THE MICROBIOME SUMMIT : The New Path to Health

Communication System of the Gut-Brain Connection

Dr. Jane Foster, PhD

dr-jane-foster-phd

Dr. Jane Foster, PhD

McMaster University

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Dr. Jane Foster is actively researching the role of immune-brain and gut-brain interactions on neurodevelopment, behaviour, and brain function. In this interview, you will learn about the latest facts on the links between gut and brain disorders like autism, Parkinson’s disease, anxiety and depression – plus some of the challenges and successes that research is having in this area. Dr. Foster will also provide a roadmap of the type of information needed, and what further research needs to be supported in order to solve the mystery of the gut-brain relationship.

  • Tracey:
  • We are here at the University of Toronto with Dr. Jane Foster from the Foster Lab at McMaster University. Thank you for joining me Jane.
  • Jane:
  • Thank you for inviting me.
  • Tracey:
  • Can you explain to us some of this really fascinating research between the gut microbiome and the brain, and brain disorder, specifically autism, Parkinson’s?
  • Jane:
  • Yeah so the gut/brain axis is on emerging area of study linked to neuroscience and psychiatry. One of the areas that there has been a lot of evidence for changes in microbiome or the composition of your gut is in autism. So from some very early work it was one of the first neurodevelopmental disorders that was implicated to have a role with gut disturbances. And what’s interesting about children, some of the children with autism is that their diet is so food restricted that there is a combination of factors that might be at play here. So whether or not they are a good population for manipulations of the microbiome is yet to be seen but certainly there is some evidence of changes in the microbiome in children with autism and possibly in children with other neurodevelopmental disorders. And so it’s important to understand how the microbiota might be influencing their overall health so that we can come up with better treatment strategies for these children.
  • Tracey:
  • Right. So can we now safely say that autism is a gut disorder driven disease state?
  • Jane:
  • No I don’t think so.
  • Tracey:
  • What can we say?
  • Jane:
  • But I would say that, just like other psychiatric illnesses there is probably a subset of children with neurodevelopmental disorders where the gut/brain axis is part of the problem. And so in some cases those will lead to actual functional differences in G.I. function. And in others it might just change the composition in a way they might not have sort of the typical intestinal problems but it still doesn’t mean that the interaction of the gut bacteria with the brain that happens in normal, healthy development isn’t contributing in part to the communication systems between the gut bacteria in the brain in those children. And so it’s important to understand, particularly in neurodevelopmental disorders, what’s the balance between environment and genes in one of the new targets for understanding the environmental component of neurodevelopmental disorders may be the gut bacteria. And also the immune system because the gut bacteria is so important to immune/cell system function. And so really it is a necessary component to understand both the gene and the environmental side of the picture.
  • Tracey:
  • Right, thank you for clarifying that because in the news we see these headlines, Parkinson’s, all in the gut. And we start thinking, what does that mean? So is my Parkinson’s disease caused by my gut microbiome?
  • Jane:
  • Well I think Parkinson’s disease is a very interesting disorder and it’s really just moving forward so fast in a translational way. What’s interesting about Parkinson’s disease, a disease where our particular population of neurons in your brain die, your substantia nigra neurons die, but what happens sometimes before the nigra neurons die is those, that second brain neurons, the enteric neurons, that are important for gut motility, for a whole host of communicating between the gut in the brain, they actually die first so people with Parkinson’s disease will often have G.I. disturbances long before the other symptoms linked to this CNS appear. So what if we could screen and intervene in a risk population based on some sort of gut physiology combined with microbiome? Or even better treat some of the early stage systems from the bottom up. And so people are very excited about this area of research, it’s not an area of my lab but there are a lot of labs around the world and industry partners who are very interested in figuring out what are the bacteria that can increase the longevity of neurons in that enteric nervous system but also in the Parkinson’s disease people, or people at risk for Parkinson’s disease.
  • Tracey:
  • Right, so if you were to create a headline what would it say?
  • Jane:
  • For Parkinson’s disease?
  • Tracey:
  • Yeah.
  • Jane:
  • The brain disorder that starts in the gut.
  • Tracey:
  • Ah, you would, okay.
  • Jane:
  • So, but I would need some evidence to back that up but there is evidence emerging and people are working this both clinically and in animal models so I feel that it’s going to be a big move forward in the next couple of years.
  • Tracey:
  • Right, right. That one, you are very clear-cut on that but autism, depression, anxiety, maybe not so clear-cut.
  • Jane:
  • Yeah I think for those ones the first big translational bang for our buck if we wanted to say, might be in the bio-signature domain so that if we could in fact remove some of the heterogeneity in the patient population even in clinical trials or in our research studies in mental illness so that we have subtypes of patients that are actually biologically based then we actually are going to advance our understanding of what treatments might be good for those individuals or we might identify novel targets for therapy when we start to reduce that heterogeneity.
  • Tracey:
  • Right. This brings me to a question where if you had all the money in the world and you could as a researcher design how the healthcare system worked to treat something like anxiety and depression, what would you see it looking like?
  • Jane:
  • Well I think that as a PhD scientist let’s just be clear, I didn’t go to medical school but within my domain it would be a longitudinal study. It would be a biologically-based longitudinal study where we convince people that these readouts that we use for example at 50 to determine our bone density, we actually do the baseline at 20 and at 10 and so I would take biological samples at a regular interval even if we bank them so that later in life when we understand what the dynamics are, we can go back and have a look to see, was that the starting point? Because I think what we are missing particularly in mental health is causative factors. So really, we don’t have the same readouts as some of, other bodily disorders do and so what we really do need is risk factors to be identified. So I would design a study that went from birth to young adulthood and I would be looking at kids pre-puberty, during adolescence, and in early adulthood. Because we need to know more about how their biology is interacting with their environment in order to change the kids from risk to diagnosis.
  • Tracey:
  • Right, right. What do you think you could sort of give a summary of right now if a parent were to have a child diagnosed with anxiety or depression in terms of their understanding of how to come out this from a multi-disciplinary way of looking at things?
  • Jane:
  • So based on animal research and on clinical studies, mine mostly on the animal side of that, I would say the microbiome is one part but what we know about what benefits anxiety is still the same. Exercise, diet. Stress is a big player. Sleep is a big player that is not often discussed. So I think that it’s difficult to manage those things for your kids. And if you are talking teenagers, the teenage years you know have a whole host of other things going on. Would I probiotic? Yes. I would probiotic my teenagers if I saw a little bit of the stress and anxiety, there is not a downside to it but there is a possible sort of benefit to that probiotic so yes, I would probiotic my kids when they show signs of stress or anxiety or other things like that. I think that the big one that needs to be increased is the exercise component in these kids. Really we have shown in animal models that exercise completely changes, reduces anxiety across the board. And so really, and that’s just recruiting your own system to do the work for you so that would be my best advice I think.
  • Tracey:
  • Right. What about diet?
  • Jane:
  • Diet I think again, it depends you know as we said, or as we know, both diet and our own genetics influences these factors. So I think we have to be aware of the fact that diet is only part of the story. And so certainly we know high fructose, high sugar, high-fat are all not good so we can reduce those things, we can increase our fiber intake which is a good idea. We can increase fruits and vegetables. Those are all overall healthy choices, they are not specific to the brain but certainly there would be important factors and the microbiome would benefit from positive change in those domains.
  • Tracey:
  • Absolutely. I think there is emerging research now to tell us that the microbiome can be thrown into a state of dysbiosis by eating very high fructose, sucralose, I mean all of these artificial sugars, aspartame, things that are just mainstay of the standard North American diet.
  • Jane:
  • Yeah I think the connection that is still to be made is how those are influencing mental health. But we have to think that the connection is there because we know that those affect the microbiome and we know that the microbiome affects mental health so making the full circle is part of what we need to do in the field in the next few years.
  • Tracey:
  • Yeah, exciting research ahead of us.
  • Jane:
  • Yes certainly.
  • Tracey:
  • Thank you so much for sharing all of this information with us.