The First Signal
The Sensor Array and the Gut
The body isn’t a vehicle. It’s not a thing you drive around while the “real you” sits at the controls. It’s a system, and more than that—it’s a sensor array.
At the center of that array is the gut.
We’ve long known, even if only intuitively, that the body registers things the mind misses. A stomach drop before bad news, a tightening chest before a hard truth, a flood of relief before words even form. But intuition wasn’t enough to earn scientific respect. Not until relatively recently.
Over the last two decades, the field of microbiome research has exploded. Findings that were once fringe now make their way into textbooks and clinical guidelines: that gut bacteria influence mood, cognition, immunity, and even social behavior. That neurotransmitters like serotonin and GABA are produced in large quantities in the gut. That the vagus nerve transmits data from the body to the brain far more than the reverse.
In other words, the gut speaks first. The body knows before you do.
The Biology of a Gut Feeling
Roughly 90% of the body's serotonin—a neurotransmitter tied to mood, digestion, and sleep—is produced in the gastrointestinal tract¹. GABA, another key inhibitory neurotransmitter often used to modulate anxiety, is also synthesized by gut-residing microbes². These substances don't just float meaninglessly in the abdomen—they act on the enteric nervous system (sometimes called the “second brain”) and communicate directly with the central nervous system via the vagus nerve.
This isn’t metaphor. It’s neurobiology.
The gut-brain axis, once dismissed as a niche curiosity, is now central to how we understand mental health. Clinical trials are investigating the use of probiotics as adjunct treatments for depression and anxiety. The term “psychobiotics” has entered the lexicon³. The question is no longer whether the gut affects the brain—it’s how deeply and in what ways.
Yet culturally, we still default to the idea that cognition lives in the brain and the rest of the body is just along for the ride.
Living Against the Signal
Like a lot of people, I spent years managing symptoms instead of listening to signals. Caffeine for fatigue, alcohol for overstimulation, food as distraction, digital noise for everything else. None of that is unusual. It’s the norm.
But beneath all that compensation were systems trying to stabilize, to warn, to repair.
I started drinking young. Not from trauma, just availability, peer modeling, and a vague sense that life needed a filter. By my teens, I was self-medicating the normal stress of growing up with substances that dulled perception—particularly gut signals. Digestive trouble became part of the background noise. Bloating, irregularity, food sensitivities—none of it read as meaningful. Just things to tolerate.
Only when the signals got too loud to ignore did I start to see them as communication, not interference.
Systems Thinking at the Personal Scale
When I encountered systems thinking—not in a book, but as a way of making sense of everything breaking down at once—it changed how I viewed health. Not as something to fix piecemeal, but as the interaction of inputs, feedback loops, and regulation mechanisms.
The gut became the most obvious node in the system. But the system wasn’t just biological. It was social, psychological, economic. How I ate wasn’t just about nutrients—it was about schedule, emotion, money, time. How I digested depended not only on microbiota but on stress, sleep, movement, and alcohol.
Systems thinking is not a self-help strategy. It doesn’t give you hacks. It gives you complexity. But it also allows you to work at the level of structure instead of symptom.
Toward Function, Not Optimization
There’s a temptation to turn everything into a project of self-optimization. But I’m not interested in that anymore. What I want—and what I think many people want—is function. Coherence. A way to live without every part of you shouting over every other part.
Gut health is one place to start. It’s where a lot of the shouting happens. But it’s not about controlling it. It’s about understanding it as a signaling system embedded in a broader ecology—of bacteria, of nerves, of relationships, of habits.
If the body is a sensor array, the goal isn’t to override it. It’s to learn how to listen. Sometimes that means removing noise. Sometimes that means reinterpreting the signal. But most of the time, it just means paying attention to what’s already being said.
References
- Carabotti, M., Scirocco, A., Maselli, M. A., & Severi, C. (2015). The gut-brain axis: interactions between enteric microbiota, central and enteric nervous systems. Annals of Gastroenterology, 28(2), 203–209.
- Strandwitz, P. (2018). Neurotransmitter modulation by the gut microbiota. Brain Research, 1693, 128–133.
- Cryan, J. F., & Dinan, T. G. (2012). Mind-altering microorganisms: the impact of the gut microbiota on brain and behaviour. Nature Reviews Neuroscience, 13(10), 701–712.