Professor Ted Dinan on The Psychobiotic Revolution: Mood Food and the New Science of The Gut Brain Connection

Hey guys, Cribbing Govenda from the Gut Health Gurus podcast. I've got a background in food science and my colleague James Shadarak next to me has got a background in psychology. And we've got a fascinating guest today. I'm so excited to have him on because you would have heard my past podcast around the Gut brain, all my struggles of anxiety and depression. And I've got one of the thought leaders in the space of gut and brain, and his name is Professor Ted Dinan, all the way from Ireland. Ted, thank you so much for coming onto the podcast with us.

My pleasure, my pleasure.

And what I typically like to ask, just to set the scene for our audience. The question is, who is Ted Diamond?

Right. Well, I'm based in Cork now and I grew up in Cork. I'm a professor of psychiatry here in the university. After leaving medical school I left Ireland and I went to New York and spent some time in New York. I then went, was in two different medical schools in London, was back in Dublin for my first, I suppose, faculty position in Trinity College in Dublin. I then went back to London. I was head of neuroscience in one of the medical schools in London. And then about 15 years ago I came back to my hometown in Cork. So I'm a principal investigator in an institute here in Cork called APC Microbiome Ireland, where we work on the microbiota and I teach psychiatry to medical students as well.

That's a fascinating and very interesting background that you have, Ted. Now you mentioned something very interesting to me. So you mentioned that you kind of teach psychiatry. So how did you stumble upon the gut?

Indeed? My background is very much in pharmacology, I suppose, and brain pharmacology. But when I went to Trinity College in Dublin, which is a long, long while back, I was in my early 30s at the time. One of the gastroenterologists there, Knapp Keeling is his name, he's retired now. But Knapp was very much interested in the brain, got access and he persuaded me that it was an important area for understanding various psychological processes and for understanding gastrointestinal diseases like irritable bowel syndrome as well. So I became interest in it at that stage, but it was never my primary area of research. It was more a sideline. When I was in London, I published a few papers in the area. But when I returned to Cork 15 years ago, one of the real strengths in the university here is microbiology. We have some really heavy hitting microbiologists here and I began collaborating with them and I Suppose it's really only about 50 years ago that when people talk about the brain gut axis, that they included microbes. Because when I was doing research in it, you know, 20, 30 years ago, it was just the brain, gut and the way they connect. But we never considered the microbiota. We didn't consider microbes at all. But of course, when I began collaborating with microbiologists, understandably, they were interested in bacteria and more recently in viruses as well within the gut. So we began to explore what is now, I suppose, internationally termed the brain gut microbiota axis.

That's absolutely fascinating. I guess the science around the microbiome is a relatively young field as well. But it's amazing how you've managed to piece together, you know, the gut, the microbiota, the brain, and you, from what I'm reading, fact, correct me if I'm wrong, that you coined the term psychobiotics.

Indeed, yeah, that was a term I coined a few years ago. It was in a paper I published in Biological Psychiatry, that particular journal. And, you know, my interest is in, I suppose, modulating the microbiota in order to treat psychiatric illness or perhaps gastrointestinal or other illnesses as well. And within our gut, within the average adult intestine, we have about a kilogram, or slightly more than a kilogram of bacteria. So we've got a lot of bacteria in the intestine, mainly in the large intestine, and those bacteria produce a raft of molecules that our brains and other organs in our body require. So we're very dependent upon that gut microbiota. I mean, it is possible in here, in Cork and other centers as well, it is possible to raise animals who have no microbiota. And when they don't have a microbiota, the brain does not develop normally. And indeed, social functioning, which is a very important part of psychological illnesses, very often social functioning is abnormal in animals who don't have a microbiota. So psychobiotics, yes, I coined the term and it's just one way, just one way of modulating the microbiota. So the question is, how can we impact on the microbiota to improve mental health? And I think psychobiotics is one way and one avenue of potential modulation. So psychobiotics being psychobiotics, are bacteria which, when we ingest them in adequate amounts, have a positive mental health benefit. Now, at the present time, I suppose most of the putative psychobiotics are either bifidobacteria or lactobacilli, and indeed, you know, an enormous range or strains of Bacteria are described as psychobiotic, but in fact don't really have adequate data behind them at all. I mean, one of the big problems in this general area of research is that, you know, a lot of claims are made for bacteria that they're probiotic or whatever. Now in Europe, you know, and I think increasingly in the US as well, but in Europe, the European Food Safety Authority have largely banned use of the term probiotic because it implies that a bacteria can improve health. Whereas in fact a lot of these bacteria that are described as probiotic, there's no evidence that they improve health at all.

Wow, that's, that's amazing. So in terms of the European standards, what's the, the protocol for actually validating.

A claim right now? The, the, the, the, basically, if one is going to make a claim, let's say in an area like irritable bowel syndrome or in an area like anxiety, one needs to produce double blind placebo controlled studies demonstrating efficacy. Most companies that have submitted data to efsa, the European Food Safety Authority for use of the term probiotic, have had their application rejected. And they've had their application rejected because the science has not been up to adequate quality. And you know, when you look at the history of this, the pharmaceutical industry are used to doing high caliber studies because without high caliber studies they can't have their drugs licensed. The food industry on the other hand, has really no great tradition of doing sophisticated research. And of course their margins, their profit margins are relatively low as well. I mean, if you develop a new drug and you put it on the market, you can make a very sums of money on each month's supply. Whereas the margins on a food can be very, very small. They might be 5%, maybe max 10% or whatever. So the margins are small. So understandably the food industry is not often relaxed or they don't feel safe in investing vast amounts of money into a product that they may not be able to get a premium price on. Now having said that, I think that what we're witnessing in recent, the convergence of food and pharma into the same space. And I think that, you know, you will see food companies doing higher grade research and producing products that are natural products, but possibly capable of treating illnesses of various sorts. And I have no doubt that people will be prepared to pay a premium price for those. I mean, you know, as somebody, as a psychiatrist who does clinics all the time, I've seen patients this morning already. A lot of patients who are depressed or suffering from anxiety do not like taking small molecules, antidepressants or whatever, they don't like it. They feel comfortable maybe with psychological interventions like cognitive behavior therapy. But often access to cognitive behavior therapy is not readily available. And it can be, if you're going down the private route, it can be expensive to see a psychologist. So if there were nutritional components that were truly effective for treating anxiety and depression, I think it would give a radical improvement in the choice of therapies for patients. And it would give psychologists and psychiatrists really an exciting new modus operandi in treating psychological disorders.

Absolutely. And we tend to jump around a little bit in that podcast, but I thought we'd take a step backwards and just start to describe for us, Ted, the connection between the gut and the brain, and then we'll come back to what we were talking about.

Indeed. Now, the connections between the gut and the brain are kind of gradually, I suppose, becoming understood. You know, a few years ago, our understanding was rather limited. Now, we do know of certain definite pathways that are highly important. The vagus nerve is a very important route of communication. Of course, it's a bi directional route of communication because signals from the brain can go to the gut. Likewise, signals from the gut go to the brain. So it is very much bi directional. And there are certain bacteria that seem to entirely use this route of communication. I mean, we've shown in some studies that certain bacteria will not communicate with the brain if the vagus nerve is caught. So they require an intact vagus nerve to communicate with the brain. So that's an important route of communication. Another important route of communication is the production of short chain fatty acids. Now, bacteria within the intestine are capable of metabolizing fiber and producing short chain fatty acids. Short chain fatty acids would be molecules such as butyrate, propionate, acetate. These can get into the bloodstream and they can influence organs throughout the body, including the brain. There's suggestions that they may be abnormal. In conditions like autism, the levels may be abnormal. So that's another route of communication. And a third route of communication would be the production of tryptophan. Now, tryptophan is the molecule that gives rise to serotonin in the human brain. And the levels of serotonin have been linked to alterations in mood and so forth. So one of the interesting things about tryptophan is that our brains have very limited capacity for storing tryptophan. We really need a constant dietary supplement supply because we do not store tryptophan in high qualities. So we need tryptophan to be available and to cross the blood brain barrier. And that tryptophan largely comes from two sources. It comes from the diet. I mean, things like bananas and turkey have very high levels of tryptophan. But also bacteria in our intestine like bifidobacteria are capable of synthesizing tryptophan. So tryptophan is another route of communication, a very important route of communication with the brain. And yet another would be the production of molecules from the immune system. Now, the immune system is throughout the body, but there is a very complex immune system in the gut. And these immune molecules, which are called cytokines, can actually travel from the gut to the brain and they can influence brain activity as well. So we have a number of different important routes of communication and they may be working in parallel.

That's absolutely fascinating. I'm staggered about the. The actual ability of certain bacteria to produce tryptophan. Is there understanding of the actual mechanism on how they produce tryptophan?

Yeah, yeah. The pathways within the bifidobacteria have been elucidated. So, you know, they seem to be, you know, there may be other bacteria capable of doing this as well. But the certain, the one bacterial source of tryptophan that's been most extensively studied would be bifidobacteria, which are regarded as, you know, traditionally regarded as probiotic. And of course, you know, in babies, in neonates, young babies, there are very high levels of bifidobacteria. But of course, as we age, the levels of bifidobacteria do decline.

Absolutely. And in terms of bifidobacteria, are there specific strains of bifido that are more capable than others?

Well, certainly in our lab we've worked a lot with particularly one particular strain of Bifidobacteria longum 1714 is the particular strain. And we find that that particular strain, both in animals and in humans, seems to have anti anxiety effects. So ingesting it in quite large amounts seems to have an anti anxiety promoting effect. Now, whether that's due to the fact that it's producing tryptophan or not, we haven't demonstrated that. Although we have demonstrated that if you ingest this particular bacteria that the levels of tryptophan in the bloodstream do increase.

Wow. Yeah. That is staggering. Amazing. So you mentioned anxiety, stress.

Yes.

So how do these, I guess, these compounds that are produced or metabolites assist in actually alleviating these symptoms?

Yeah, I think that, you know, we currently know of two important mechanisms. One is, I suppose, promoting normal Serotonergic transmission centrally. So they promote, you know, the serotonin, you know, regulates a variety of functions. It regulates sleep, it regulates appetite, sexual behavior, and clearly is involved in regulating mood. So I think that providing normal serotonergic transmission and seems to be one very important way in which these bacteria can influence our brains. Another important root, though, also is their capacity to dampen down our stress responses. Now, the core stress axis in man is the hypothalamic pituitary adrenal axis. And many of your listeners will be familiar with cortisol, because cortisol is the main stress hormone in men. And of course, any of us, you know, if we experience stress and stress is part of normal life, cortisol levels become elevated. And of course, in something like depression, if somebody is clinically depressed, cortisol levels can become elevated and sustained and be sustained in an elevated state for quite an extended period of time. And we do know that certain bacteria, I suppose the bifidobacteria, have been the most expensive, extensively studied, are capable of damping down cortisol responses. So they reduce cortisol levels. And that seems to be important in terms of their anti stress effect.

Wow, that is amazing research. Do you have any questions you want to add on to that, James? Not just yet. Not just yet. So it's fascinating now that I guess this excessive amounts of cortisol in the body can translate to stress like behaviors using something like a psychobiotic like bifidobacteria and potentially limit the effect of it. Is that correct to say?

I think that's reasonable to say. There's no doubt about it that, I mean, you know, cortisol is a very important hormone in our bodies and it does a lot of important things in terms of regulating our metabolism and so forth. But excess cortisol production is damaging to our health. I mean, the most extreme example of that would obviously be Cushing's disease, where somebody, because of a pituitary tumor, ends up secreting an enormous amount of cortisol. And it has a very damaging effect on the heart and on other aspects of bodily function. But even in depression, we know cortisol levels can be very, very high. And of course, some people can be depressed over very extended periods of time. I mean, I suppose most people, if they go for treatment, they'll be depressed maybe for several weeks or for a few months. But you do see people, and I see them, my clinic, who've been depressed for maybe a year or two years, which is obviously a very extensive period. And the cortisol there does have negative impact. I mean, we know that people who have suffered from depressive illness are far more likely to have a heart attack in the subsequent years. And that is probably largely driven by heightened cortisol levels. There are lots of longitudinal studies following depressed people over extended periods of time and showing that they have far more heart disease than the general population. So I think that when we're using something like a psychobiotic, and I think we're still in the early stages of developing these products, very, very early st, so one has to be cautious in what one says. But I think that, you know, the ability to give people a greater capacity to deal with stress has long term physical consequences as well, positive physical consequences, because cortisol and as I say, other aspects of the stress response are damaging to our bodies, particularly our cardiovascular system.

And this all resonates very, very true to me. I recall going back when I was suffering from anxiety and depression. They did send me for cortisol testing and it did come out as being elevated pretty much throughout the day. There was no respite in the levels. So that's how they managed to say, well, we've got an issue here in terms of that symptom.

Yes. Yeah, no, that's a finding that kind of. Many people have observed. And what we have observed, I mean, you know, one of the things that we do or have done in my group is we've been following people who've been born by cesarean section as opposed to being delivered per vagina. And it's long been recognized that the microbiota develops differently in those two scenarios, because if a baby is delivered per vagina, as they come through the vagina, they pick up lactobacilli from their mother and that becomes the dominant microbial species for the first year or two, particularly if the baby is subsequently breastfed. But if the baby is delivered by cesarean section, and one basically finds that the bacteria and the microbiota are bacteria that the baby has got from the doctor's skin, the mother's skin, and from the environment at large. And for the first three or four years, that baby has a very different microbiota to the baby born per vagina. There are very different microbiota. Now, that is relevant because cesarean section rates are clearly on the increase globally. In Europe, I suppose, on average, well, it varies somewhat from country to country, but most countries do have in excess of 30% cesarean section rates. The World Health Organization recommends cesarean section rates of about 12%. So we're way over what is regarded as optimal. Of course, in some countries the situation is far worse. I mean, if you look at the scenario, let's say in Brazil, well over 50% of the babies there born are born by cesarean section. The true would be same would be true in Manhattan, in China. Some parts of China have over 80% cesarean section rates. And that is probably due to the one child policy that was followed by the Chinese government for several years. So cesarean section rates are most definitely on the increase. And what are the long term health implications of that? Well, we do know that when you have babies born by cesarean section, they're far more likely to develop asthma and other allergies than babies who were born per vagina. Of course, many babies who are born by cesarean section are also exposed to antibiotics earlier on. And we know that antibiotics exposure early in life greatly increases the risk of obesity in adulthood. So a baby who's had a cesarean section delivery and also has had exposure to antibiotics is far more likely to end up as an obese adult. Now, one of the findings that we've got here, and I wouldn't want to overstate this, but it is certainly a consistent finding, is we've looked at adults who were born by cesarean section and we've looked at adults who've been born per vagina and we find that that adults who were born by cesarean section do have consistently higher stress responses. And we've looked at this in a variety of ways using a variety of stress measures. I'm not saying it's a massive difference, but it is the most definite difference between the cesarean and the vaginally delivered baby, who obviously subsequently is an adult. And we're talking here about adulthood. So initially the microbiota of those two babies is much different. Over the first three to four years they converge. So it's hard to find differences at four years. There may be subtle differences at four years, but I think the first three or four years are pivotal in the development of stress responses. So although the microbiota may have converged at three or four years, the stress responses have developed in a slightly different manner and these differences are persistent into adulthood. Now, one is not in any sense suggesting that we shouldn't be carrying out cesarean sections. Clearly it's a life saving surgical procedure. But I do think that women should be aware of potential consequences like asthma and allergies, the increased risk, and we really need to look at our overall rates, particularly in the west where they have, you know, crept up insidiously in recent decades.

Absolutely. Couldn't agree more. And how about the, I guess, antibiotic usage? Is that factoring into the equation as well?

I think it is. I think that again, you know, we know that there's a lot of, of inappropriate antibiotic usage in adulthood. And I suppose recent meta analyses would say that exposure to antibiotics in adulthood, for instance, does increase the risk of subsequent depressive episodes in the months following antibiotic usage. It certainly alters the microbiota. But interestingly enough, if one is an adult, let's say in one's 20s or 30s, and one is an antibiotic, clearly the antibiotic greatly alters our microbiota. But over the next eight to 12 weeks, the microbiota goes back to what it was previously. So you're not seeing a permanent alteration of the microbiota with antibiotics, but the evidence in children is perhaps somewhat different. If a baby before the age of a year has two or more courses of antibiotics, obviously that alters their microbiota. But we know that the impact of that is to significantly increase the risk of obesity, which is obviously a major health issue globally, but particularly in the West. And we know that the risk of obesity is greatly increased as a result.

Wow, that's staggering. I guess a common treatment for depressive like symptoms going back to, I guess the mental health, health part of this story. So a common story is that they will prescribe some form of antidepressant medication. So how is there any, is there any, I guess, science behind changes in the macabre through the youth camp?

There's nothing published. We have a paper coming out shortly looking at the impact of some commonly used antidepressants on the microbiota. And we have found that commonly used antidepressants like Fluoxetine, Prozac and Venlafaxan, which the trade name in most countries is Effexor, that they radically alter the microbiota. Now, whether this is relevant to their mechanism of action or not, one can only speculate. But we can show, because we've looked at the microbiota pre and post, and undoubtedly these antidepressants do alter the microbiota. Another substance that is used a lot in mood disorder, of course, is lithium. Now it's mainly used, I suppose, in people who are bipolar, but it's sometimes used to potentiate antidepressants in people who are not bipolar, but just simply a severe treatment resistant depression. And lithium likewise does alter the microbiota. Now we showed it must be five or six years ago. Now we showed that Olanzapine, which is mainly used for treating schizophrenia, but in both Europe and North America, is often used as an adjunct for anti depressant therapy in people with more severe forms of depression. Olanzapine, we showed, had a dramatic impact on the microbiota. And certainly our data would suggest that the dramatic impact is the reason as to why olenzapine causes so much weight gain. It tends to be associated with a lot of weight gain. And we showed that you get a big increase in firm acutes and a decrease in bacteroidetes when you, when the olenzapine is ingested. And interestingly enough, it's not from our group, but another group showed that if you take a germ free animal who has no microbiota, olanzapine causes no weight gain at all. So olanzapine only causes weight gain when there are microbes in the intestine. If there are no microbes in the intestine, olanzapine does not result in weight gain.

That's staggering. So that that shift in I guess firmicides and Bacteroides, there's a pretty big groups of, I guess a big phyla. Do you have any data on I guess, more specific genus, class, level?

To be honest, we don't. It's something we're looking at at the moment because, you know, it's been known now for well over a decade that of course obese people do have far more firm relative to Bacteroides. And you know, it has all that if you take an obese individual and you do a transplant from an obese into a lean, that the phenotype of the lean will alter and that lean individual will become obese. And likewise, you know, when you take the microbiota from a lean individual and transplant it into an obese, the obese will tend to lose weight. And I suppose bariatric surgery, which is usually to kind of bypass stomach, which is used for treating morbid obesity. One of the dramatic impacts, of course, of bariatric surgery is that it alters the microbiota. So I think one of the reasons bariatric surgery may be effective is at least partially due to the fact that it produces such a dramatic alteration in the microbiota structure.

That's staggering. And equally with, I guess, the rise of FMTs as well.

Yes, absolutely. Well, I think, you know, the FMTs are being used more and more in gastroenterology departments and I think, you know, gastroenterologists are aware of the major benefits. Of course, if one is treating somebody with C. Difficile. I mean, I Mean, fetal microbiotic transplantation is effective in up to 90% of individuals. But, I mean, there are some hazards. I mean, one of the hazards is obviously being if the donor is obese, that you might be transmitting an obese phenotype to the recipient. But another potential hazard, we had a paper there three or four years ago, and it was called Transferring the Blues. And it's been a fairly cited. It's only three or four years, but it's been cited quite a lot. And one of the things we showed in that is that if we took the microbiota from a depressed patient and we put it into a rat, that that rat's behavior does alter radically. Whereas if the rat gets a transplant of a microbiota from a healthy individual, its behavior doesn't alter at all. But transplant from a depressed patient does alter the behavior and it alters the immunology as well, and it alters the metabolism of tryptophan. So what I always say to gastroenterologists is, okay, it's very. When you're assessing the donor to make sure that they don't have HIV or they don't have Hep C or other viruses that you might be transmitting to the recipient, but that you really have, in my opinion, the donor should be somebody who is free of psychiatric illness because you could end up transmitting a psychiatric phenotype from donor to recipient.

That is such a. An excellent point as, I guess these treatments become more prevalent even in Melbourne, Australia now there's clinics opening up where they do these type of treatments. Yes, that is such a good, I guess, a good warning for the practitioners out there engaging in these types of treatments just to be wary in their questionnaires and their surveys that they're really looking at mental disorders for dotors and screening them as well.

Yeah, I think it is really important because, you know, I mean, a lot of gastroenterologists are very, you know, cognizant of mental health problems, but there are a lot of gastroenterologists who aren't as well and, you know, they may not regard the presence of depression and the donors as being that important. And I think that, you know, caution would suggest that we shouldn't use donors who have a history of recurrent depression.

So we're going to go on a slight tangent now. Ted, what inspired you? You co authored a book.

Yes, well, the three of us have got to put it together. We kind of all have a passion, I suppose, for brain, gut, microbiota access and the potential of that area to deliver improved treatments for Patients with mental health problem. When we published our original article on psychobiotics and defined psychobiotics, the science literature took it up, but the lay press took it up even more vigorously. And, you know, one saw articles in a wide variety of lay journals, from the New Yorker to the Economist. And, you know, so it was a term that seemed to kind of strike a chord with. With the lay public. So it seemed to us that, you know, given that fact, that it would be a good idea to put together a textbook on it and to make it a readable book. I mean, we didn't want, you know, John Cryan and I, you know, we work very closely together. We're mainly published science for scientists. But we wanted to produce something here that was readable and that was geared at the lay public and that wasn't making outlandish claims for things because, you know, it's very easy to make ridiculous claims and of people going out and buying products that don't have any great benefit or merit at all. So, you know, the objective really was to have a kind of a sensible book that was easy to read and gave people, you know, advice about what to eat or not to eat and other ways in which they might be able to improve their mental health.

And just for our listeners, the book is called the Psychobiotic Revolution.

That's correct. Indeed. Yeah, absolutely.

There's a bit more to it. Mood Food and the New Science of the Gut Brain Connection. So we will link to the book in the show notes. So if people are interested in reading and following along the journey, we'll definitely link onto it. You can get it on Amazon or wherever. Book depository. Let's just explore a little bit further into psychobiotics. Psychobiotics. I remember when I watched you speak at the Gut Brain Access in Paris that you mentioned that there was a guy, I think, in 1910 that started.

That's right. I found this to a paper that was delivered to a London audience of physicians back around 1910 or something. And the guy was a psychiatrist. I think he. He was working at the Bedlam Royal Hospital at the time. And, you know, he was suggesting that bacteria, which we would now probably call probiotic, I think he was focusing on lactobacilli, were a way of treating melancholic depression, which, you know, was amazing. Kind of. I know, you know, at the time, you know, the use of fermented foods was being advocated by certain people at the time. But it certainly was kind of a revolutionary idea that somebody might be able to use bacteria for treating melancholic depression. Now, I'm not personally sure that that is correct. I mean, my own view is that if psychobiotics are being developed that it is more likely that they will impact on the milder forms of depression rather than the more severe melancholic forms of depression. And I think that's where the real gap in the market from a commercial perspective or where the real, you know, When you look at people who have severe forms of depression in general, they're happy to receive any form of antidepressant or any form of psychological therapy. If one is severely depressed, one clearly will take anything to relieve it. But of course, if you have milder forms of depression, and milder forms of depression are often rather chronic and they can be quite debilitating. But many, many patients with mild depression are not happy to take antidepressants. They don't like taking antidepressants. And I think if we had more naturally occurring approaches like psychobiotics, and they don't necessarily have to be bacteria, I mean, they could be prebiotics which would stimulate the growth of good bacteria. And you know, if I was to give anyone, and obviously I see a lot of depressed patients, it's primarily what I do in my clinical practice, I. But if I was to give anyone advice who suffers from depression, apart from any psychological or pharmacological input that they might receive, it would be to go on a Mediterranean type diet with a lot of fruit and vegetables, to take their protein in largely in the form of fish and probably chicken, and to keep red meat to a minute and certainly a max once a week. Too much red meat is clearly not good. I think from a mental health perspective, I would also always caution them against processed foods. Trans fats are a major problem. I mean, we know for decades that they're not good for cardiovascular function. It's clear they are not good for mental health either. So I think plenty of, of vegetables and fruit, nuts, keep processed foods to a minimum. And of course, let's not forget aerobic exercise on a regular basis. So I advocate for all my patients five days a week that they, if it's running, they enjoy or swimming or cycling, it doesn't matter what the form of aerobic exercise is. But I'm a big believer that 30 to 40 minutes of aerobic exercise five days a week is one of the most potent and antidepressants available and of course has a dramatic impact on the gut microbiota. We know that aerobic exercise impacts the gut microbiota. Now I know a lot of young kids, and particularly males, go weight training and they spend a lot of time in the gym lifting weights. And there is a suggestion that that's as good for mental health as aerobic exercise. Nonsense, in my opinion. I'm not suggesting that people shouldn't lift weights. If they had the time to stop or do, then that's fine. But I think that aerobic exercise is really vigorous. Aerobic exercise is the antidepressant, really, that we should be getting hold of.

Absolutely. Couldn't agree more. And let's talk a little bit, a bit more about prebiotics, because I did recall from your slides during the presentation that you mentioned a few that you guys were studying at the time.

Yeah, well, there, you know, there are, you know, I suppose one could go buy capsules with things like Foss and gauss and so forth that are prebiotics. And there is evidence from our lab that they are in fact anti anxiety. They have an anti anxiety impact. But you know, I always stress to patients that the best delivery system for any nutrient is good food, not a capsule. And you know, if we want to look at prebiotics, inulin is probably the most widely studied prebiotic. It's in high concentrations in things like celery, bananas, Jerusalem artichoke onions. There are a variety of vegetable sources of inulin. Now, inulin is a fiber, and fiber is obviously good for one's health. But not all fiber is prebiotic. I mean, certain fibers, such as inulin are prebiotic, but not all fibers are prebiotic. But I think overall fiber is good for our mental health. But specifically prebiotic fiber, which promotes the growth of good bacteria.

And I think from the studies I've seen that have a bifidogenic kind of effect.

They do, Absolutely they do. I mean, prebiotics cannot be metabolized by us. I mean, we can't metabolize prebiotics. But of course, certain bacteria and as you say, bifidogenic strains can metabolize these prebiotics and they do stimulate the growth of the prebiotic or else these probiotic bacteria.

Mm. Okay. I think we're coming up to time. Ted, if you wouldn't mind a couple of quick rapid fire questions. We did post in our Facebook group approaching 10,000 people and we asked them. We've got. Professor, there's a few people there that are extremely excited book already and they had a few questions. So I'd probably if I didn't ask you. So the first question is.

What does.

The roadmap for mental health services incorporating Gut brain research, like psychobiotics in a.

Clinical setting look like, I think, you know, unfortunately, right now, any interest in this amongst psychiatrists and psychologists is very limited. I think that nutritional psychiatry, which is really, I suppose the umbrella term for the question, is in a very early stage of development. I do think that as mental health professionals, we should be looking at the diet of our patients and most clinicians do not. I mean, everyone who comes to see me with depression, I do give them dietary advice and I give them advice in relation to exercise. And I think that that is the way things are going, but it is not the things are in general at the moment.

And how do we get there?

Well, I think education of the healthcare professionals to begin with. I think that we need to really incorporate information in relation to nutrition and diet in our training of psychiatrists and psychologists and psychiatric nurses. And that's absent at the moment.

Couldn't agree more. Absolutely. And another question was, how does grains. I think Dr. Pullman wrote a book, was a Grain Brain, about the impacts of, I guess, things like wheat and wheat on the brain.

Yeah, indeed. Absolutely. I think that, you know, there may be other important routes, but I think the main avenue at the moment is that, you know, ingestion of wheat and other grains does promote the growth of good bacteria. There's no doubt about that. Now, the question, you know, there's a paper just published last week, and I was looking at the overall intake of fiber. So not any specific source like grain, but the overall intake of fiber. And there's no doubt about it that that overall mental health and reduced risk of things like Alzheimer's disease is seen in people who take in a lot or high level of fiber. And of course, the fiber intake in most developed countries is way below what it should be. I mean, we should be taking up 30 grams of fiber a day. Most people are taking less than 12.

Sure. I think Dr. Pummel was kind of against the use of. Of, I guess, gluten and things like that. But I see a point about the benefits of fiber also coming from grains. So that makes a lot of sense.

Yeah, I mean, you know, I think there are a lot of people out there with fad diets and people coming in and saying that they're allergic to this, that and the other thing. And of course, some of them may genuinely be, but there are other people then, you know, you know, erroneously believing that they're allergic to things and eliminating. Eliminating certain things from their diet and going on diets that really may not be good for their overall Health going forward, if they persist with those diets long term.

Totally. Couldn't agree more. Things like the fodmaps gaps, they're meant to be like interventions that are meant to be for a short space of time.

Exactly.

Healing was then going back to introducing fiber and things like that back into the diet. So couldn't agree more. So let's keep moving to the next question. So is there any link between stress, I guess an amygdala type response and ibs.

Stress and ibs, absolutely. I think that most sufferers from IBS will tell you that they deteriorate when they're in periods of significant stress. About half of patients diagnosed with irritable bowel syndrome at a gastroenterology clinic have a comorbid depressive illness. So they have IBS plus depression or IBS plus anxiety. So half the population of patients with IBS have a psychiatric illness associated with it. Now that means that half of them don't. But even those who do not have a coma, morbid psychiatric illness, stress makes their symptoms worse.

Absolutely. I think we know inherently when we're not feeling that great in the gut, there's something that stress response, you can typically feel it in the gut. So it makes sense physiologically. And in terms of psychobiotics, is there any specific strains that you'd be recommending people look for if they want to start exploring this area?

To be honest, I'm always reluctant to kind of, I suppose, give a specific recommendation. I think that when it comes to something like irritable bowel syndrome, there are a number of strains out there which have placebo controlled studies demonstrating efficacy. There's a biflongum, the strain I think is 35624. There's very good placebo controlled evidence there and it's on the market, the product and it does seem to be effective in treating the symptoms of irritable bowel syndrome. When it comes to more things like depression or anxiety. There are studies out there, but they are rather limited. So, you know, I would suggest, you know, to people to, you know, if they're suffering from stress related conditions, to maybe look at their diet to begin with rather than taking a supplement with a probiotic to look at their intake of inulin, the fiber, and you know, maybe increase their intake by looking at their overall diet and eating more celery and artichoke and so forth and to try to improve their mental health health in that way. Because I'm a big advocate, as I say that really a good diet is the best way to Deliver nutrients to the brain.

Totally. I could not agree more with you, Ted. I guess we've been so conditioned to look for a pill or supplement to fix our problems. If we can get that foundation of a really good diet, lots of fiber down pat, then that kind of limits the need for looking at things like. At supplements. Like supplements. And in finishing. I like to ask my guests this question. If there was one thing you could do for your mental health, what would it be?

I think the one thing that we can all do for our mental health is take regular exercise. It's the most important thing. There's no doubt about it. I think it is more important than anything else. Aerobic exercise.

That means a lot coming from you, Ted. So taking heed. I hope our audience can take heed. And I wouldn't be doing it justice if I rap without asking the psychology background person if he has any questions. Sure.

Thanks, Ted. This has been absolutely fascinating listening to you. One question I had is just in terms of your own diet, your own habits and things that you do to promote good health, to promote good mental health, what does that look like for you? Well, I think that it's only recently, I suppose, I've become interested in the whole issue of nutrition and mental health. And I do think that my diet is off, altered. I think that I'm eating a far wider range of green vegetables and fruit and I eat nuts now more than I would have ever previously. I think there. So I think my diet, you know, has altered. I am taking in more fiber and as I say, eating a broader range of fruit and veg. And I do, you know, eat a lot of yogurt and other fermented foods. But so, yes, I think my own diet definitely has changed. I've always been into exercise since I've been a kid. I run. I kind of run a marathon every year. So exercise is nothing new for me. But my diet has altered, definitely.

Awesome. You're in great shape, Ted.

Well, I'm trying to be anywhere to look after yourself, you know.

Thank you so much for your time.

My pleasure, lads.

My pleasure to have a person your credentials on our podcast. Talking about mental health and gut has just made my year 2019.

Thank you. It was my pleasure.

Thank you.

Listen, take care and have a good day.

Awesome. Thanks, Tim.

Bye.

Bye.