THE MICROBIOME SUMMIT : The Established Thinking

Hygiene Hypothesis, Antibiotics & Microbes

Dr. Brett Finlay, PhD

dr-brett-finlay-phd

Dr. Brett Finlay, PhD

University of British Columbia

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Overview

Dr. Brett Finlay has published over 460 scientific papers and is the co-author of Let Them Eat Dirt: Saving Our Children from an Oversanitized World. In this interview, Dr. Finlay will talk about the “hygiene hangover” and its impact on our overall health, including the negative impact of antibiotics on our gut health. Dr. Finlay will provide honest facts about the impact of C-section births on the microbiome, as well as helpful tips on how to reintroduce helpful microbes.

Transcript

  • TRACEY:
  • Hi, Brett. Thanks for joining me here today.
  • BRETT:
  • My pleasure.
  • TRACEY:
  • I really enjoyed reading your book, Let Them Eat Dirt: How to Save Your Children from an Oversanitized World. Obviously, you know, your book title is a bit tongue in cheek and the main messages there are really important. What did you want the reader to take away?
  • BRETT:
  • First of all, we’re not saying you should shovel dirt down your kid’s throat at all possible times. I mean, the concept is that we now believe that kids should be exposed to microbes. I call it the hygiene hangover. For the last 100 years we’ve been on this campaign to get rid of microbes through germs that cause disease. You know, 100 years ago, 30 percent of kids would die by the age of one due to infections. Now, 0.1 percent do so very few kids do. That’s spectacular. Kids are doing great now and that’s been a major step forward and that’s because we brought in sanitation, sewers, clean food, clean water, vaccines, antibiotics, all stuff that we know works so well for infection control. So, if clean is good, cleaner is better, right? Well, now we’ve realized in the last five years or so, well maybe not. In our quest to get rid of all these germs, we realize we are really getting rid of all the microbes that we’ve evolved with as a species and we now realize, we didn’t know this before, there’s this profound impact on how we function as an organism. You know, starting very early in life, even pregnancy, these microbes shape how our immune system develops, how our gut develops, how our brain develops, they shift how we eat things and metabolize things and so the main message of the book is really we’ve gotten too clean. We’ve got to ease off on this whole bubble wrapping the kids and let them acquire the microbes that we have evolved with as a species.
  • TRACEY:
  • Absolutely. If we were to explain our microbes as our friends, you know, how exactly are they more friend than foe for us?
  • BRETT:
  • I would say some are friends, some are foes, some could be fickle, some could be really good friends. They come just like all our friends do, you know, in all shapes and sizes. Most people think of microbes as germs and by definition germ means a microbe that can cause disease. There’s only a small number of microbes that actually really cause diseases we know, say, salmonella or e coli O157 or clostridium difficile. These are microbes that really do cause disease in people. Most of the microbes in and on us don’t do that. If, in large doses, if your gut is perforated, for example, normal microbes can seep through and cause inflammation and cause sepsis, but generally speaking they’re not designed to cause disease. They’re just designed to hang out and live in the environment that we call our gut or our skin or, you know, different parts of our body where these microbes are. So, what we know is there’s at least a hundred-trillion microbes in and on us. To put that in perspective, that’s at least as many microbial cells in an on you as human cells. They contain at least 15 times more DNA in different genes than humans do. So, really, in terms of number of genes humans only 7 percent, or 93 percent microbial genes when you add up all the genes on us. This is a really gross way of putting it in perspective; in one gram of feces there’s more microbes in that than there are all the people in the world at any time. So, there’s huge numbers there.
  • TRACEY:
  • Right. And these microbes, they’re working, they’re messaging to our body continuously. Can you explain a little bit how they’re doing that?
  • BRETT:
  • That’s true. They do it in a bunch of different ways. First of all, when you digest food, I mean, we jokingly say you are what you eat. I disagree. You are what your microbes make you. You’re feeding your microbes, not you. So, obviously they can break down food in different ways and that can make different metabolites, can affect people. They interface very closely with the immune system. They can really shape how the immune system works and this is related to, say, allergies and asthma and, you know, those types of areas. And then they can produce molecules that, say, directly affect our body. There’s some studies coming out, these microbes can make molecules that actually affect the brain and they’re actually talking to the brain from the gut. And so, they have all sorts of different sophisticated ways of really interfacing with us and this is how they’ve evolved.
  • TRACEY:
  • In your book, you describe the C-section rates that we have around the world and maybe this isn’t something that we want. We want to try and bring the C-section rates down because the first exposure for all of us is, you know, coming down the vaginal canal. So, what are the current C-section rates around the world and what should we be aiming for?
  • BRETT:
  • Yeah. And, I mean, we first involve that, you know, the very first birthday present you get from your mother I jokingly call the big gulp. That’s a big gulp of vaginal fecal microbes. Birth is a messy business but we now believe that’s actually natural and you actually want to do that. So, in terms of C-sections, Canada is between 20 and 25 percent, which is high. Most numbers say that about 10 percent of women medically need C-sections and so there are a subset of women that are going to have to have the C-section. That’s just the way it is. But we are too high there. Some places in the world it’s insanely high. Brazil has, by far, the highest C-section rate of over 85 percent of women get C-sections there. I mean, 85 percent of these kids being born are not getting the microbes that they actually should be getting because we know that a kid born by C-section, their intestinal microbes are much more similar to mother’s skin than they are to the mother’s vaginal and fecal microbes and we know the vaginal fecal microbes are the ones you want. They’re the ones that help us develop, they’re the ones that help break down breast milk. So, for a whole bunch of reasons, C-section levels can be brought down. Just to elect this because you don’t want to go through the birth, that’s not a good excuse for the kid’s health. Obviously, medically some women need it. Of course you have to do it to save their life or the kid’s life. But I think, yeah, I’ll just have a C-section because it’s cool. In Brazil, it’s very trendy. The obstetricians don’t want to do calls so they just have, you know, your 10 am Monday morning C-section so I don’t have to get up in the middle of the night. So, that is something we have to be aware about because it really does affect these kids’ microbes.
  • TRACEY:
  • As a microbiologist, when you think about the fact that if a child is born via C-section, what message would you want to get out to the practising clinicians and the parents?
  • BRETT:
  • Right. I mean, the message is, I think, you have to somehow realize this kid is starting behind in terms of their microbes. You have to figure out ways you can actually replenish them. So, there’s a lot of probiotics that seem to help to some extent. Both the mother’s diet, even before the kid is born, you know, that plays a big role in shaping the microbes and just any other ways that you can think of allowing your kids to be exposed to these microbes. Breast feeding is terrific. We get a lot more mother’s microbes that way than bottle fed. So, the double whammy born by C-section and then has to bottle feed, these kids are beginning behind the 8-ball in terms of getting fit microbes. There’s a lot of work going on. Recolonizing. There’s things called, you can take a vaginal swab pre-C-section and colonize the kid, you put the swab all over the inside of the kid’s mouth and over their face. There’s concern with that because, of course, the woman has streptococcus which is a terribly infectious agent and you’d be directly inoculating the kid which would be terrible. So, you’d have to be screened for that. But some naturopaths are already doing vaginal colonization by swabs and I think in the future we will see more of that as we determine this actually works. Studies have not proven it actually works. You can recolonize but we don’t know if that’s good or not yet. We have to wait a few years. So, I think just remember that, okay, the kid, you’ve got a little bit of a handicap there. Maybe they can roll around with the dog, hang out with dirt a bit more and, you know, just try and pickup these microbes as they go along.
  • TRACEY:
  • Right. Spend more time in nature?
  • BRETT:
  • Absolutely. I mean, even the fact of living on a farm versus the city. Farm kids have way less levels of allergies and asthma, for example, because they’re exposed to microbes.
  • TRACEY:
  • How should we be viewing antibiotics and what message do you want parents and clinicians to hear?
  • BRETT:
  • So, antibiotics – they’re a wonder drug. If you have a bacterial infection, a serious one. Antibiotics will save your life. If you need an antibiotic for something like that, by all means use it. But what we’ve traditionally not realized about antibiotics is they are a double-edged sword to some extent. Everyone’s heard about antibiotic resistance. We all know about that, increased use leads to resistance. But even physicians are being taught still that antibiotics – well, they might not work but they’re not going to hurt. So, you’ve got a viral ear infection. Yeah, well, take this. It’s probably viral but, you know, it can’t hurt taking these antibiotics. And what study after study after study is showing is that, no, antibiotics basically carpet bomb the microbes. They hit both good bugs and bad bugs equally and so, yeah, you get rid of the thing causing the disease but you also get rid of all these other healthy ones. Repeated antibiotic exposure has been shown to be detrimental to obesity, to asthma, to dementia, to anxiety and stress. I mean, you pick it. So, I think we need a real re-think of antibiotics that …. Yes, use them if they’re needed but realize that there is some side effect to these things and, you know, you’re not going to die from taking an antibiotic. A lot of people die from not taking an antibiotic. But I think down the line we have to realize this has screwed up their microbes and this is going to have long-term health consequences.
  • TRACEY:
  • That’s a really important message. It’s difficult for parents, you know, at the time to sort of push back if they need to. Or even clinicians to sort of, you know, say I feel comfortable watching and waiting.
  • BRETT:
  • Yeah. I mean, my wife’s a pediatrician. You know, it’s three in the morning, the kid’s screaming. Ear pain, what do you do, type of thing? Every parent knows this feeling. But I think pediatricians are, more and more, taking the watch and wait attitude which I think is proper for your infections and the biggest crime with antibiotics is we still, in Canada and the US, use them as growth supplements. In agriculture they will give a 15 percent increase in weight, in pretty much any animal you choose. About 80 percent of antibiotics that are now used in agriculture …. so, there’s a lot of thought because of weight gain in all these different animals, why wouldn’t it cause weight gain in children? So, this may be contributing to the pediatric obesity issues we’re seeing. So, I think we just need to re-think about antibiotics. They’re not perfectly harmless and they do have secondary effects that we didn’t realize before in terms of their collateral damage in all these other microbes. So, there are, again, thoughts that if you do take antibiotics you should think about replenishing your microbes, probiotics, fermented foods, get outside and, you know …. In the book we discuss various helpful hints you might actually use to do this.
  • TRACEY:
  • Your book …. I mean, you really do cover it all. I read it as a clinician but I also was reading it as a parent ….
  • BRETT:
  • Right.
  • TRACEY:
  • …. and I was, like, hmm, you’ve given me a lot of food for thought. Like, things to consider. Absolutely.
  • BRETT:
  • Yeah, that was the main idea.
  • TRACEY:
  • Thank you very much.
  • BRETT:
  • My pleasure.
  • TRACEY:
  • Children that are born via C-section, do they catch up ever? Do we know this?
  • BRETT:
  • For the most part, it certainly helps, like, you can even a few years on tell kids that have been born by C-section versus not. But I think the concern of what I think really scares us all is the fact that, you know, maybe by two or three they’ve caught up for the most part but they’ve already missed that critical development window. So, we know the first few months of life are so critical for the immune system to develop. So, even if you catch up in two years, even in one year, it might be too late. There’s a lot of concern that you eventually might catch up but the damage might already be done. I think that the data is not there either way yet but for asthma and other things that early life window really important one. So, catching up is hard.
  • TRACEY:
  • Yeah, I’m hearing you and it makes me, you know …. Both my children were C-section so I’m like, hmm, I’m listening, right? There are lots of parents and clinicians who are going to be listening and the news isn’t great. However, like you said, there are opportunities further on down the road to have an influence on that microbiome. We just might not be getting it in that crucial 100 days.
  • BRETT:
  • Right. Right, I mean, okay, so you’re born by C-section. That will give you a 20 percent higher chance of getting asthma than if you weren’t. I mean, it’s not to say you’re going to get asthma but it’s just going to put you at a higher risk for this. I think similar numbers hold for obesity, et cetera. I think that early window is important but, you know, you’re not definitely for the rest of your life you don’t do that and, as you say, when the best time to plant an oak tree. Today. And when’s the next best time? Twenty years ago, kind of thing. So, don’t give up even if a kid is born by C-section. Once they show that, still get them exposed to microbes throughout their life.
    TRACEY That’s an important message.
  • BRETT:
  • Mm-hmm.