It may seem like we are contradicting ourselves by sharing this article, but, in fact, we completely agree that our bodies require contact with both health-empowering bacteria (like the flora needed for digestion) and immune-building bacteria…the stuff that makes us sick for a little while but stronger in the long run.

In general, we agree that disinfection on a daily basis can lead to limits on the natural immune-building bacterial contact referred to by Dr. Caplan; in fact, we address this early in our book Modern Cleaning: The Evolution of Chemical Free Cleaning. But the assumption that disinfecting kitchens and bathrooms is damaging our children’s health is misleading. More bacteria and germs live in higher concentrations on door knobs, light switches, drawer pulls, refrigerator handles, and other “high touch zones” than in the bathroom or the kitchen. Go ahead and disinfect those areas; the bacteria like salmonella and e. coli are not part of the arsenal of bacteria that help build the immune system.

Think about how much time is spent in those rooms each day? Between your morning routine, a few visits during the day, and an evening routine, you might spend a 60-90 minutes a day in the bathroom, which is the single most human bacteria-laden area of a home. The kitchen comes in second because of the bacteria from live foods…primarily meat and dairy products and residues on fresh produce.

The sheer load of bacteria in these two rooms is more than the body can handle if it is not managed on some level. While certainly some home owners desire disinfection on a daily basis (yes, we have some customers like this), here’s all you need to keep a healthy home that both minimizes risk of the more life-threatening bacteria-based illnesses and still enables immunity-building:

  • perform or have performed a thorough house cleaning on a weekly (most frequent) or bi-weekly (least frequent) basis; this includes a thorough dry dust and soil removal with a true HEPA or similar filtration vacuum and disinfection of bathroom(s) and kitchen
  • wipe down food prep surfaces before and after food prep with a new, clean cloth each time
  • keep bathroom and kitchen surfaces dry when not in use—water is prime real estate for bacteria, germs, and viruses to grow in

Here’s the first key: NONE of this provides a sterile home environment. In fact, that’s not even possible without a very expensive “clean room” system.

Here’s the second key: no one cleans or disinfects the backyard swing set, tree house, basketball court, football field, neighborhood playground, or any of the other places where children of all ages can come into contact with and contract their regular childhood illness. Though our homes may provide higher concentrations of some common bacteria, the outdoor environment provides a wider variety of naturally-occurring immunity boosters to bring into the home on a regular basis.

Send your kids out to play and get dirty. Yep, we definitely agree with that!

In praise of germs: Why common bugs are necessary for kids

By Art Caplan, Ph.D.

Attention, germaphobes. Exposure to the microscopic bugs is crucial for keeping kids healthy, according to new research in the prestigious journal Science. The study strongly supports a growing body of evidence that you need to put away the disinfectant and expose children to the real world of germs and microbes.

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We’re meant to encounter some microbes and dirt when we’re young. It’s how we build our immune systems.

Scientists Richard S. Blumberg and Dennis L. Kasper and a team of researchers at Harvard Medical School showed that in mice exposure to germs in early life helped reduce the body’s inventory of invariant natural killer T (iNKT) cells. These cells help protect us against diseases like inflammatory bowel disease and asthma. But, if there are too many of them with too much time on their hands, they can actually cause these conditions. By exposing young mice to common microbes the scientists saw that the animals were protected from accumulating T cells — and were healthier than those who were not. 

The scientists reached an admittedly geeky conclusion: “These results indicate that age-sensitive contact with commensal microbes is critical for establishing mucosal iNKT cell tolerance to later environmental exposures,” they wrote in the journal Science. In other words, exposing baby mice to common germs got their immune systems appropriately busy and able to not over-react when encountering nasty bugs and other biological stuff later in life.

This is a big deal.

The rapid rise in food allergies, asthma and other immunological diseases is due, at least in part, to our modern obsession with cleanliness, scientists increasingly believe. The ‘hygiene hypothesis’, first advanced in 1989 by the British epidemiologist David Strachan, contends that these diseases are becoming more common because young children are not exposed to them at an early age. We spend so effort trying to prevent exposure to germs with antibiotics, antibacterials and soaps that letting kids get dirty seems like a violation of basic parental duty.

Parents are constantly being told to make their kitchens spotless, to kill 99.9 per cent of the germs lurking in their bathrooms and to wash themselves and their babies all the time.

This world of purity sounds good but it does not fit how we are designed. We are meant to encounter some microbes and dirt when we are young. It is how we built our immune systems. We need a certain amount of grunginess as kids to be healthy adults.

As the Harvard study shows, filth can be good — at least in tiny amounts when you are very young.

Arthur Caplan, Ph.D., is a Professor in the Department of Medical Ethics and Health Policy at the University of Pennsylvania