I recently enjoyed a farm-to-table meal in the Malibu hills. We nibbled garden-fresh veggies and berries straight from the bush. After all, what’s a bit of dirt?
A lot, apparently. A hypothesis suggests that microbes that co-evolved with us are our ‘old friends’; they protect against a wide spectrum of immune-related disorders. Some of these are present in soil and can be inhaled when out in nature.
This might be why spending childhood on a farm is good for our lifelong health. Getting licked by the family dog, having siblings, and eating vegetables are also health-protective. If the veggies are organic—fertilized with manure and compost instead of simple ammonium nitrate—it’s even better.
Why? Each of these up our microbial diversity.
Exposure to animals, soil, and environmental microbes clearly impacts the gut microbiome: If the outside world has rich biodiversity, the internal environment will likely reflect greater diversity too.
It wasn’t surprising that my dinner mates weren’t germaphobes. Seasoned health writers, we have been ‘exposed’ to the original ‘hygiene hypothesis’ for decades: we know exposure to some microbes is healthy.
Turns out, exposure to more may be even better.
The human microbiome—in other words, the combination of all the bacteria, archaea, viruses, fungi and worms and other eukaryotes that inhabit the body—are more protective and adaptive when they are diverse.
Diversity and balance in our microbiomes are easier to achieve when our diet and the ecosystem we inhabit are balanced and diverse too. Ecological health is healthy.
Although ‘modern’ processed diets play a role in our dwindling gut diversity, it is important to acknowledge that moving away, often literally, from natural environments affects us in detrimental ways.
Pediatric gastroenterologist Dr. Eric Benchimol states that children living in rural households experience a protective effect against IBD (irritable bowel diseases like Crohn’s and colitis). The effect is apparent if they live there at 10 years old, but even stronger if they spent their first 5 years there.
Conversely, living in airtight, highly germ-free, concrete environments is a risk factor for developing certain diseases. I take a personal interest in this as I was born in a high-rise and live in one now.
We now know that urbanized living may create an increase in cases of fevers and allergies, as well as IBD and autoimmune diseases like type 1 diabetes and multiple sclerosis.
These diseases are highest in highly urbanized and industrialized countries like the US and Canada. We also eat a diet too low in fresh plant foods and too high in emulsifiers. As a result, a few bacterial species dominate. Our guts are very different from the diverse microbiomes of people living in less developed places.
Now, no one is suggesting that we were better off before sanitation. But extremes in anything, even hygiene, suggest a looming pendulum swing.
Lifestyle factors that create less healthy, less diverse microbiomes include many that come with industrialization:
- antibiotic use, ingestion, or exposure
- foods that lack fiber or use synthetic emulsifiers
- stress, artificial lights, and lifestyles that disrupt circadian rhythms
- pollution, medications, and toxicants
- lack of exposure to green space, animals, and soil
Yet rural communities around the world are shrinking, as urban areas and “grey spaces” grow. Most people get little time in lush outdoor environments. In Ontario, where Dr. Benchimol practices, rural populations are declining primarily from an exodus of youth to universities and jobs. As they go, so do some of their microbes.
Given the relationship between eco biodiversity, dietary diversity, and microbiome diversity, what can we do?
Rural living or even getting a dog are not options in my immediate future. Other things we can do include:
Shop the farmer’s market and the produce store.
Diversity is improved with a diet rich in organically grown vegetables and fruit. Aim for 30+ varieties of plants per week.
Sleep in a dark room with the window open and walk outside daily.
When we open the windows, get outdoors, tend a patio garden, and play touch sports, we may increase the diversity of our microbiomes. We may even alter the gut microbiome to be protective against asthma and respiratory viruses.
Be mindful with medication and avoid antibacterial toothpaste, detergents, soaps, and sprays.
What we put in, on, and around on bodies matters. Antibacterial products can negatively impact health so avoid them when you can.
By this, I don’t mean ultra high heat sterilized, of course. I mean it the way Tosca Reno intended: avoid junk. In particular, avoid antibiotics, polysorbate-80, and carboxymethylcellulose (synthetic emulsifiers) in your food. Enough said!
Of course, if you can get a dog, go for it. The more affectionate, the better! If you can’t get a dog, hug people. There is no scientific study for that yet, but I think there should be.