The Gut
Soil Connection
This article is part of Issue #14
From live cultures to permaculture, soil health and human gut health are intrinsically and ancestrally linked.
The inner working of our digestive system is a hot topic now - discussed over dinner and on dates. Our alimentary canal is even used to market products in mainstream supermarkets. British supermarket Waitrose has a range of products called Gut Health and yoghurt brand Activia is also using the phrase ‘gut health’ too. Sadly, one of the main reasons there is so much hype is because our inner ecosystems are suffering.
The Human Microbiome Project was launched in 2007 by the National Institutes of Health in the US, alongside many other studies in labs around the world, to help us understand how the bacterium in our guts affects our health - especially in a period where chronic disease had reached a state of alarm. One of the major insights to surface from the project is the link between gut health and soil health.
The human microbiome and the soil microbiome, and indeed the plant microbiome, share an ancient ancestry. The human body is estimated to contain around 39 trillion cells (although most of these are red blood cells which are not strictly cells because they lack a nucleus). Latest research suggests the human body contains between 10 and 100 trillion microbial cells. Soil on the other hand does not have any boundaries so the number of microbes is practically limitless. To create a healthy, flourishing microbiome, we must nurture the land that feeds our food.
In the period between 1996 and 2007, cancer rates in the United States saw a major spike. Zach Bush MD, a physician and thought leader on the microbiome is linking the rise in cancer rates directly to the use of chemicals in farming, namely glyphosate. “To see an entire population, respond in a single decade to a sudden explosion of cancer suggests we did something similar to Chernobyl. We did some massive environmental injury that led to this explosive rise in cancer,” he says in his documentary Farmer’s Footprint, where he makes a distinctive link between the use of glyphosate (a herbicide used in farming) to the sudden rise in cancer as well as chronic diseases.
Glyphosate is used to kill weeds, especially grasses that compete with crops. It was discovered by Monsanto Company chemist John E. Franz in 1970 and was brought to market for agricultural use in 1974 under the trade name Roundup. Farmers quickly adopted glyphosate for agricultural weed contracts, especially after Monsanto introduced glyphosate-resistant Roundup Ready crops, enabling farmers to kill weeds without killing their crops. In 2007, glyphosate was the most used herbicide in the US. From the late 70s to 2016, there was a 100-fold increase in the frequency and volume of application of glyphosate-based herbicides worldwide.
“Glyphosate became a commodity in farming in 1996. Before that it was used as a weed killer by homeowners and farmers alike and it had to be used sparingly because it kills everything it touches,” Bush explains, likening chemicals used in farming to antibiotics, which also deplete all life. I can use his findings as a metaphor for my own system. I did a gut health test 12 years ago to discover my microbiome resembled a barren landscape bereft of life. My score out of ten was zero. Even though I ate an organic, plant-focussed diet, the fertile ground I was born with was destroyed by antibiotics during my American childhood.
Shann Jones, a co-founder of Chuckling Goat, which produces award-winning kefirs in Wales, compares our gut microbiomes to a rainforest and likens antibiotics to bulldozers that rip up the delicate and complex ecosystem, destroying all the trees as it were, uprooting diversity and limiting growth - if not killing all life. Jones saw the link between soil and gut health: “I first learned about the microbiome by looking at my compost heap. The process of microbes and microbial life breaking down waste and turning it into energy is as close to magic as you can get. Every ecosystem is the same and the rules for looking after it are exactly the same: feed it, love it, don’t poison it."
The human microbiome and the soil microbiome, and indeed the plant microbiome, share an ancient ancestry. To create a healthy, flourishing microbiome, we must nurture the land that feeds our food.
“We have a very point-and-shoot mentality and approach to health on all levels be it gut health or soil health. You can’t just target one thing or microbes will come in like weeds and take over,” Jones says. “I try to get my clients to look at their microbiome like a garden, it needs tending and when you look after it, it responds.”
I had a lot of antibiotics when I was a child, even though I don’t really remember being sick - they felt like a knee-jerk remedy, sometimes for even the slightest sniffle. It’s hard to grow plants in dead soil so I had to restore the playing field, creating a clean slate by stripping my diet right back to basics. After a six-week reset, I started to ‘plant new trees’ by introducing probiotic-rich foods such as kefir and sauerkraut.
After 12 years of rooting a lot of fermented food ‘trees’ which I nourished with fibre-rich, prebiotic foods like oats, apples, sunflower seeds and dandelion leaves, I got a dramatically improved Gut Health ‘report card’: Microbiome diversity score: 9 out of 10. Your microbiome diversity is high.
Diversity indicates the approximate number of bacterial species that live in a person’s gut. Each type has its own functions that are often complementary. A diverse microbiome can perform a broader range of tasks that regulate and compensate, making the whole system more stable.”
In 1996 Jody Scheckter - a former Formula One driver - set up Laverstoke Park Farm, a biodynamic farm in Hampshire that has since been a leader in the organic food sector, establishing the only licensed Soil Foodweb Laboratory in Europe. The lab studies the activity of different groups of beneficial microorganisms in the soil and you can see the microbiological contrasts of living organic soil compared to a conventionally farmed soil fed with chemical inputs. Through the narrow lens in the Laverstoke soil lab, conventional soil looked like a blank slide - a dark hole of nothingness. But the organic soil was like a live abstract painting of dancing wiggles and moving dots.
Geologist Eddie Bailey gave me a similar insight after coming on one of my River Cottage seasonal fermentation courses. Albeit his biological slide show was a little different. He sent me a picture of the live cultures in my kombucha SCOBY - a jelly-like symbiotic culture of bacteria and yeast. Adding a SCOBY to tea mixed with sugar is similar to adding a sourdough starter to flour and water. The bacteria in the culture feeds off the natural sugars to create carbon dioxide - giving fizz to the drink and bubbles to rise the bread. Under a microscope, a healthy culture should look like healthy soil and when you consume foods teaming with life, their vibrant energy will take root in you.
Alongside geology, Bailey is a Soil Food Web specialist at RhizoPhyllia, where he teaches gardeners and growers how to nurture healthy soils so they can grow more nutrient-dense and disease resistant plants. “A healthy plant relies fundamentally on a complete and fully functioning soil food web,” says Bailey. “The microorganisms act like a bridge between the soil and the plant. In the same way, a healthy human relies fundamentally on a healthy gut microbiome that delivers the metabolites you need. The soil microbiome and the gut microbiome must be cared for and fed properly if they are to do the job nature intended.”
Diversity is key. “A typical family in Britain will eat about 30 different types of crops throughout the year,” notes Rakesh Rootsman Rak who teaches permaculture design courses in London and across the globe. Permaculture is an approach to land management that echoes natural ecosystems. “The modern diet, particularly in the west, is so narrow. It’s so limited and then we’re surprised when there’s disease. There’s not this balance in your ecosystem because what you’re putting into your ecosystem is so monoculture.” While there are an estimated 10,000-50,000 edible plant species, only 150 are currently cropped. What’s more, it’s estimated that these agricultural crops have lost three-quarters of their genetic diversity through industrial farming since the 1900s, according to the Seed Co-Operative, the UK’s community-owned organic seed company.
Forager Monica Wilde proved the benefits of a complex diet after making a quiet but radical pledge to live only off free, foraged food for an entire year. Her award-winning book The Wilderness Cure documents her consumption of 300 different plant species, 87 different fungi, 20 varieties of algae as well as wild meat, fish and eggs. This extensive range of wild foods comes from perennial species tapping deeper into the nutrients and minerals in the soil, especially in comparison to annual crops which have shallow roots and faster growing periods. The impact of this diet on her health is what took her by surprise. She felt more energetic, so much so that she decided to get a microbiome test. Monica mused, “The report showed that my microbes were going up and down like they were having a party. My friend, Matt Rooney, a type 2 diabetic who joined me on this unusual diet, regained pre-diabetic blood status in just nine weeks.”
To gather more scientific research around the impacts of wild food on the gut microbiome, Wilde and Rooney have launched the citizen science study The Wildbiome Project, with support from Tim Spector - a professor of genetics and author of books including The Diet Myth. Spector co-founded ZOE, a nutrition science study and programme, which will provide tests to measure the results. “26 of us will eat only wild food for three months (Cohort A) or just one month (Cohort B). They’ll be monitored against a reference control of 26 people eating normal shop-bought food.” Illustrating our lack of engagement with environment, Wilde makes an astounding observation: “Most people get their nature from the television.”
In Losing Eden: Why our Minds Need the Wild, Lucy Jones writes about having a garden for the first time at the age of 32 after moving from London to rural England. “I quickly noticed two things. First, my baby daughter seems to like eating soil. Second, during and after time spent in the allotment or garden, I felt happy, upbeat, less stressed and generally more positive.” Initially, she thought it was just an anecdotal effect of increased exercise and fresh air, but then she discovered the biological connection. Jones’ anecdotal experience is backed up by science. Neuroscientist Dr Christopher Lowry at Bristol University authored a paper making a direct link between ‘friendly’ bacteria (Mycobacterium vaccae, specifically) - normally found in the soil - and altered behaviour in a trial with mice, having a similar effect produced by antidepressant drugs. “These studies leave us wondering if we shouldn’t all be spending more time playing in the dirt,” he said.
As far back as the 1760s, soil was thought to have a curative effect on mental and physical health, with geophagia (the act of eating soil) documented by authors ranging from Roman physicians to 18th century explorers . Geophagia is widespread among pregnant and breast-feeding women in western Kenya, suggests Daphne Lambert, nutritionist and author of Living Food: A Feast for Soil and Soul, and “In Siberia they consume tiny balls of soil to stimulate the immune system.”
Emeran Mayer, a gastroenterologist at the David Geffen School of Medicine at UCLA, involved with the Human Microbiome Project, notes: “Our health is not only predicated on the activity of the microbes in our guts, but on the microbes we ingest both directly (from purposeful geophagy, or accidental dirt ingestion) and indirectly (in the form of plant crops) from the soil.”
“People are always shocked when I eat veg from my garden without washing it first. I know what’s in my soil,” says Lambert. The word human comes from the word humus. To be human literally means to ‘be of the soil’. When Lambert launched her book, the first thing on the menu was a spoonful of soil from her garden. “The problem we have now,” says Lambert, “is we live in a Detol era. Soil is an important element in strengthening childhood immunity, but children don’t have enough contact with healthy soil.”
In 1989, David Strachan, Professor of Epidemiology at the University of London, proposed the idea of the hygiene hypothesis, proposing that lower incidence of infection in early childhood could be an explanation for the rise in allergic diseases such as asthma and hay fever during the 20th century.
“The sterility of our environment is not good for our immune systems. Our bodies need to be challenged,” says Dr Adrian Izzard, who set up Wild Country Organics after completing a PhD in human nutrition. In the west, our lack of engagement with the earth has been linked to the rise in childhood allergies and autoimmune disorders. Izzard moved into farming after his father was diagnosed with Parkinson’s disease in the late 1990s. Harking back to Zach Bush’s links to the impacts of chemicals in farming on human health, Izzard believed his father’s illness was connected to the use of organophosphate pesticides used in horticulture in the 70s and 80s.
A diverse microbiome can perform a broader range of tasks that regulate and compensate, making the whole system more stable.
A day spent on one of Eddie Bailey’s Rhizophyllia workshops helps illustrate the full picture. Beyond seeing the life in healthy soil and the bacteria dancing about on ‘live’ fermented foods, Bailey also shows how to measure the nutritional density of foods, focussing on a comparison of vegetables grown in his garden to ones purchased from a local supermarket. He uses a Brix scale, which specifically measures the sugars in a plant but on a deeper level offers a richer nutritional insight.
The Brix scale ranges from 0-32°. Fruits and vegetables generally range between 12-18°. A Brix level of 4 or 5° would indicate that the plant is suffering from boron deficiency. Boron deficiency affects the vegetative and reproductive growth of plants resulting in an inhibition of cell expansion, death of meristem and reduced fertility. A Brix level of 18° indicates a very healthy and well-fed plant.
On a summer course, Bailey’s sweetcorn scored the optimum - a Brix level of 18°. The supermarket equivalent measured 7.5°. “I cooked the supermarket cob and happily munched my way through it, disposed the cob and went on with life. When we cooked and ate ours the next day, I couldn’t eat more than half of it because it was so sweet and full of phytonutrients. My body, or more to the point, the bacteria in my gut, they were telling me ‘That’s all the zinc you need, that’s all the copper you need, that’s all the potassium… Cobalt tick. Nickel tick… Right Ed, you don’t need anymore’. But I thought I’m only halfway through it. That happened because it is so nutrient dense. The more processed foods are depleted in nutrients, the microbiome remains hungry because although it may have all the carbohydrates it needs, it’s missing the nutrients needed to support the immune system and those excess carbohydrates (calories) are put into fat stores.”
Reassuringly, the solution to a healthy microbiome is right under our feet and both our gut microbiome and the soil microbiome respond quickly to change, the benefits are often more delicious as Bailey saw with his intensely-flavoured sweetcorn.
This article is part of Issue #14
Landscape Kinship Connection
Themes in this issue include a delve into the intricacies of identity, heritage, and connection to the environment; Indigenous worldviews and myth …
Explore Issue #14