I’m five years old, waiting alone in my mom's office at the Zen Buddhist practice center she helps run. I don’t like being alone here. There’s a poster on the inside of the office door that I can never bring myself to look at straight-on and unflinchingly; I can only glance at it sideways with horror and fascination. It shows eight or ten illustrations forming a time-lapse, beginning with a Buddha-like figure meditating under a tree. In the first frame, the figure dies, and each subsequent frame shows it in a more advanced state of decomposition. Its skin turns red and then a mottled blue. Foxes and squirrels carry away its intestines. Soon it is just a skeleton there, in a sitting position under the tree. Finally, even the skeleton disintegrates, leaving only dust. I look at this time-lapse in the same way I would look at myself in the shower or the mirror. The figure is nondescript, so it’s a little easier to imagine that it could be my body under that tree. I suppose if I needed to put it into words, I would be asking, what is this body, really? At what point does the disintegrating skeleton stop being me? When my skeleton turns to dust, have “I” been destroyed?
We can think about the same question, in a less morbid way, through food and digestion. When you eat food, at what point does it become part of you? When it enters your mouth? When you swallow? When the former-food exits your stomach? Of course, the nutrients absorbed from the food become part of you, but at what point? If those time-lapse images presented a vision of the body’s decay into the environment, then digestion is the decay of the environment into the body. What about poop, or the pounds of dead skin (one pound a year!) that are constantly flaking off us everywhere, onto tables and chairs, into our clothes, coming to rest in the lint screen of the dryer? Food and waste form a constant process of decay and renewal, with no permanent elements. Did this skin and feces stop being me when my body decided it was no longer useful? Or am I flushing a piece of myself down the toilet?
As soon as we enter the realm of digestion, the self-other dichotomy quickly becomes indistinct, and it’s unclear who died under that tree in the first place. As Buddhist monk and peace activist Thich Nhat Hanh reminds us, “When we look deeply into living beings, we find that they are made of non-living-being elements. So-called inanimate things are alive also.” I depend on so much in order to exist that there is no separation between me and other things: Either there is no me, or everything else is also me. Growing up in a Buddhist community, I was often reminded of this philosophy. Although I’ve thought about these ideas less habitually now that I’m in college, they were still the first thing on my mind when I learned that bacteria in my intestines are controlling my brain.
100 trillion bacteria live in a human body, most of them in the intestines. The study of the gut-brain link is a burgeoning field, and the past decade has seen a spike in both scientific journal articles and dieting website listicles on your crucial entrails. According to the Journal of Medicinal Food, our gut microbiome is intimately tied to brain function: Gut bacteria directly stimulate neurons, sending signals to the brain via the vagus nerve, which influences the timing and continuity of non-REM sleep. In other words, our guts allow us to get in a few hours of deep sleep before we begin to dream. Biologists have found a growing number of links equating gut composition with fear, stress, and mental illness: A recent study published in Nature Microbiology links depression to a deficiency in two types of gut bacteria. Moreover, genetic variation between humans is surprisingly small for organisms that are so supposedly complex, which has led to speculation that humans’ so-called complexity may be fully dependent on our inhabitant microbes, especially our gut bacteria.
This news—apparent bacterial domination of the human mind—seems alarming when surrounded by ideologies that privilege hyper-individualism, where the concept of individual leadership appears more important than community. Unless I happen to be reflecting on gut-self oneness, I tend to think of my thoughts and moods as belonging to an individual Me. If I'm sad and can't place why, I'll roll with it and spin vast philosophical justifications of why I'm supposedly a terrible person. Perhaps it’s better to think of this sadness as a message from my intestines. From one perspective, bacterial control of my brain sounds insidious, but from another perspective, their message could be constructive: They might be “asking” that I eat more fiber to restore balance to my bacterial population levels. We are engaged in symbiosis, and therefore they aren’t separate from me. For every mood that seeps from the bacteria into my mind, they rely on my nutrients to live. “As we open and empty ourselves, we come to experience an interconnectedness,” writes Jack Kornfield in the Buddhist magazine Tricycle. “Each experience and event contains all others.” If I consider the Buddhist philosophy of interconnectedness that I learned growing up, it’s possible to construe the gut-brain link as comforting rather than threatening.
I’m ten years old, climbing the ash tree in my backyard. Growing up, I’ve had a close relationship with this particular tree. By age ten, I’ve memorized all the routes up the various verticals, gradually growing until I can bridge the gaps between specific branches. But today, once-reliable branches crack under my weight. The canopy has thinned out, the leaves are dying, even some of the upper verticals begin to topple. Suddenly I see the source of the problem: a complex of small holes, mathematically precise, drilled by some unknown entity, killing branches as they girdle them, allowing sap to flow down the trunks. Tree specialists later told me that birds —yellow-bellied sapsuckers—have been drinking the sap. By the time I know this, it is too late to do anything.
Symbiosis is not a concept specific to human bodies, of course. Gut flora serve as one case study for a process of interconnection that is perhaps more easily exemplified by entities in the (so-called) natural world. Human intestines are the latest in a long list of systems that have been misconstrued as isolated elements, and the effects of this misconception are often destructive. Another such system is trees in forests, which are engaged in a fascinating exchange with fungi. While some species of fungi attack plants, around 90 percent of Earth’s plants are tied in mutually beneficial relationships with fungal spores. In exchange for a slice from a plant’s sunlight-generated sugars, fungi help plants grow and absorb more water. Plants share fungi between each other as well. In 1997, Suzanne Simard of the University of British Columbia found that trees can exchange nutrients via a fungal connection that's now colloquially referred to as the “wood wide web.” One teaspoonful of forest soil, according to Peter Wohlleben’s The Hidden Life of Trees, contains miles of such fungus threads. Shaded seedlings wouldn’t survive without larger trees sending them nutrients through the communal fungal network, and plants can even use fungi to send warning messages to one another about potential pests. One of the factors that made the ash tree in my backyard particularly vulnerable to sapsucker woodpeckers was its lack of involvement in such a forest network. Urban planners are not concerned with matters of forest symbiosis. Assuming that the trees are individuals, we’ve failed to realize their collectivity until now. And although there are important differences between trees and intestines, ignorance towards both of their multifaceted livelihoods is a product of the same hyper-individualized mindset that rashly assumes the human brain to be autonomous and supreme.
Trees are abstract, and it’s hard to equate them to humans in the first place. Termites, perhaps more relatable but equally misconstrued, also form similar systems of interdependence. According to an in-depth 2018 Guardian article exploring these oblong white critters, these systems are also reliant on fungus to function. When European colonizers first sliced open the mounds of Macrotermes termites in sub-Saharan Africa, they projected their own social hierarchies onto the bugs, labeling various “individuals” as workers, soldiers, kings, and queens. Today, popular perceptions of insect colonies often continue to mis-imagine them as miniature monarchies. But writer and naturalist Eugène Marais, in his 1937 book The Soul of the White Ant, argued that monarchic thinking obscured the true nature of the mounds. He called the termite mound a “composite animal,” with the hard-packed outer dirt as the skin, the central fungus as the stomach, the workers as blood cells, the soldiers as an immune system, and the queen as an ovary. Whether Eugène’s organ-centric analogies offer a perfect analog for the multifaceted tasks of termites is up for debate. But regardless, the projection of anthropocentric images onto insect colonies—whether it involves analogies of monarchies or factories—obscures the reality of the cell-like behavior of bugs.
Both trees and termites function as components of meta-organisms. Humans are caught in a similar dance with our guts: Bacteria are dependent on our bodies to survive, and in exchange they digest our food, regulate our sleep, and keep us healthy and alive, making ours a mutually beneficial relationship. If there are ways in which humans could be seen as meta-organisms too, without a conventional individual self, maybe we should stop anthropomorphizing ourselves so much. Like bugs and plants, we too are caught in a web of indivisibility, living as constant echoes of our surroundings without any discreet, isolatable elements.
Descriptions of symbiotic interconnectedness and porous meta-entities can easily be likened to idealized images of peace and harmony as some natural order of the universe. There are those who would accuse me of being a naive hippie by arguing for oneness at all. ‘Nature’ is often held up as either end of an extreme: absolute oneness or absolute individualism. On the flip-side of peaceful idealism, the non-human world is also depicted as an anarcho-capitalist free-for-all, ruled by natural selection and held up as a justification for the continued existence of hyper-individualism and oppression. This view is equally misguided. Absolute peace and absolute violence are human-produced concepts, and the real world lies outside both of them. On the one hand, all the scenarios I’ve mentioned contain violence in some way: Different species of trees out-compete one another for shade; termites tear down trees; sapsucker woodpeckers also eat trees; and, if left outdoors in the right place, the human body is eaten after death by those foxes and squirrels from the time-lapse illustration. But on the other hand, examples like plants, bugs, and your guts challenge this oppressive simplification. The Zen Buddhist teachers in my life have also taught me about the importance of balancing seemingly contradictory truths. We musn’t get lost in the absolute truth of oneness, for the relative truth of everyday functioning is equally important.
The idea of oneness, when properly balanced with relative experience, does not imply a passive peacefulness, but rather inculcates social responsibility. Ideals of interconnection have the potential to reveal an innate urgency to problems of unjust violence against people everywhere, regardless of whether I appear to be directly affected. If the self does not end at the body, then hoarding wealth, acting only on one’s desires without regard for communities, and benefiting from oppressive systems without working to dismantle them, are all revealed to be self-destructive actions. If everything is, in a sense, my body, then the bursting of a Canadian pipeline sends oil into my bloodstream. Oneness is absolute truth. And relative truth—the specifics of the stories in the moment—is equally important. People experience violence differently based on identity and ideology, and the fact that violence disproportionately affects some more than others is just as important as the idea of interconnection. Both of these concepts are crucial if I am to incorporate the truth of oneness into a political agenda, if I am to actually learn something from trees and termites rather than treating their functioning as fun facts.
Fast-forward to whenever I die. Given new information on gut bacteria, I see that time-lapse artwork on my mom’s old office wall in a new light, for bodily disintegration is spearheaded by these very same bacteria. The moment “I” die, my gut flora go rogue. They start to digest my body from the inside out, beginning with the intestines, then the surrounding tissues, and, finally, making their way through capillaries, destroying my heart and brain. Some of them were beneficial over the course of my life. Others were simply waiting in my gut, biding their time until this moment. Like the figure under the tree in that time-lapse illustration, they open up my former body to the elements.
This image might seem terrifying. A National Geographic blurb titled “You're Surrounded by Bacteria that are Waiting for You to Die,” written with all the sensationalism of a horror movie trailer, describes the process this way: “As soon as you die, your body essentially gets its first break from a war that it has been fighting every moment of your life.” That logic is superficially sound. Were it not thanks to our immune system, our body's resident bacteria would infect and kill “us.” But the essentialization of “war,” the assumption of a battle against outsiders, misses out on the ways digestive bacteria not only benefit us, but are integral to our well-being and consciousness. What right do I have to believe that I am at war with my bacteria when, as I write this, they are not only digesting my food, but possibly crucial to my very thoughts? Seeing existence as war is inaccurate and harmful; I’m not fighting to stay alive, I’ve always been alive in some form or another. Thich Nhat Hanh also writes, “We think that we exist only from this point in time until this point in time, and we suffer because of that notion. If we look deeply, we will know that we have never been born, and we will never die.”
Reframed this way, the time-lapse of the decomposing meditator doesn’t display an ending, but another step in a symbiotic process. That way, it’s easier to not be alarmed if I imagine that person as me. Rather than believing myself to be fighting to exist as an “individual” against all odds, I try to see decomposition as one last stroke of symbiosis. Bacteria have given me my body. One day, I will give it back to them.
SEAMUS FLYNN B’21 is about to go poop now.