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hello and welcome to Tentley Speaking where scientists and engineers come together to chat about common interests share knowledge and satisfy some curiosity i'm Laura and I'm joined by Jasmin and Emma to talk about research into gut bacteria and how they influence what goes on in your brain which I think is absolutely amazing but Jasmine why does this interest you i know that your gut and the brain talk to each other cuz like obviously you're hungry your gut
tells your brain to eat something but I was surprised to learn that the bacteria or your microbiome can also have an impact and also talk to your brain especially in the area of food addiction yeah this seems to be some relatively new research that popped up on my news feed i think it was about last year when there was a a bit of a hoo-ha about they'd finally found very convincing evidence that what goes on in your guts can influence how you behave it's all about this gut brain connection which
sounds incredibly complicated and I don't think anyone's gotten to the bottom of it even though it's been studied for quite a long time but Emma I know you work with DNA so I hope you're going to help us interpret some of the research which seems to look at gene expression yeah I mean because like my background is basically like biohysics heavy on the physics recently into the DNA sphere i've had to kind of learn how to interpret different biology papers which
a lot of the time seem to be so many figures and not much explanation to what's actually happening so hopefully I can try and explain some things but I what I do know is because I work with quite a few biologists is and I've had conversations with them about um like your gut health and how uh your gut microbiome actually affects your gut health and your overall health you know there's loads of studies on how it can kind of prevent certain diseases and it's something that is kind of getting
more popular I think in media what people want to try and have good gut health so I feel like I'm not actually surprised that they communicate so much but I still don't think that scientists or especially me understand how that actually happens and how it can kind of affect different cravings that we have but I believe that it can cuz I think there's just so much happening so but no reason why cuz the human body is complicated yeah I think that is definitely so true and uh what I find a
little bit odd about this is I only heard about the gut brain connection recently but it turns out scientists have known about it since around um 1998 I think the first study was reported which is old it's older than me yeah and also when you guys were just talking about how it affects your behavior a lot and food affecting your behavior it just reminded me of the like Snickers tagline which is you're not you when you're hungry and so I don't know if the gut has something to do with that
as well when you get hungry yeah yeah but you know I guess it would um make sense for people that don't know what do we mean by like gut microbiome and gut bacteria so they are good bacteria they're basically bacteria that we want but it's your microbiome is kind of this environment of different organisms as well as bacteria you might have yeast or viruses and it's the diversity in that just like a diversity in farms and like this kind of her immunity aspect of it
you want this high biodiversity for a good gut health although how does a good gut health actually affect our overall health that's the I guess that's the question yeah and from what Jasmine and I were reading into when we were looking at this for cows that produce methane it's really not straightforward there are so many different things inside the guts of an animal that seem to interact in really complicated ways so I guess that ties in with what you were saying
about having a good biodiversity in there but the reason I thought this particular study might be good one to discuss was it popped on newsfeed and it was about a specific class of gut bacteria that had been linked to food addiction as Jasmine mentioned whereas a different class seemed to prevent food addiction so it just seemed incredible to me that your gut bacteria could influence how you behave and particularly how addicted you get to something i think I shared this study
with you guys didn't you did you have a chance to read it yeah the way that they find the correlation is a mixture of brain scans uh but also analyzing some of the um microbiome from and that's from mice who um they were trained to be addicted to chocolate pellets sounds like an odd thing to train a mouse to do yeah but chocolate's addictive and it's for science sounds like they were doing something similar to what we found in the cow gut microbiome study where they basically
analyze the entire genetics of what's going on in there and then correlate that with different types of bacteria or whatever may be in there and seem to find this really clear correlation between certain populations of bacteria and behavior of either mice or people i would also point out that in at least in one of the studies they only did the study on male mice and humans no didn't they explain why though no but I mean that's a lot of science and medicine it's just only men that
does seem a little bit odd in choosing them without justifying it no cuz you'd think you'd want the diversity of the population in there to prove it's not just a specific part of the population oh wait no wait sorry they only male mice but they consider both male and female humans but only male mice don't know why oh well maybe they had their scientific justification it's obvious to people that work in that field but not to people like us who have just come across this thing and thought "Wow
that's interesting i want to learn
more." Yeah i was getting quite um happily distracted by some of the different methods they were using and how like how can you tell if a human feels like they're more addicted to food based on just thoughts and they essentially for the humans I think it was quite hard because they used like this Yale food addiction scale which is like 25 questions that you have to answer and I think they did take samples from the guts of the humans as well to make sure that they'd actually got the
right bacteria there but for the mice they had a bit more of a I don't know training scheme and testing scheme so I was quite intrigued that even though they use these different metrics they were in agreement as well which I think is quite surprising yeah i mean I guess it's not ethical to train a person to be addicted to food so you just have to go with the next best thing well I guess they maybe pre-selected some people that had certain eating behaviors already
yeah but what I found interesting is so they looked at the gut microbiome and they found this correlation between microbiome and behavior and they just went look this is proof it to me is a hardcore scientist that works in the lab i'm like well what's the communication pathway in that case that to me sounds like a correlation not definitive proof of how one thing influences another but I think that is something that they're still trying to figure out cuz right now
they're trying to look at influencing the gut microbiome as a way of treating food addiction which could help with things like obesity and diet related ailments so I think it's more of just like identifying whether or not there could be any connection and then they'll work on trying to figure out what how what's the actual pathway what the actual pathway so from what the gut signals to the brain and what the bacteria impacts are i don't think they're going to figure that out for a
while no it's just what interested me and I thought well exactly how does this happen i'd be more interested in how they use it to treat food addiction cuz I think they identified something in your microbiome that is more prevalent in people who are not food addicted so potentially if you could influence the microbiome to be more rich in that kind of bacteria that could potentially help people with food addiction and what I will say to go back on my whole what is
the actual mechanism and why aren't they telling me I got the impression from what this research group does that their specialism is looking at gene expression in different parts of an organism or a system because some of their previous studies they were looking at gene expression in certain parts of the brain and figuring out that there were some dopamine receptors that were being expressed in um the medial prefrontal cortex I think they said and that was also linked to having an sort addictive
qualities in that person or addictive behaviors so it's like they're tracing all these different aspects of where can addiction be modified using genetics and how can we influence that yeah I did I think I read the same thing on like actually the focus on the brain and the specific like addictive part on the brain and then them trying to control that to see the effects but I feel like I mean maybe this is me not as a biologist that the brain is just so complex and there's so many different
interreationships that if you do suppress one specific part then how do you know something else isn't compensating for it like I feel like there's just so many variables that it's would be really hard to even track any changes that you made i have immense respect for all biologists that do this sort of stuff cuz it just sounds so challenging to pin down just one variable um I mean Emma you're a physicist and I've worked in a lab a lot jasmine you're an engineer so we're used
to being able to control certain variables and seeing what the effect is yeah yeah i mean I also I work um in the lab I work in vitro which basically just means like not in cells so I just look purely at DNA so my work feels very cause and effect whereas if I was to do the same experiment inside a cell I can imagine it would be so different because there's so many different things happening so I'm very glad I work on in vitro things i think that's probably why the argument's heavy on how they're
actually doing these methods and what they're seeing from what they've done rather than a general oh and this then means this is what's happening here i feel like we're sort of we're delving into just how different disciplines work I guess and we started off talking about this gut brain connection which as I say I feel like it's not very well understood so this study has found a cause and an effect and I just I still find it just weird that gut bacteria can
influence your behavior it's like you're not really in control of your body i feel like that's what this study is saying to me you're controlled by what goes on in your guts unlike a dry mass basis isn't the body human body more personal dry mass bacteria than actual human ooh I have never thought about it like that at least that's something I heard i don't know if it's true i just assumed it was cuz the human body is like mostly water i would like to think
it's protein or bone something else to look into uh maybe that's a separate episode are we human or are we just bacteria in our guts jasmine you were talking about how they were using this study to figure out how they could influence food addiction by supplying uh probiotics i I can imagine that at some point in the past people thought that was an absolutely crazy idea cuz how would feeding someone something that doesn't I guess in itself isn't particularly addictive or doesn't have
any sort of medicinal purposes how would that make a difference but for like some other kind of ailments eating probiotics or probiotics is the prescribed way of medicating because if you can promote a healthier gut microbiome does help with overall general health especially with anything related to digestion but yeah I think the evidence is yet to be seen on whether or not if you feed someone some probiotics or you what's the what's it called a fecal fecal transplant oh it
sounds a bit grim yeah I'm waiting to see whether or not they do any like trials for food addiction with this and I'm interested to see what the results would be yeah it's a different way of uh modifying your gut microbiome isn't it by taking the microbiome from someone else and transplanting it doesn't sound pleasant cuz I think your gut microbiome might also have an impact on certain like food allergies or maybe not allergies or sensitivities yeah and this
is because the bacteria and the yeast and the viruses in your gut can help break down food and produce different products of it like I think we mentioned volatile fatty acids in the the cow episode and then your body can use those in different ways i read a similar thing that um different bacteria in your gut can also work together and actually like synthesize vitamins like vitamin B12 is largely synthesized by some of your gut bacteria and so I imagine if you have
like a very diverse got bacteria I don't want to say family cuz that's definitely not right but like community then you may like end up feeling more awake and having these kind of benefits of having higher levels of B12 but actually not know that in yourself and then I feel like it's so hard for a person to be able to track changes of be like okay if I take my yakle every day will I then feel more awake or did I just get better sleep you know I think it's very hard
for us as like everyday people to actually act on a lot of the research yeah also it could just be a be a placebo just because you're taking this yogurt this yakult that's meant to be good for you so you feel better as a result yeah but uh it sounds like there have been a few clinical studies that have been quite thorough about how they've gone about giving people either probiotics or not and it's been like this completely blind studies you don't know what you're getting and a lot of
studies did report maybe not necessarily food addiction but like people were less depressed or less anxious so there does seem to be some science behind it but I'm still not sure i'd just be buying something off the shelf and eating it to improve my mood one of the arguments against using probiotics and probiotics especially like the yogurts is that the bacteria that you want probably won't make it past the stomach cuz it'll just get destroyed by the stomach acid hence
why there's a bit of a trend of DIY fecal implants which I is a terrible idea i'd never heard of those as well like I literally am in complete shock right now and I'm scared to Google and research more oh yeah no don't uh but I would still like being a hardcore scientist someone to explain all the different ways the gut and the brain communicate because there's this something called the entic nervous system so it's basically like nerves connecting your gut to your brains that's one way it can
communicate but you can also have hormones and your immune system can play a part and I can kind of see how your immune system would feature because we're talking about bacteria in your body and your body would normally attack bacteria if it's not meant to be there which then got me wondering about oh when you get a stomach bug and you're starting feeling a bit sick and then you throw up what exactly is going on in your body to make that happen cuz I've never really thought about it i've just
been ill and moved on and also I was reading a lot when I was uh reading about this that when you get like nervous for something and you start to feel a little bit sick how that is something that actually physically happens because it's literally happened to me so many times and I actually don't understand how when I feel stressed or scared for something I start to feel physically ill and like people were saying that that that's one of the major like gut health anxiety relationships is
that it has a massive effect of you being able to actually physically feel the you being stressed which I thought was crazy and I still can't understand it no and then so let's assume that your gut bacteria are playing a part there if you start to feel stressed does that then affect how the gut bacteria will operate like will some of them just stop producing certain chemicals or do they just carry on doing their own independent thing and you've got just your own body's physical effect so your
neurons are firing and making your gut contract or something and that's as far as it goes but even when you say it like that it does sound like something that's so impossible to know because how can you track the motions of like individual cells basically it's a tough job for the microbiologists yeah and I assume it has to be quite an interdiciplinary team so the news story I read that started off this conversation they would they tend to look at gene expression and that's
just one part of what our body does but I guess there are like cell biologists and people that specialize in like looking at what hormones do yeah and even like just the different like you have to get people who are experts in different types of testing as well and that could be all biologists but completely different fields of study and hugely bring them together and communicating between them um it's definitely also a huge task as I've learned in my PhD yeah and then even just analyzing all
the data as well if you got all this gene expression data i think one of the studies mentioned they do something called principal component regression which I remember doing in my masters which is basically like an AI algorithm essentially that figures out patterns and you couldn't really do that yourself you have to get a computer to do it for you but you have to know the technique to apply it and apply it properly which I couldn't do anymore it's been far too
long in addition to like biologists but maybe also people work in the medical field would also be valuable contributor to this kind of research because in addition to studying the actual bacteria in the guts they also use brain scans because they wanted to study how the brain reacted in the addictive versus non addicted mice the way that they try to like link the brain scans is similar to other kind of addictions so things like drugs and alcohol and just like how
the brain reacts it really triggers the reward part of your brain that is a good point this sounds a bit mad but could there possibly be a link between your gut bacteria populations and whether you have like gambling addiction say which has got nothing to do with what you're consuming but is still an addictive behavior if they can figure out how your gut bacteria talks to your brain and makes you addicted to food they may able to use it to treat other kinds of
addictions maybe i still think having come up with this stupid idea it's probably a little bit of a stretch i mean they do say in some of the papers like treat different things besides food addiction so I mean that would be very cool but also I'm going to go back to my first point which was I would believe it i mean maybe if they figure out what the pathway is they can figure out a way to treat my uh addiction to just scrolling through my phone mindlessly
give you a probiotic for that i would love that yes please i'll have one too like we're going down the route of there's basically a pill you could take for any sort of behavior yes we can all become controlled by Oh dear this turning a conspiracy theory is what people put in our water but it's fine cuz it's a bacteria pill it's a healthy bacteria pill it's just promoting certain types of bacteria in your gut so that it is healthier so you do less dangerous behavior perfectly
natural that's fine all natural things are fine like arsenic it's only poisonous in large enough quantities yeah it's naturally occurring it's fine oh dear we've gone down some very weird dystopian future route here just ignore the last two minutes of what we said everyone given that we've gone down this weird dystopian route I feel like that's probably a good place to leave it we're not talking about actual science fact now we're just talking about mad speculation that probably isn't real so
having started off with looking at a study on mice and people that looked at brain activity and gene expression and the gut microbiome that found that behaviors and addiction can be influenced by the microorganisms that live in our gut we've then moved on to talk about some really mad stuff and looked at how it could lead to new ways to help people with addictions and it's really made us wonder about what is really going on in our bodies cuz we're starting to realize that we understand
very little that gives us a lot of scope for future episodes I think yeah I think it does yeah so we'll get our thinking caps on for what exactly we might want to know for future episodes but until then thank you for listening and we'll see you next time the views expressed in this podcast belong entirely to the person that said them they do not represent any industry or organization if you enjoyed listening to these views it would really help us out if you could
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