The power of dirt: How exposure to soil and farm animals can benefit your gut microbiome



In our modern world, we’re often taught to fear germs and to avoid exposure to dirt. However, research shows that this mindset may be misguided when it comes to gut health.

In fact, exposure to a diverse range of microorganisms, including those found in soil and on farm animals, can actually have significant benefits on your gut microbiome.

Soil: Why playing in the dirt is good for you

Soil has an essential role in human life and on the human microbiome [1].

Water we drink runs through it. Plants we eat grow in it. Houses, playgrounds, and daycares we inhabit are built on it. Soil is a microbe dense environment with a wide variety of species present [2].

If you’re wondering why playing in the dirt is good for you, let’s look at the impact of living in the city. 

In individuals living in urban environments, the microbial gut diversity is lower compared to individuals living in rural environments [3], [4]. This is thought to be linked to the decreased interaction with soil, as well as other environmental factors. Exposure to dirt in childhood may promote immunity.

Similarly, individuals with yards that have a greater amount of different plant varieties have been shown to have a different gut microbiome variety. They have been found to have reduced levels of Bacteroidetes and increased levels of Firmicutes, which has been shown to lower the risk for obesity [5].

Even where your children play in daycare can affect their microbiomes. 

One study found that playing in nature-oriented daycare centers had several health benefits, such as:

  • Improved immune systems
  • Diverse skin microbiomes
  • Diverse gut microbiomes

In the study, children had contact with nature five times a week for a month. While outdoors, children’s would do guided activities in nature, including:

  • Planting plants in planter boxes
  • Crafting natural materials
  • Playing games
  • Peat blocks for climbing and digging [6]

Playing in the dirt is not only fun, but also good for you and your baby's gut microbiome. 

But, not all dirt is the same. Some dirt and soil can be contaminated with lead. High lead exposure to your children can potentially cause toxicity [7]. It's best to avoid having your baby play in lead-contaminated soil. This can be in places such as:

  • Urban areas
  • Places with artificial turf
  • Industrial parks
  • Homes built before 1978

Farm: Does growing up on a farm help your immune system?

Old McDonald had a farm, with a cow, pig, duck—and also microbes!

Children living among farm animals are inhaling and ingesting bacteria. Research has shown that exposing babies to farming agriculture and farm animals can also influence their microbiome.

For example, one study found that two-month old babies who lived in a farm had higher levels of Bifidobacterium infantis in their gut, compared to babies from urban/suburban settings [8].  Another study found that living on a farm increased the levels of Firmicutes in babies [9], which can have positive health benefits later in life.

Put simply, growing up on a farm helps your baby immune system. 

Living around farm animals has been shown to potentially reduce the risk of allergies and asthma [10]–[13]. This can be seen with children of full-time and part-time farmers being at a lower risk for pollen allergies and atopic sensitization [14], [15]. Atopic sensitization includes things like allergic eczema and asthma.

Even moms exposed to farm animals, grass, and hay, have babies with lower seasonal allergy marks [16]–[18].

When we look a little closer at their microbiome, we find that children with asthma at 4 years old have been shown to have modified gut microbiome compositions. They showed lower levels of beneficial bacteria, including:

  • Bifidobacterium
  • Akkermansia
  • Faecalibacterium [19]

Children with asthma instead had a higher amount of fungi, including:

  • Candida
  • Rhodotorula [19]

From walking on dirt to playing with animals, beneficial microbes are introduced to your child's microbiome. This can provide several health benefits, such as:


  • Modulation of the immune system
  • Allergy benefits
  • Lower risk of asthma

Even more so, playing outside can have beneficial effects beyond the microbiome. Children exposed to green spaces have been associated with beneficial effects on brain development and cognitive function [20]. Even exposure to nature during childhood has been associated with better mental wellness in adulthood [21]

Without a doubt the outdoors is a great way for you and your child to have fun, but also introduce the world of microbes.


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[9] S. Dhakal et al., “Amish (Rural) vs. non-Amish (Urban) Infant Fecal Microbiotas Are Highly Diverse and Their Transplantation Lead to Differences in Mucosal Immune Maturation in a Humanized Germfree Piglet Model,” Front. Immunol., vol. 10, p. 1509, 2019, doi: 10.3389/fimmu.2019.01509.

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[15] J. Riedler, W. Eder, G. Oberfeld, and M. Schreuer, “Austrian children living on a farm have less hay fever, asthma and allergic sensitization,” Clin. Exp. Allergy J. Br. Soc. Allergy Clin. Immunol., vol. 30, no. 2, pp. 194–200, Feb. 2000, doi: 10.1046/j.1365-2222.2000.00799.x.

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[21] M. Preuß et al., “Low Childhood Nature Exposure is Associated with Worse Mental Health in Adulthood,” Int. J. Environ. Res. Public. Health, vol. 16, no. 10, p. E1809, May 2019, doi: 10.3390/ijerph16101809.