In the garden, the soil at our feet is teeming with life.
Beyond worms and arthropods which can be seen with the naked eye, microbia of all sorts play a vital role in the healthy environment of the ground where our food and plant medicine grow. Similarly, the human body harbors up to ten times as many microbial cells as human cells. What are these microbes and what are they doing? What do they tell us about ourselves? Just as our human genome records traces of who we are and the conditions we have adapted to during evolutionary history, our microbial genomes may record traces of what we have eaten, where we have lived, and who we have been in contact with.
My daughter is the one who drew my attention to this subject. As a young toddler she consumed more dirt on our organic farm than I thought humanly possible.
At first I tried to dissuade her. When nothing dire happened to her, and when she stubbornly persisted I began to wonder if she wasn’t craving something she needed. Adopted at birth, she was never breastfed, except once. I made her a formula using raw goat’s milk as a base, but the formula was low in iron, something that bottle fed babies often lack.
Our soil at that time was very high in iron so I assumed that she was eating the dirt because she craved iron. But then I began to notice that she never got sick. She was the healthiest baby and toddler I had ever seen. With her first two teeth she had a low-grade fever for a few hours and that was it for her entire babyhood...until she weaned off her formula and dirt.
That’s when I began to wonder if she innately knew something I didn’t.
I decided to write a book about why eating dirt was such a good thing. It didn’t take me long, when I started researching, to stumble on the then-exploding science of the microbiome. I never wrote that book; I didn’t need to since a pile of books on the topic were proliferating faster than I could sharpen my pencil. However, I did learn a lot on the topic, the most important lesson being how key our diets are to the health of the magical world of bugs in our gut.
Imagine holding a human brain in your hands, about three pounds. Now imagine instead of a mass of grey matter in your hands you are holding a squirming pile of bacteria. That is the amount of microbes found in a human gut.
This amounts to trillions of microbes which hang out in and on us, and in and on the soil at our feet. Scientists have learned that these bacteria in the gut play a vital role in digestion, in the production of certain nutrients, the development of our immune systems, in setting our metabolism making us thin or fat, in inflammatory and auto-immune disorders and even in what we think and feel. Multiple studies have demonstrated that people with a rich diversity of bacteria are healthier and better equipped to thwart inflammatory conditions such as autoimmune disease, cardiovascular disease and arthritis. Overweight and obese people are prone to lower bacterial diversity and so are vulnerable to insulin resistance, cardiovascular disease and overall inflammation compared to thin people.
So how do we create an environment that feeds diversity and sustains a wide diversity of microbes?
Your first guess might be to eat more fermented foods, such as sauerkraut and yogurt - maybe not at the same time! While the bacteria that thrive in these foods do have an important influence on the the activity of our established gut microbiomes, there is another food that plays a more significant role: fiber-rich vegetables. Gut bacteria love carbohydrates, but because you digest most of them before they hit the colon where most of our gut bugs hang out, they have evolved to survive on the carbohydrates present in dietary fiber that we cannot digest ourselves. Increasing our dietary sources of this "bug fuel” will provide for a thriving and more diverse bacterial population of bacteria in our guts and so assist weight loss, lower inflammation, decrease chronic diseases.
Vegetables rich in soluble fiber are key. If your gut bugs don’t get enough fiber, they turn to an alternate source of carbohydrate: the mucus lining of you large intestine - yum!
Eating a wide diversity of vegetable is the answer: asparagus, leek, tomato, radish, as well as countless greens, roots and other vegetables and berries.
The most encouraging and amazing thing about the microbiome is its incredible capacity for rapid transformation. By changing what food is arriving in your gut, you can transform the population in as little as 72 hours. This changeability is why many scientists see the bacteria of the gut as potentially one of our most powerful tools for transforming health. The key to success here is consistently eating the food that nourishes and sustains health-promoting bacteria over time. While positive change can be made quickly, the health benefits won’t be realized unless this change is supported for the long haul. As quickly as diversity can improve, if we fall back into old habits, the former inflammatory-promoting bugs will return just as quickly.
The short answer? Support a local farm and enjoy the variety of vegetables each season offers. Challenge yourself to include vegetables and/or berries in every meal. Use an online fiber counter and see how many grams of fiber you consume daily. Most Americans eat less than 15 grams/day, while our hunter-gatherer ancestors ate over 80 grams. Be forewarned that jumping from 15 grams of fiber to 80 grams is a recipe for gas and bloat like you’ve never experienced. A gentler approach would be to gradually increase your fiber over time. Adding a soluble fiber powder such as inulin is an easy way to boost a source of fiber that our gut bugs thrive on.
Is it easy for you to eat vegetables? Do you have a favorite way to sneak more veggies into your diet? I’m always looking for tips to share!