Why Kids Need Dirt

Katie Wells Avatar

Reading Time: 7 minutes

This post contains affiliate links.

Read my affiliate policy.

Why kids and adults need dirt
Wellness Mama » Blog » Health » Why Kids Need Dirt

Thanks to modern hygiene and sanitation, we have seen lower rates of many diseases and health problems. Unfortunately, too much of a good thing can have its problems. I’ve talked before about how gardeners (statistically) live longer, and it turns out that the dirt itself can play a role in this:

The Problem

We have antibacterial soap, antibacterial spray, antibacterial cleaning wipes and a myriad of disinfecting cleaning products. Kids are growing up in clean, disinfected, sterile environments. We go to great lengths to make sure we are protected from germs. At the same time, we have rising rates of allergies, autoimmune problems and gut related disorders (especially in children).

Could there be a connection?

Some research says yes… In fact, some research says that widespread use of disinfecting and antibacterial products (and removal/avoidance of dirt) is preventing proper formation of healthy gut bacteria and that restoring this beneficial bacteria could be the key to boosting immune function, reducing rates of allergies or digestive problems and even improving mood.

So where are these healthy bacteria and how can we benefit from them? Probiotic rich foods and supplements are a great start, but they are missing an important factor: Soil-Based Organisms (SBOs). These soil based organisms have stronger strains of beneficial bacteria that can survive through the digestive system and provide the most benefit. While fermented foods and probiotic supplements can also be very beneficial, some of these strains do not survive through the digestive system.

Just as the name suggests, soil based organisms are microorganisms found in soil.

Various cultures have known the health benefits of dirt for centuries and there is an old saying that “You have to eat a peck of dirt before you die.” It seems there is wisdom in this old saying…

As this article explains:

“In studies of what is called the hygiene hypothesis, researchers are concluding that organisms like the millions of bacteria, viruses and especially worms that enter the body along with “dirt” spur the development of a healthy immune system. Several continuing studies suggest that worms may help to redirect an immune system that has gone awry and resulted in autoimmune disorders, allergies and asthma.

These studies, along with epidemiological observations, seem to explain why immune system disorders like multiple sclerosis, Type 1 diabetes, inflammatory bowel disease, asthma and allergies have risen significantly in the United States and other developed countries.”

As I’ve written about before when I talked about our experience with the GAPS protocol, we’ve known about a link between gut health and mental health for a long time, and it turns out that certain soil based organisms play an important role here too:

Mary O’Brien, an oncologist at Royal Marsden Hospital in London, first stumbled upon these findings while inoculating lung cancer patients with a strain of M. vaccae (pronounced “emm vah-kay”) to see if their symptoms improved. She noticed that in addition to fewer cancer symptoms, patients also demonstrated an improvement in emotional health, vitality, and even cognitive function.

Heather (from Mommypotamus) talked about the benefits of these types of organisms for people with IBS or digestive disorders in this post:

Plus, in this double-blind, placebo controlled study researchers found that IBS patients who took a soil-based probiotic experienced a significant reduction in symptoms after two weeks. A follow-up study found that the patients were still experiencing these benefits one year after discontinuing the probiotic, presumably because the beneficial bacteria stays in the gut and continues to function.

Why Dirt is Important for Kids

So what does it mean for our kids? It means that all of our cleaning, disinfecting and sterilizing could be doing more harm than good at times.

Much to the chagrin of their mothers (and my husband!), babies have a natural desire to play in the dirt and put dirty objects in their mouth. Turns out, this could have an important immune developing purpose:

What a child is doing when he puts things in his mouth is allowing his immune response to explore his environment,” Mary Ruebush, a microbiology and immunology instructor, wrote in her  book, Why Dirt Is Good: “Not only does this allow for ‘practice’ of immune responses, which will be necessary for protection, but it also plays a critical role in teaching the immature immune response what is best ignored.

After a study found that kids who grew up on farms or with a dog in the house had fewer allergies, research started to explore the importance of the organisms found in these less-than-sanitized environments and how they impacted health.

“One leading researcher, Dr. Joel V. Weinstock, the director of gastroenterology and hepatology at Tufts Medical Center in Boston, said in an interview that the immune system at birth “is like an unprogrammed computer. It needs instruction.”

He said that public health measures like cleaning up contaminated water and food have saved the lives of countless children, but they “also eliminated exposure to many organisms that are probably good for us.”

“Children raised in an ultra clean environment,” he added, “are not being exposed to organisms that help them develop appropriate immune regulatory circuits.”

Studies he has conducted with Dr. David Elliott, a gastroenterologist and immunologist at the University of Iowa, indicate that intestinal worms, which have been all but eliminated in developed countries, are “likely to be the biggest player” in regulating the immune system to respond appropriately, Dr. Elliott said in an interview. He added that bacterial and viral infections seem to influence the immune system in the same way, but not as forcefully.”


“In the June 2012 issue, The Journal of Allergy and Clinical Immunology published a study that demonstrated that Amish children who grew up on farms in northern Indiana had significantly lower rate of allergies than non-farm populations (5.2% for Indiana Amish populations, 11.3% for non-farm Swiss populations). This is called “the farm-effect” and has been documented in farm populations across North America and Europe, with a 50% reduction in allergic occurrence in farm children.

In the United States, the third National Health and Nutrition Examination Survey found 54.3% of the study population to have evidence of allergic sensitization to at least one thing.

A recent study shows that the Amish have a lower incidence of asthma and allergies than non-farm populations.

Add to that the results of a study American Journal of Respiratory and Critical Care Medicine published in 2007 that shows the use of cleaning sprays 4 times a week caused an increase in asthma and you can start to see the problem. Sprays that were included in the increase in asthma were glass-cleaning, furniture and air freshening sprays.”

Why Dirt is Especially Important for Babies

The natural organisms in dirt serve an important purpose for people of all ages, but babies have a specific and additional need for interaction with dirt.

Breast milk lacks Iron and with important reason. Pathogens like E.Coli (which can cause severe digestive problems in newborns) needs Iron to thrive, as do other pathogens. These low iron levels can help protect newborns from these bacteria.

Around 6 months, a baby’s  need for Iron and other nutrients increases, but breast milk doesn’t increase its levels of these nutrients and with good reason. At this stage in life, babies spend more time on the ground. In the past, this meant they spent more time interacting with dirt, which is a good source of Iron and minerals like Zinc, magnesium, etc.

As Science of Mom explains:

  • “Most babies are born with enough iron stores to meet their needs for about the first 6 months of life [1].
  • Breast milk contains very little iron (~0.35 mg/liter). The Institute of Medicine recommends that infants 6-12 months old get 11 mg of iron per day [1]. By this age, most babies’ iron stores have been depleted, so this iron needs to come from complementary foods, in addition to breast milk or formula. If you try to meet your infant’s iron requirement on breast milk alone, she would have to consume between 4 and 13 liters of breast milk per day, depending on your baby’s efficiency of iron absorption from breast milk (estimates range from 15-50% absorption). Most exclusively breastfed babies don’t consume much more than 1 liter of milk per day.
  • Iron deficiency during infancy increases the risk of cognitive, motor, and behavioral deficits that may last into the teens, even with iron treatment. Specific deficits that have been identified include impaired motor development at 18 months [2], mental retardation at 10 years old [3], increased need to repeat a grade, and increased behavioral and attention problems [4]. When I hear parents say that they declined the test for anemia at their baby’s 9 or 12-month check-up, I have to assume that they don’t know how serious iron deficiency can be for their child’s future.”

So is breastmilk inadequate? Hardly…

This study shows that babies are capable of absorbing Iron from soil (which they are naturally in contact with at this age if playing on the ground). Other mammals have breast milk that is naturally low in Iron at the same developmental times and these mammals are also capable of absorbing Iron and other nutrients from the soil, indicating that there is a biological reason for this.

In the past, the umbilical cord also wasn’t clamped immediately after birth (and there is good reason to delay clamping it these days too) which allowed more of the umbilical cord blood (the baby’s blood) to flow in to the baby. This resulted in higher blood levels and higher Iron levels, which would also help baby maintain Iron levels for a longer time.

I also give liver as one of baby’s first foods to help with iron levels, but that is another post for another day.

How to Make Sure We Get Enough Dirt

Step 1: Go outside. Step 2: Eat some dirt…. Just kidding!

We don’t actually need to make an effort to consume dirt to get the benefits of soil based organisms and nutrients in soil, we just need to make an effort to come in contact with it and to have our babies and children come in contact with it.

I take the following steps to make sure we get the health benefits of dirt:

  • Encourage my kids (including crawling babies) to play outside barefoot in the dirt as long as I know it is an area that hasn’t been sprayed with chemicals or contaminated in some other way. I garden and walk outside barefoot (which has other benefits too).
  • At the recommendation of this post, I also let my babies have an outside play area with organic dirt once they are 3-4 months or old enough to sit up or crawl. Yes, they get dirty. Yes, they put it in their mouths (that is the point). Usually, this area is just a small kiddie pool or pot or organic dirt with some toys in it to encourage play.
  • I let my older kids help my in the garden, let them play in the dirt, make mud pies and otherwise get dirty. If they’ve been playing in clean dirt, I also let them eat outside without washing their hands so they can transfer small amounts of these soil based organisms to their digestive systems.
  • We also all consume probiotic rich foods and drinks like water kefir, homemade sauerkraut, kombucha, and other fermented foods to make sure we are exposed to a wide variety of naturally occurring beneficial bacteria.
  • I supplement with a Probiotics. I also sprinkle these on the foods I feed my little ones and even dump a capsule in to the play dirt. (Probiotics has been clinically studied, especially in patients with IBS or digestive problems)

Did you know that kids need dirt? Do you let yours get dirty? Do you have any contact with dirt yourself? Think I’m crazy? Share below!

Katie Wells Avatar

About Katie Wells

Katie Wells, CTNC, MCHC, Founder of Wellness Mama and Co-founder of Wellnesse, has a background in research, journalism, and nutrition. As a mom of six, she turned to research and took health into her own hands to find answers to her health problems. WellnessMama.com is the culmination of her thousands of hours of research and all posts are medically reviewed and verified by the Wellness Mama research team. Katie is also the author of the bestselling books The Wellness Mama Cookbook and The Wellness Mama 5-Step Lifestyle Detox.


50 responses to “Why Kids Need Dirt”

  1. Nat Avatar

    Katie, just wondering.. do you agree with the quote that states these worms are all but eradicated from developing countries. I have followed your stuff for over 6 years. I do miss your old blog when it was just you. Haha.. I just know for a fact you do not believe USA or AUSTRALIA (Where I am) is worm free… Parasite worm that is, isn’t this what your selected quote is suggesting

  2. Alexander Karalis Avatar
    Alexander Karalis

    Hi Katie, to my great happiness, my 3 year old son has contracted intestinal worms. The question is do I let his immune system take care of it or do I give him Mebendazole? The real question is if there is a benefit to have a prologued exposure to the parasites or the mere fact that he contracted them is enough?

    1. Jamie Larrison Avatar

      When someone gets the flu they can help their body’s natural defenses and support the immune system with things like elderberry syrup. I would imagine the same would be true for parasites and it would be something that would benefit from some kind of treatment. Ultimately it’s best to check with their healthcare provider when making a decision on parasite treatment in kids.

  3. Annie Avatar

    Vey nice post.i also wanted to be like this for my kids as I myself grew up in a village freely playing in dirt and soil.but now the only dirt for my kids is a small backyard of our townhouse.we have some strawberry and bluberries for kids sake..they do a lot of digging and everything over there and then come and graze on the fruits which kept open the dining table..I cannot supervise them to clean their hands as they play as often as they like..
    My problem is the worm..they are highly infected by worms ..they scratch their bottom most of the days..I feel like I should ban them playing outside..can I have your thoughts here…
    They only have occasional sweet intake..

  4. Meredith Avatar

    Did anyone ever find organic dirt on Amazon? We don’t have any organic farms nearby!

  5. Amy Avatar

    I live the the mountains of NC and grew up going barefoot all the time. I still do. My husband thinks I am crazy because I work in the garden barefoot. My grandkids are always outside in the woods, branch and dirt without shoes on.

  6. tracie Avatar

    I grew up on a farm and spent way too much time in the garden and around the barn to think there was anything weird about being covered in dirt (or worse). My sisters and I got a big dose of mud and probably some manure mixed in there too. : ) My husband is a city boy, and we live in a quiet, clean suburb. But I still make sure my kids (all five of them, between age 9 and 18 months) get plenty of dirt and plenty of barefoot time all summer long. My husband was horrified when our first was learning to walk and he realized I had no intention of buying shoes for him. The last straw was when he said something about only white trash going barefoot. At that point I was bound and determined to raise kids who think shoes are stupid and barefoot is fun. My husband used to argue and try to get them into shoes, but you’d be surprised how easy it easy to lose kids’ shoes in the summertime once school is out, so a lot of the time barefoot is the only option for our kids because we can’t find a pair of shoes anywhere. (Wink, wink — maybe hubby should have looked in the trash : ) After child 5 arrived, even my husband gave up, and he no longer says a word of complaint about his barefoot kids and their dirty feet. And if the kids are barefoot, Momma needs to be barefoot too so I can make sure I know what the kids are stepping on. : ) Momma knows best! Dirty children are happy, healthy children!!

  7. John Avatar

    Our son’s pediatrician recommended corrective shoes when he was six because he was a bit pigeon-toed. When we asked whether going barefoot wouldn’t be better for him than corrective shoes, she reluctantly said yes. And with some persistence, we finally got a note from her for his school, requesting that he go barefoot. We promptly donated all his shoes and socks to charity and let our son go barefoot 100% — school , church, shopping. Our son was delighted, and his pigeon-toeing was gone after a few months. The only problem was that he learned to hate wearing shoes. We managed to get one more year out the doctor’s note at school, but after age seven, they forced him to start wearing shoes again. He still went barefoot almost everywhere else until about age 12, when he decided shoes were cool.

    1. Susie Avatar

      John, great story about dealing with the shoe police at school. Our son has some sensory and attention issues, and his therapist likes for him to be barefoot as much as possible. His kindergarten was absolutely okay with him being barefoot, but when he started first grade, the school put their foot down (ha, ha). ADA to the rescue! His therapist wrote a plan for him that included him getting to go barefoot at school, and after a lot of arguing and a threatened lawsuit they finally gave in. We had to sign a liability release, but he hasn’t worn shoes at school now for two years! (We are in southern California.) And with no shoe police to bother us any more, we too got rid of ALL of his shoes except one pair of flip flops for “special” occasions. I don’t even know his shoe size. : ) Going barefoot must be contagious. All his friends try to go barefoot too as much as they can get away with, and a few more kids have gotten notes from our helpful barefoot-friendly therapist. I think she had to “stretch” a little bit to write notes for some of the other kids, but when we pointed out that our kid might be made fun off if he was the only one, she did not take too much persuading to help us get some barefoot friends for him at his school.

      1. Heather Avatar

        Love this! I am a teacher and it makes me smile when I hear these kinds of stories. My principal fussed at me for going barefoot. She didn’t now what to say when she saw me in the hall with 18 little barefoot 2nd graders ??

  8. Lindsay Avatar

    What brands of organic dirt do you recommend? Apartment dweller here and I’m concerned about getting a bag labeled organic but full of pesticides! Thanks!

    1. Chelsea Kissiah Avatar
      Chelsea Kissiah

      Is dirt the same as potting soil? Could you buy a bag of organic potting soil And toss it around your yard
      For kids to walk barefoot in? Or is that not the same thing? I read a post where you said something about a rare disease you get from messing in potting soil? Or is that just if you make Your own?

  9. Holly Shell Avatar
    Holly Shell

    Hi see more moms are asking same thing I’m wondering…where do u get the organic dirt good for kids play?! Thanks 🙂

    1. Katie - Wellness Mama Avatar

      The best option I found was to find a local farmer who had owned his land for a long time and practiced good farming practices and permaculture and didn’t spray. I bought some dirt from him.

  10. Amy Avatar

    This was a great read, thank you. Unwittingly I’ve done exactly what you outlined with my own children…not because I knew it to be healthy but just because that is how I grew up. (Imagine my delight to find that going barefoot, something I never stopped as I grew up, had wonderful health benefits!) My first born struggled with mild asthma like symptoms a few times a year which I partly attribute to mold in our apartment. When he was 5 we moved out to the country and built a house (so no more mold) along with running around for hours in the sunshine and dirt and fresh air (not to mention playing in the barn) and he gradually had fewer episodes to where it’s hardly an issue now. Wish I could post a picture of my dirty little children 🙂

  11. Yung Avatar

    would the organic soil, or even regular soil help a much older kid who has allergies/asthma most of his life and get sick much more than a regular kid?
    He is going to be 10 year old.

  12. Marianela Avatar

    I loved reading your article and I absolutely agree to all the points =) Kids benefit tremendously with the time spent playing in the garden and dirt. Our germaphobic, hyper hygienic society has actually placed us and our kids in a weaker state. It not only boosts their immune system but it also lets them connect with life on the most fundamental level.

  13. Tannis Avatar

    I’m not sure if you know the answer to this, but I know soil is one place that young babies can get botulism. In the spring when we are out more I want to let her get dirty for sure, but right now we live in an appartment and would love to get some organic soil for her to play it is 7 months passed that stage they should be more wary of the honey and soil bacteria ? I’m not going to feed honey until after a year but outing her in soil daily would be great except that part I wonder? Ahh first time mom worries! Who knew, as I love getting in the dirt outside but now worry more than I thought! And for the inside soil… Could I just ask and organic farmer for some or should it not be fertilized. Thanks!

  14. Joy Avatar

    All my nurseries in the area sell organic dirt but it has small wooden bits and splinters in it. I live in a large city and all 8 nurseries don’t sell anything without tree compost in it.

    Help! Is there a product on Amazon I can buy for my 9 month old, like a small amount of organic dirt? His iron levels are low because of being purely breastfed up to this point.

  15. Stefanie McCormick Avatar
    Stefanie McCormick

    Such a great article!!! I grew up in the country and I loved it!!! Our bodies are nature,so makes Alot of sense to get out in nature,as a mother to boys I never minded them getting dirty cuz I played in the dirt as a child…..thankfully they are healthy happy boys,I’m sharing this with my sister whom thinks that bleaching everything is beneficial for her and her families health!!

  16. Mary O Avatar

    I was wondering if you will be posting any recipe ideas for babies? Mine is almost 6 months and would like to make my own food instead of canned. Thanks for all you do!!

  17. Cindy Avatar

    I love this! We have always allowed our kids to run around barefoot outside. We barely ever wear shoes when it’s warm enough so I’m glad to hear there’s some scientific benefit to it!

  18. Dias Avatar

    I really like this theory and believe it now!! I have 2 kids 5 and 3 years , they are always sick unfortunately !! And I’m tired of this! I’m obsessed with cleaning and clean environment !! This was my mistake , I tried to protect them but actually I did the oppisite !! I don’t know what to do now after this time! I really need an advice if I can correct the situation and what I did 🙁
    What may help them now to make a better body better immune ??

Leave a Reply

Your email address will not be published. Required fields are marked *