written by Elise Miller, MEd
CHE Director
The experience of teenage girls in northern India, growing up in traditional upper-caste Indian homes but being exposed increasingly to Westernization, was the focus of my graduate research 25 years ago. My particular area of interest was exploring their experience of “self” and how it impacted their choices and values. What I learned is that “I” for these girls meant something far more permeable, relational, and inclusive of other than the very individualistic concept of “I” which is so fundamental to Western thought and civilization.
As Western biological science has begun to grapple with the complex interplay of multifactorial contributors to health and disease, defining “I” or what an individual actually is has become increasingly challenging as well. Dr. Scott Gilbert, professor of biology and author of Ecological Developmental Biology, brings attention to this in his article, “A Symbiotic View of Life: We Have Never Been Individuals.” He notes that Western scientific disciplines have used a certain concept of “individual” as a basis for research since the inception of modern science. Whether the entity being studied was a lichen or a human, it was considered until very recently a distinct organism.
As more research on the microbiome and other “omes” emerges, however, our perception of what comprises an individual becomes far blurrier, and the biological interplay of symbionts and holobionts takes center stage. Like the understanding of “I” among the teenage girls in India in my own study, the biological concept of a single entity in Western science is becoming more boundary-less and relational. In fact, as Dr. Gilbert and other biologists point out, it’s increasingly clear that an organism can no longer be studied as a distinct individual. The previously assumed mono-genomic organism is conceptually wrong. Instead, we are all made of up a community of organisms, which are genomically interconnected and mutually interdependent in a variety of ways.
So what does this have to do with chemical contaminants and their impact on human health? Everything. For example, the human body (the holobiont) is made up of 90% microbes (the symbionts) each with their own metabolisms. This means that we can no longer be concerned just with how industrial compounds might disrupt gene expression in humans. Instead, if an exposure to a chemical undermines the hormonal signaling in a microbe, which we are dependent on for digestion, then our ability to digest properly is disrupted. To take this one step further, since many studies have shown how important the gut-brain axis is, our brain function may also be impaired. Along these lines, one study published recently suggested that “germ-free” mice can have autism-like symptoms, which disappear when the bacteria is put back in the mice.
If this isn’t mind-boggling enough, microbes, because they have their own metabolisms, can also influence which genes are passed on. This means, as Dr. Gilbert has purported, that they may have an evolutionary impact by selecting for genetic variations that benefit certain symbionts.
And we thought animal research was already complex enough! But now, in essence, scientists are realizing you not only have to control for the feedstock and other environmental factors in a study, but for the particular microbes within the animal being studied.
OK. I didn’t intend to offer a mini-science lecture, and I’m the last one who could speak on this with any real authority. But I personally found this so conceptually revolutionary because of its implications for our work in environmental health. This way of thinking, based on my reading of this emerging science, underscores why the impact of environmental exposures on human health may prove to be even more significant than we already thought. Not only are we concerned about the effect on an individual, but on all of the organisms within that so-called “individual” as well. In short, how we perceive “I”, as I learned from those Indian girls many years ago, shapes how we see the world and the choices we make and the value we place on relationships. Maybe as other scientific disciplines begin to take into consideration this inherent interconnectedness–something ecologists have done for so long–we may start making smarter decisions about what we put in our environment, knowing that it not only effects our health and that of future generations, but the health of everything else that makes us “us.”
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