The intersections between soil health and human health are myriad and, from a human health perspective, may best be viewed through a lens of what soils "do for us" vs. what soils "do to us." - Dr. Eric Brevin
For most of history we have focused on soil as causing disease. And while there are certain naturally occurring substances in soil that do cause disease, such as arsenic or parasites from degraded soil, soil microbes actually determine the nutritional value of our food.
The health of our mother’s gut biome influences our health in vitro. From birth we are dependent on microbes, in the soil, our food, and in our gut for optimum health. The connection between a diverse exterior microbial environment and our gut diversity is now an interest of human health researchers.
Soil Microbes And "The Farm Effect"
Dr. Daphne Miller has written about "the farm effect". Kids who grow up on a farm where no chemicals are used have a much more diverse gut microbiota. They are also less likely to have allergies, asthma, or autoimmune diseases than kids who grow up in an urban apartment or conventional farm.
The farm effect concept is simple. Kids on farms are outside making mud pies, handling livestock, chasing the dogs and cats, exposed to barnyard dust, and playing in the woods. They encounter billions of microbes on a daily basis, which allows their bodies to develop immunity to an extremely large body of air and soil-borne microorganisms.
Kids who grow up in urban areas, who have no pets and spend most of their time indoors, encounter a relatively small diversity of microbes which impacts the diversity of their gut microbiomes. Their bodies never have the chance to build up immunities. And that’s critical.
The First Three Years Of Life And The Human Gut Microbiome
As adults we may experience health problems such as food allergies, Crohn’s disease, or inflammatory bowel disease, so we decide to change our diets to include more nutritious food. Whenever we change the types of foods we’re eating, there is a period when we feel like we’re missing something, or we feel hungry. Our bodies are telling us we aren’t feeding the microbes that live in our gut.
Dr. Emeran Mayer, a gastroenterologist who is also interested in soil health, has said that after three years of age a child’s gut microbiome is almost the same as an adult. The first three years of a child's life are critical because multiple factors are at play in forming the initial gut microbiome. Those factors include genetics, but more important are exposure to many different microbes in the form of food and environment. During the pre-natal period the gut of the fetus is affected by the mother’s diet, stress level, overall health, and any medications. A healthy infant gut microbiome plays a pivotal role in a person’s health.
If, as a child, we did not acquire the gut microbes for a healthy life we can opt to change our food and lifestyle choices. To create a healthier microbial community in the human gut requires a commitment to a long-term lifestyle change. If you’ve spent a lifetime eating an unhealthy diet, your gut microbiome will not change overnight. Talk about lifestyle change…
A young couple I know were expecting their first child. They grew most of their own food, did a great deal of fermentation, and were vegan. They wanted their child to be as healthy as possible so they made a plan for her life. She was born at home with a midwife and immediately laid against her mother’s bare skin. Of course, she was breast fed. After weaning she was fed only vegetables her parents had grown themselves or knew the source was chemical-free. Baby food made from scratch with no additives. A sweet treat was a carrot.
This may sound extreme but, to this day, fruit is that woman’s “go-to” sweet and she is never sick. Her immune system is strengthened by her own gut microbial life.
Healthy Food Leads To Healthy People
Very few of us grew up like my friends’ daughter. Some of us grew up in rural areas where we got some “farm effect” through close contact with soil bacteria by playing in the yard. But many of us grew up in urban areas with little, if any, contact with soil microorganisms.
At some point in our lives, we may discover we are at significant risk of the debilitating effects of chronic diseases. Or we feel stressed and don’t know why. A new study by a research team led by Dr. Christopher Lowry at Colorado University at Boulder, "…has discovered that a specific strain of bacteria found in soil can help protect people against stress." Playing in the dirt has a positive impact on our mood!
So, we change our lifestyles to include a more diverse array of fruits and vegetables and pay attention to the quality and sources of our food supply. Maybe we even start growing some of our own food. Our gut microbiome may even encounter some “old friends,” microbes from foods from our early years that we haven’t eaten in a while.
Farming Practices And A Healthy Soil Microbiome
To maintain control over our food quality we need to start asking questions. This is easier at the farmers market than the grocery store, but a lot of information is on a label. Food production in the United States is regulated, at least regarding food safety. We may know what preservatives are in a processed food but unless it’s organic we won’t know the agricultural practices or if soil quality played any, not to mention a major, role in plant growth.
Plants wouldn’t even be present without the existence of microbes. The health of all life is dependent on the symbiotic relationship between microbes and plants. The more biodiverse the soil the more essential nutrients are available to plants, and therefore to us.
Farming practices that increase soil biodiversity include no-till, cover crops, crop rotation, attention to water quality if irrigating, among others. Question your grower about his farm practices so you can make an informed decision about the nutritional quality of their food production.
Microbes cycle nutrients in the soil which makes those nutrients plant available. Every time we sit down to a nutritionally dense meal, we need to remember the major role soil microbes play in our health. When we take the kitchen scraps out to the compost bin we’re contributing to the circle of nutrient cycling of microbes and plant matter.
Want to learn more about the fascinating world of soil microbes and human health? Check out our blog "How Soil Health Influences Our Health".
