By David Clements
In my last column, Living with wildlife, I was inferring that with wildlife all around us, we have to learn to live with it. But there is also wildlife within.
“You are an ecosystem,” proclaimed Norm Wirzba, a guest speaker to my ecology class earlier this year.
Wirzba is at Duke Divinity School in North Carolina where he studies “the intersections of theology, philosophy, ecology, and agrarian and environmental studies.” And bacteria….
Just as we often take an alarmist view of wildlife that impinges on our lives, talk of bacteria tends to make us fearful.
Given the latest figures on the ecosystem within, the microbiome, this is a fear we need to swallow. We coexist with something like 40 trillion bacterial cells, which outnumber our own 30 trillion cells.
Put another way, the average 150 pound person carries with him about half a pound of bacteria. Something to weigh carefully as we think about ourselves, and our relationship to our environment.
OK you ask, what does our inner ecosystem have to do with the ecosystem beyond ourselves?
A lot of the answers to this question are not known at this point as scientists feverishly work out the complex workings of our microbiome.
The Human Microbiome Project, funded by the U.S. National Institute of Health, is characterizing the genetic diversity of human microbes. Scientists are also studying links between microbiome health and environmental health.
It is clear that exposure to chemicals in the environment such as arsenic, heavy metals, pesticides or any chemical with antibiotic properties (including antibiotics) can have harmful effects on the good bacteria within, especially early in life.
So our environment early in life is critical as the microbiome is built up from transfer of the mother’s inner biota to the child’s as well as transfer from the environment. There are some good bacteria in soil so you don’t always need to panic if your child inadvertently eats dirt.
Diet is critical as most of the microbes are holed up in our digestive system, and don’t appreciate some of the unhealthy food tossed down there that may also be produced in ways that are unhealthy to the environment.
The bottom line is that everything is connected to everything else. So anytime we mess with the connections that foster healthy environments, it could be costly to ourselves in ways we can hardly imagine, especially considering we cannot even see the trillions of bacteria each of us carry.
So, yes, you are an ecosystem. Take good care of your trillions of tiny friends.
David Clements, Ph.D. is Professor of Biology and Environmental Studies at Trinity Western University