugar I mean we have some of these
bacteria there right so maybe we need
some more sophisticated means and more
sophisticated means we go back to the
genetic information we crack open these
bacteria and look at the genetic code of
these bacteria and we apply a technology
that is called shotgun sequencing and by
shotgun sequencing we mean that we
fragment this genetic information into
small pieces just as the bullets of a
shotgun are scattered when shooting I
didn't invent this terminology and then
we have then we basically read these
small fragments and have to put them
back together in like a jigsaw puzzle
okay and once we have the entire
sequence back uh in one piece we have to
check okay does this now look like one
bacterium or the other bacterium so we
have to find a good match um just in any
dating app that doesn't work uh this is
also a non-trivial task because you can
argue about the reference sequence that
we have but you know with a certain
probability we can now say okay that's
the green bacterium here we can infer we
can predict what we sequenced here in
this fil sample must be the green
bacterium but it's not just one piece of
genetic information we cannot only say
it's this bacterium we can also say okay
we find here many many gears uh that are
needed so apart from the bacterium
itself we can also more look like for
functions that are carried out and can
even put them together uh to more
complex assembly lines uh for instance
the sushi processing
pathway now another note in terms of
complexity of course this is does not
just happen with the genetic information
of a single bacterium there is hundreds
of bacteria as I already told you so
here we are not looking at a simple
genome but a higher assembly of genomes
which we call metag genome okay which
requires sophisticated means of
computation also to den noise the signal
and so forth
because if we look at the data that is
generated by this sequencing approach it
basically looks like this it's a very
sparse Matrix so here we have like for
every gear that we can detect based on
the genetic information and every sample
that we sequence like every feil sample
every stool sample we mostly get na
which is not available there was nothing
detected does it mean that this gear
that this bacterium this genetic
information was not there or was it just
too low to be recognized
so this very sparse Matrix is very hard
to interpret we need very good models to
discern the true positives from the
false positives and the true negatives
from the false negatives and this brings
us back to one of our initial questions
bacteria in the brain If We Now find a
certain signal a certain sequence of a
bacterium in a fluid from the spinal
cord does it really mean the bacterium
is there no it's an indication but it
can be a false positive and therefore
this is still being uh discussed in the
scientific Community largely whether
this is really
true so in order to be certain whether
some bacteria are really there of course
we can do this in a huge cohort and look
for something uh very easy to relate to
for instance obesity okay so we take
stool samples from lean and obese
patients and then we analyze them by
means that I just introduced to you so
we sequence these feil samples and then
we get an idea of which bacteria are
inside there okay now from looking at
this kind of data it seems like okay the
orange bacterium is more abundant in the
lean human and the purple bacterium is
more abundant in the obese bacterium but
again this is just relative maybe one is
just pushing out the other is it the
absence of one or the presence of the
other that really makes us lean or obese
well first what you can do you can take
all these bacteria that we identified by
sequencing in these tool samples and
look at them as features okay in a in an
N dimensional feature space if you
sequenced n different bacterial uh
species you identified n different
bacterial species you have an
n-dimensional feature space and then you
can reduce dimensions and ask the
question well can I really separate the
obese ones from the lean ones and I mean
it looks like we have some decent
separation okay so you can ask okay what
are the features that discriminate the
lean from the obese which bacteria make
us lean or obese and then if you find
some bacteria that contribute to this
you can basically look uh how they
correlate so you put all the um body
weights of your participants in this
clinical trial um on one axis and the
amount of the bacterium that you
detected in this case the orange one on
the other axis and as you have already
learned most of the entries are zero
because you cannot detect it but for the
others you see some sort of trend so it
seems like there's a negative
correlation between the presence of this
bacterium and your body weight meaning
if you have more of this bacterium you
are leaner okay so this is maybe some
bacterium that you want but of course
you can also do like more sophisticated
approaches here this is just some rank
based correlations so you could also you
know train a like a decision tree and
some classifier do some machine learning
stuff that you probably know better than
I do but in the end does the patient
care about whether this is correlation
or really cause well maybe it gives us a
hint what to try and anyways it is what
it is so um what we want is we want to
find bacteria that we can use for
rational intervention that we can use to
really now help these obese patients to
become leaner or the
lean uh persons to stay lean okay uh
and what what can we do about this at
the moment if you look at the media
there is quite a hype and there is one
central question that comes to me or
that should come to all of us when we
see something that is being hyped in
public
media why I mean why is this relevant to
us well if we have bacteria that make us
leaner faster
smarter we tend towards like self-
optimization and it's something very
easy to try right to optimize ourselves
so uh if we look at the media we can
read well there's a contribution to our
eating habits Fitness States
suceptibility for infections aging
cancer Etc PP you can do the search for
your own if you just type microbiome in
your favorite search engine you will
find it um there is one quote I brought
you from an Israeli um journalist who
said he said in Hebrew but I brought you
translation yesterday I interviewed the
respected scientist of the computation
biology field who told me that the best
diet for obese people is eating poop of
lean people and let their gut microbiome
work okay so this is a straightforward
suggestion if you type in your favorite
search engine how to eat poop you will
find what to do like microwave it filter
it but let's take a step back okay let's
see what what we can do
um the funny thing is you can do all
kind of mathematical operations with
your microbiome you can subtract so you
have your set of bacteria in your gut
okay that you want to optimize you can
take antibiotics that just eradicate
some of the bacteria probably most of
them but some Will Survive and you
pretty much know uh a priori which are
resistant to these bacteria and which
not uh you can also do something more
targeted which is like swallowing
viruses for bacteria that are very
specific that may just eradicate like a
single bacterium and all the others will
survive but you can also multi multiply
bacteria for instance assume you already
have bacteria that do you good you're
lean and you just want to get a boost so
you can just take what is known as
prebiotics which are basically
metabolites for instance like the sushi
that some bacteria need to grow so you
swallow that and your bacteria will
multiply and you will have plenty of
them another option is like a simple
addition this is now the option of
eating poop okay right you just take
stool samples from from a healthy person
and you consume them and the bacteria
inside
inside this poop will then also be
inside you and do their job will keep
you lean or whatever uh you can also
take certain yogurts or mixtures which
are known as probiotics to just get some
of these bacteria like very defined
species that are supposed to be healthy
in whatever sense or there's also some
sort of vaccination where assume it's
not the bacterium itself not the living
bacterium but just some molecules on the
surface of the bacterium that stimulate
our body cells to do something healthy
that stimulate our immune system or
something so you basically heat
inactivate um the poop um or maybe you
add these specific parts that you
already know that do good some of the
gears right from the sushi and then you
just inject them with a
vaccination um which will also I mean
kill most of the bacteria in due to the
heat um but we'll probably give you
these one specific pieces that you need
to stay
healthy the last mathematical operation
missing is the division um which is some
sort of fasting so by just drinking
water you basically wash out all the
substances that the bacteria need to
grow and they will be diluted themselves
and you will be remaining with just a
few bacteria and maybe all the bad ones
are just
gone okay so this is the options we have
at hand now what to do with this in the
future is it advisible to hack our human
microbiome at this uh state of the art
in science
um I only want to provide you with a
single slide on that and just give a few
um advices
here because it's on you it's on all of
us to decide right it's on on the
society we can just provide some
guidance so here's some guidance uh from
my point of
view do-it-yourself biology is very
tempting we really like it in Germany we
have some legal constraints here um but
genetic engineering of bacteria is much
much more simple than you hear even now
in the days of crisper C where you can
genetically engineer human cells
bacterial to engineer bacterial says the
technology is 40 years old everybody
knows it it's very
straightforward however there are safety
concerns whenever we engineer bacteria
be it bacteria inside us from in from
the inside of us or other
bacteria it's becoming a genetically
modified organism We are Becoming
genetically uh modified organism I I'm
not not saying it's a bad thing I'm just
saying uh we have to consider bios
safety first
okay um then we've mentioned the human
gen the genetic information about human
the human genome this is some very
personal data right that is according to
German laws very neatly protected but
what about our metag genome is this not
also part of our identity I'm raising
this question here because the German
ethics council is not discussing this
even though again all the technology is
been there for decades we have to have
this
debate how to store this data how to
encrypt it this has never been discussed
and the time for this is really now um
what about patenting genetic sequences
we cannot patent our own genome but what
about the Genome of the bacteria inside
us it's a legal Gray Zone to all that I
know we have to think about
this what if I only know the sequence of
some bacteria that inside me but other
people don't we have to share these
sequences to to learn something from
this so in a nutshell and to cut a long
story short what we can learn from this
the human microbiome has a lot of
potential but there are also some
threats and the only way to deal with
them is together right we have to talk
to each other to exchange information
and only then make an educated decision
how to handle this whether and how to
hack the human microbiome and before I
arrive at the final slide I just would
like to thank um basically the
foundation that allowed me to to come
here to that covers my travel expenses
but of course all the organizers here I
think it's again it's my first but it's
the best Congress right I I ever
attended um the vites man Institute uh
is is a beautiful place to to do science
we are very open so please uh feel uh
warmly welcome whenever you are like uh
in the vicinity just drop by um and then
last not
least let's end by refreshing
Memories the human microbiome is a
complex Ensemble of bacteria with
nonintuitive interactions and
interdependencies we are exploring
mechanisms of Regulation through hacking
by rational interference under
controlled
conditions individuals
single people companies try to
monopolize technology knowledge and data
constraining free and open research
rendering the potential of hacking the
human microbiome a threat through
uneducated
trials friends that time is over now
thank you very
much
thanks for the excellent talk we now
have about 5 minutes for questions you
know the drill line up the microphones
and please keep it short because we are
a bit short on time microphone number
two
please thank you for your talk I just
wanted to ask you if you can give us
some examples of therapies uh that are
used already with the bacteria maybe
some examples yeah um there's there's a
huge variety of what has already been
done so we just now understood that
there's for instance some bacteria that
metabolize Cancer drugs so there
basically what has been done now uh in
addition to uh the cancer treatment is
like
um there is antibiotics being given to
eradicate basically the bacteria that
could metabolize the cancer drug and uh
and uh therefore I mean once the
bacteria metabolize the cancer drug it
will not be effective anymore so this is
where like uh the eradication of some
bacterial species uh benefits the the
cancer treatment um then there is the
treatment of gronn disease which is done
with the bacterial
supplements uh especially in the US this
is already more uh conventional in
Germany the legal situation is a bit
more constrained let's say so all these
things are just in the beginning we are
starting to understand and I think
there's many to come in the years
following but again there's just a few
examples where this is already uh been
done in the clinics apart from this
there are small clinical trials in terms
of research studies where this has been
done but again it's a very wide field
and I think it's just yet to start
thanks mic number four please uh it's a
simple question um nowadays it is hard
to get the proper information because
there time of fake news fakes
information where should I be educated
about the you know micro trium nowadays
the proper research yes so good question
um the I think the best source of
information is actually the origin where
it's generated so talk to the scientists
that's why I put this hashtag cycom
their science communication ask people
who are doing it they know their stuff
sometimes they are you know they're good
scientists they're not the best people
to communicate but that's something we
as scientists have to learn right so
don't be afraid and really approach them
that's I think it's Our obligation and
our duty uh to share this information so
go right to these people and approach
them and they should uh provide you with
all the information you need I think
this simple direct Pa thank you thank
you number one please uh yeah hi um you
made a link between obesity and your
microbiome in in your stomach and so on
uh how do you know you're looking at the
right Point here and that you're not
mixing cause and effect yeah
uh that's a very valid point in fact
there is many mechanistic studies as we
uh put it so there is there were some
bacteria which were associated with
weight gain for instance and targeted
depletion of these bacteria showed that
um basically the weight gain is reduced
and then you can basically also turn it
around and say okay if I now for
instance you to uh food restriction in
man or in mice if I lose weight does
this bacterium go away like is there
what is the relationship and this has
all been done and as I already indicated
in the case of obesity we even one step
further so it's not only that we
identified bacteria but we also
identified molecules these bacteria are
producing that help us to uh for
instance uh keep our weight or or stop
regaining weight after weight loss and
stuff like this so here we have very
detailed information and are very uh we
have very solid evidence on um these
bacteria and these molecule however I
have have to State usually scientists
report very modestly they say okay we
have a certain confidence here we have
certain uncertainty and then this goes
to public media and there's of course a
huge headline like we only need to
swallow poop to get lean but again I
wanted to tell you it's more complex
than that but again in this particular
case we have a very solid understanding
I feel thanks right thank you okay one
last hopefully short question from
number three please uh hi it's a bit on
the same topic as the question before
but what is the relation between
microbiome and polygenic
scores polygenic scores yeah like for
instance uh Robert plumin recently
published a book on like showing that
obesity is mainly genetic that the uh
that uh the relationship yeah is mainly
caused by like uh many genes and there
is this concept of polygenic scores MH
yes I'm happy to elaborate on this I'm
afraid it will um time will not allow
but you're happy to come here and then
we can uh elaborate on this in a private
chat thanks a lot fair enough perfect
thank our speaker again
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