Are Your Kids Too Clean? (Pedcast)

Voice intro:

Welcome to another edition of Portable Practical Pediatrics. I’m your host, Dr. Paul Smolen, also known as Doc Smo. From the bassinet to the board room, if the topic involves children, we talk about it here. I frequently get asked by the parents of my patients, “Why do so many children have food allergy, asthma, and eczema today? Most of these parents don’t remember their friends having nearly the incidence of allergy that today’s children do and that was just a few decades ago. What is going on, they ask? Well, my answer is that we really don’t know, but we are beginning to get closer to an answer. For years, immunologists and allergists have been talking about something called the Hygiene Hypothesis to explain all of this allergy. Recent observations have made this less of a theory and more of an explanation. Experts are beginning to have some understanding. So in today’s pedcast, I thought we would talk about some of this evidence and introduce you to the current thinking about allergies and children. The hope is if we can understand what is driving the allergy epidemic, we can help protect future kids from suffering from with terrible allergies.

Music Intro:

Life for Children has Changed Drastically:

I grew up in a typical middle class family where there was a premium given to being clean. My mother was always telling me to go take a bath, wash behind your ears, and use soap!  She believed that you couldn’t be too clean. Dirt and germs were the great enemy to her generation. Keep the children squeaky clean, their food, their water, and you are bound to have no disease… right?  Since germs were known to cause much of the disease in children, the less germs there were around, the less disease they will have- or so goes the thinking.  It’s logical and this approach worked for about a 1/2 century. But as infectious diseases started to disappear, here comes another type of disease…allergic disease.

Today’s children are now faced with a tsunami of allergic disease. What has changed in just a few generations?  The answer is a lot! When I was a kid, we literally lived outdoors. We had almost no access to television, computers, video games, or other “indoor” kid activities. No, we lived outdoors unless the weather was extreme. And a large part of that outdoor experience was dirt. My childhood was filled with tire swings, mud pies, wading in creeks, rolling in the grass, and pushing toy soldiers and model cars around in the dirt. I was filthy at the end of everyday. Rarely did I take an antibiotic and if I did it was a very low potency medication, I ate very little processed food with preservatives, I ate food off dishes that were washed by hand at low temperatures, my food was washed but not irradiated, and of course, I was outdoors most of my childhood playing in the dirt.

What is the link between dirt and health?

Researchers are finding that modern life is having an impact on the bacteria in your child’s intestines, on their skin, and in their noses. This is very important since it turns out that having  a healthy variety of good bacteria is essential to your child’s immune system functioning well. Imagine that, your child’s poop is actually vital to their good health! How ironic. Modern life seems to be changing today’s children’s gut and skin bacteria (the so called microbiome) and this seems to be driving the allergy epidemic. Many physicians think that the change in your child’s bacteria, has changed the way their immune systems react to the world creating nonsense reactions like peanut allergy. That’s the essence of the hygiene hypothesis in a nutshell.  But why are we seeing this in children and not so much in adults you might be wondering? Aren’t the microbiomes of adults changing too? Researchers speculate that infancy and childhood are when a human’s immune system is fine tuned, not during adult life and that’s the reason why.  Additionally, children have much stronger immune reactions than do adults. Without children having these reactions to the many infections presented to them, most children would simply not survive their childhoods.  Having a strong immune system used to mean survival for children of the past but today, it has been all too often transformed into asthma, food allergy, and skin allergy called eczema.  Long time listeners of Doc will recognize the theme. We have been talking about this for years on Portable Practical Pediatrics. So, the hygiene hypothesis predicts that any factors that change the diversity or quantity of bacteria that children carry, is likely to make them more likely to have an out of control immune response that are not only not useful for the child, but are dangerous to their health; converting their previously life saving immune responses into things like peanut allergy, grass pollen allergy, bronchospasm  and asthma when the weather changes.

Evidence that the Hygiene Hypothesis is Correct

Let’s go over the evidence that has been mounting that supports the hygiene hypothesis in the past few years. Here is what the research has told us:

-Children who grow up on farms, around more dirt and animal waste, have less allergic disease than those who don’t. Additionally,growing up with an animal living in the house, lessens a child’s chance of allergy

-Eating off dishes that are cleaned in a dishwasher rather than being hand washed, increases a child’s chance of allergy

-Being born in a more sterile manner, i.e. by C-Section, increases a child’s chance of allergy.

-The more courses of antibiotics, especially broad spectrum antibiotics a child receives, especially when the child is very young, the higher the chance of them having allergic disease.

-The more highly processed food a child consumes, the more likely they will demonstrate allergic diseases.

-Pregnant mothers who take probiotics in the last trimester of pregnancy have children with 1/2 as much allergy as moms who don’t take the probiotics.

What Can You Do to Lower Your Children’s Chance of Allergy?

What are we to do with all this information you ask?  Well, here is some practical advice from Doc Smo, that is relevant for your parenting, especially if you have a family history of allergies. Based on what we know today, here are the things you can do for your kids to increase their chance of a life without hay fever, asthma, food allergy, or eczema. During pregnancy, eat as little processed food and as much cultured food as possible. And take probiotics, especially in the third trimester of the pregnancy. Work with your obstetrician to do everything possible to avoid having a C-Section. If possible, have your family live with a family pet, or even better yet, let your kids live or visit a farm frequently. Hand wash your dishes whenever possible. This is less convenient but it avoids the high temperature sterilization of your dishes. Do your best to avoid your child taking antibiotics, especially strong broad spectrum antibiotics, in the first years of life. Try alternative treatment approaches whenever possible. Your pediatrician can help with this. Avoid feeding your children processed food whenever possible.  And finally and maybe the most important thing, have your children spend their childhoods outdoors, playing in the dirt!  Maybe keeping them squeaky clean all the time isn’t so good for them. Time will tell.


This is your host, Doc Smo, saying thanks for making Portable Practical Pediatrics such a huge success. I truly love bringing you the latest health news about children and hopefully, helping you keep them healthy!. If you enjoy learning about pediatric health with pedcasts, take a minute to subscribe on my website, or on the iTunes. And don’t forget to send your comments and insights to my blog. We would love to hear from you.  The staff at docsmo, hopes this podcast can help you put the squeezes, on your child’s wheezes. Until next time.

Edited by  Monica Miller MD, FAAP

Smo Notes

  1. Cesarean versus Vaginal Delivery: Long term infant outcomes and the Hygiene Hypothesis
  2. Irradiated foods in US
  3. Contaminated foods-
  4. Facts about irradiated foods-
  5. Lots of antibiotics and stronger meds.