Germs and babies – Can exposure be a good thing?

Could germs really be good for babies?

Lately, it seems like everyone is talking about germs and babies.

The weird thing is that most of the conversation is a little different than the way that I remember it eight years ago with my first two children. These days you are more likely to hear about over-sanitation, over-sterilization, allergies, asthma, and auto-immune disorders than you are about trying to keep your kids safe from germs. In fact, studies have shown that more people are dealing with allergies than there were a couple of decades ago.

As it turns out, all of the newest research is pointing to the fact that most people are probably over-protecting their children from many ‘good germs’ that could actually be beneficial for their overall health and development.

Who knew?

So now, instead of asking “How can I sanitize every square inch of my house?” you should probably be asking “Should I let my baby play in the dirt?.” With Summer approaching, this I thought this would be a good time to take a journey together to answer that last question.

Germs and babies

When it comes to babies and germs, it gets a little complicated.

There has been a lot of discussion about the so-called ‘hygiene hypothesis’ that suggests we are keeping things too clean in general and that this lack of exposure to germs is hampering our immune systems over time, leading to higher rates of allergies, asthma, and auto-immune disorders than there used to be.

So, does that mean we should start rubbing raw chicken on our children to let the salmonella get their immune systems ‘revved’ up for action? Should we run around looking for babysitters that also happen to be vomiting uncontrollably?

No, that’s ridiculous.


Of course it is you crazy person!

As this study explains, the term ‘hygiene hypothesis’ can be a little misleading and we shouldn’t assume that this means exposing our babies to any germ we can get our hands on. It’s not really a ‘survival of the fittest’ or ‘what doesn’t kill you makes you stronger’ sort of argument here.

To be clear, I think intentionally exposing your baby to dangerous illnesses and germs is irresponsible and criminal.

Rather, that we should take care to let them have as much exposure to ‘good germs and microbes’ as possible while avoiding all of the bad stuff. This also, by the way, includes things like:

  • Natural childbirth
  • Breastfeeding
  • Increased social exposure (sports and other group play)
  • Less indoor time in general
  • A diverse diet that includes probiotic foods
  • Appropriate antibiotic use

Apparently, the relationship that many bacteria and other microorganisms have with the human body can help develop a little baby’s immune system into a powerhouse¬†that will help take care of them long into their adult years.


Should we really be exposing newborns to germs?

Now that we have the basic argument on the table, we’ll look at what exposure to ‘good germs’ looks like for babies in general.

Remember, I’m NOT saying that we should put our babies into dangerous situations involving serious illnesses or anything like that. In the examples I found while researching this question for myself and my family, it looks like positive germ exposure is really anything that gets children out into the natural environment so that they are exposed to a diverse mix of bacteria and microbes so that their immune systems learn how to interact with things they are likely to encounter throughout their lives.

Heck, there are even a bunch of studies showing that sucking on your baby’s pacifier¬†when it falls onto the ground to ‘clean’ it can help prevent allergies. Gross and interesting.

Also, remember that some of this stuff is probably still up for debate. At the heart of the matter is that playing outside and being exposed to different kinds of bacteria and germs has been shown to be a boost for immune system health in many studies.


Examples of ‘good germ exposure’ for babies

Most of the studies I found break into one of these categories:

  • Indoor exposure to dust and bacteria – Exposure to indoor germs is the most frequently discussed topic anytime the ‘hygiene hypothesis’ comes up. The theory is that people are spending more and more time indoors these days and there is also a greater tendency towards over-sanitization in the house. This study found a striking link between homes with higher amounts of and more diverse bacteria and microbes inside the home and reduced frequency of allergic diseases.
  • Indoor exposure to pets and insects – This includes dander from dogs, cats, and mice. It also includes cockroach droppings (Yuck!). Pets also tend to go outside and, you know, roll around in the dirt and then track it back into the flooring and furniture.

Germs and babies dog

  • Outdoor exposure to animals – Since indoor pets are beneficial because they bring the outdoors in, outdoor animals must be good too, right? This study found that babies who were exposed to farm animals within their first year of life were 52 percent less likely to develop asthma later on. Considering that the study involved more than a million children in Sweden over a decade, that’s pretty significant if you ask me.
  • Outdoor exposure to bacteria and microorganisms in soil like worms – Okay this one definitely grosses me out a little. We’re talking about things like microscopic roundworms and hookworms that are pretty commonly found in soil. It turns out that people in more highly industrialized nations tend to wear lots of shoes and don’t play in the dirt often (go figure!). There is mounting evidence that this is causing a rise in inflammatory bowel diseases and general problems with gut health. In cases of normal exposure (chance encounters while rolling around in the dirt), they seem to benefit the immune response in the body because they activate certain cells within the digestive system. Again, this one is weird. In that same study there is also an example of how doctors have used ‘therapeutic doses’ of these worms to treat irritable bowel syndrome and Crohn’s disease. In healthy people with good nutrition, they will typically pass through the system over time without causing harm.

If you want a little more information about outdoor bacteria, check out my post on the benefits of babies eating dirt and other outdoor hijinks!

When to expose babies to germs is as important as what you expose them to

As great as all of this germ exposure sounds, it turns out that there might be a ticking clock on all of the potential benefits that runs out around the age of one. This is a little counter-intuitive for me because I’m thinking that if we are going to be hyper-protective over our children at any point it should be when they are newborns and infants – when they are at their weakest.

Evidence shows, however, that exploring their environment is one way that babies start developing their immune systems past what their mamas gave them. Anyone who has had a baby has surely noticed that once they start transitioning away from breast milk as their sole source of food, they will put literally anything into their mouth and most of the time that is the first thing they do with a new object. This interaction is constantly introducing new bacteria and other microbes into their system, preparing them to deal with the world.

Here are a couple of studies that highlight the importance of exposure before the one year mark:

  • This Science Translational Medicine study from 2015 looks at the development of asthma in children.
  • This study from NCBI highlights a link between frequent courses of antibiotics before the age of one and illness later in childhood.
  • A similar study here notes the link between farm animal exposure, germ exposure, and gut biome before the age of 3 and allergic disorders later in life.


Babies and germs wrap-up

I’ve certainly thrown a lot of information your way.

I highly encourage you to follow those links, read through the information, and come to your own conclusions about all of this stuff.

As for me and my family, I have always had the mindset that ‘a little dirt never hurt’ while my wife leans more towards the ‘sanitize everything’ camp. My hope is that we have a good middle ground that will help ensure the overall health of our children and their immune systems while simultaneously helping them to avoid catching every cold and stomach bug that makes its way through the area.

The good news is that my girls already refuse to put shoes on for almost any reason when they go outside to play so we’re already one step ahead!

Let me know your approach in the comments as well as anything that I might have missed or something that you would like to know more about. Your questions are probably my questions too!

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