Are We Too Clean? with Professor Brett Finlay

Here’s a little known secret: germs are good for you. Every single one of us has a complex and unique microbiome that lives on us and in us. It’s made up of microbes—things like bacteria and protozoa. Our microbiome plays a huge role in our health and, as microbiologist and University of British Columbia professor Brett Finlay has discovered, it is even connected to non-communicable illnesses like asthma or cardiovascular disease. That’s why pandemic-bred habits like cleaning surfaces with antibacterial wipes, or chronic use of hand sanitizer, can be so problematic: they kill bad germs, and good ones, too. Which prompts the question: is our COVID-caused mania for germ killing messing up our microbiome? In conversation with Medcan chief medical officer Dr. Peter Nord, Prof. Finlay answers these questions—and more.

https://www.eatmovethinkpodcast.com/podcast/ep-69-finlay-microbiome

Links

You can find Brett Finlay on Twitter. 

Read the paper he lead-authored for PNAS on the hygiene hypothesis, COVID-19 and its impact on the human microbiome here. 

He’s also written two books: The Whole-Body Microbiome, co-written with gerontologist (and his daughter) Jessica M. Finlay, and Let Them Eat Dirt. 

Watch this interview with Finlay, in which he discusses building a healthy gut microbiome.

Check out “Can We Learn to Live with Germs Again?,” a New York Times feature on the human microbiome and the need to get comfortable with being exposed to bacteria. 

 

Insights

Our path to slowly damaging our microbiomes started 125 years ago, back when Robert Koch and Louis Pasteur made their seminal discoveries (that microbes caused disease, and that killing microbes could kill disease, respectively). These discoveries lead to sanitation, hygiene, antibiotics and vaccines — which, to be clear, are all good things. But what scientists eventually realized is that when we try to kill microbes, we kill all of them, even the ones that make our microbiomes healthy. This led to David Strachan’s hygiene hypothesis, which essentially argues that we live too cleanly and that the rise of things like allergies and asthma are linked to our reduced exposure to germs. [Time code: 03:25]

 

According to Finlay, newer research has found that microbes actually have an influence over non-communicable illnesses, like cardiovascular disease, too. For example, people who are born via C-section—and are therefore not exposed to the same microbes associated with vaginal delivery—have a 25 percent higher chance of getting asthma; they also have a 30 percent higher chance of being obese. “There’s actually quite a tight link,” he says. “It’s a fascinating thinking experiment.” Some research even indicates that your environment and proximity to people plays a part in your microbial health—that’s why spousal rates of inflammatory bowel disease are actually pretty high, even though you are, of course, not related to your partner. In other words? Be careful who you’re kissing.  [Time code: 08:29] COVID has changed all of us—microbiomes included. We shy away from close contact with people, we’ve been (necessarily) wearing PPE for a long time now, and we’ve mostly been inside for the past year, meaning we’ve been exposed to far less germs than we normally would have been. Finlay worries that this will have the biggest impact on children and the elderly, when microbes have the largest effects on our overall health, which could lead to higher rates of things like asthma and obesity in the coming years.  [Time code: 15:20]

We’ve all been a bit more hyper-aware of our hygiene during the pandemic, but Finlay cautions against letting our changed behaviours become permanent habits. Of course, we should all continue to follow public guidelines, socially distance and wear PPE as long as the risk of COVID remains high. But if you’re still wiping down your groceries or Amazon packages, it’s long past time to stop that—disinfectant wipes don’t stop the spread of COVID, anyway. And during non-pandemic times, Finlay’s hand-washing rule is simple: “I generally say soap and water before dinner, but lay off the hand sanitizer. All it does is kill the good microbes on your skin.”  [Time code: 21:13]So what can we do to fix our microbiomes? Luckily, there are a few things. First, is eating well; Finlay recommends a Mediterranean-style diet that’s full of fruits, vegetables and legumes, and low on dairy, fat and sugar. Next is getting outside—don’t be afraid to let your kids roll around in the grass or get a little dirt under your fingernails. You probably won’t be surprised to learn that exercising has a beneficial effect too, as it can increase your anti-inflammatory microbes. And you need to lower your stress levels, too, as stress can actually cause an inflammatory response in your microbes that can lead to other diseases. “Post-COVID, chill out,” Finlay says. “Just sit back, play with the kids, go outside and eat well, and maybe you’ll add a decade to your life.”  [Time code: 22:54]

And if you take probiotics—or you’re tempted to start—know that they likely won’t have a big overall effect on your microbiome. Finlay compares them to trying to find a new pair of running shoes: you walk into a store and are bombarded by options. You don’t just grab the cheapest pair and then walk out. Because probiotics are not regulated, companies tend to be looser about the claims they’re making. “We just have to realize we’ve impacted our microbes and realize that there are things we can do to help them, because they’re our friends and they’re going to help us down the line,” Finlay says.  [Time code: 27:44]