Happy Gut, Happy Mind?
You’ve probably heard the phrase “happy gut, happy mind.” But what does that actually mean? And is it really true? Let’s break it down in a way that’s clear, research-backed, and (I promise) digestible.
My Story: When Stress Shows Up in My Gut
I didn’t fully realize the significance of the mind–gut connection until I began noticing it in my own body. One of the first ways stress shows up for me is bloating.
It’s not that my body has changed overnight—it’s more the feeling of being a little puffy or not fully in my body, even though two days earlier I was slipping into the same jeans just fine.
For me, this often happens during busy, high-stress stretches—extra social events, a little more drinking than usual, or stretches where my schedule feels busier than normal. I used to thrive in those seasons, and in many ways I still do, but I’ve learned to recognize the impact they have on my digestion. I’m still learning, always. Every experience is a teacher—and for that, I’m grateful.
Why the Gut and Brain Are Always Talking
Your gut and brain are in constant conversation. They’re linked by the vagus nerve (think of it as a superhighway of signals) and supported by trillions of microbes living in your gut microbiome.
This system is sometimes called your “second brain” because it doesn’t just digest food — it also influences mood, focus, energy, and how your body responds to stress.
The Serotonin Story
Here’s where things can get confusing. You may have heard that about 90% of serotonin is made in your gut. That’s true — but it doesn’t tell the whole story.
The serotonin made in your gut (sometimes called peripheral serotonin) is incredibly important. It helps regulate digestion, appetite, and how your intestines move food along.
But here’s the catch: gut serotonin can’t cross the blood–brain barrier. That means the serotonin in your gut isn’t the same as the serotonin acting in your brain.
So no, your gut isn’t directly “pumping mood chemicals” into your head.
Still, your gut health matters deeply for your mood. Why? Because your microbiome helps shape things like:
Tryptophan availability (a building block for serotonin in the brain)
Inflammation and immune signaling (which influence mood and stress)
Signals through the vagus nerve (your gut literally “talks” to your brain)
So while it’s a myth that gut serotonin itself makes you happy, it’s absolutely true that your gut influences mood in powerful, indirect ways.
Stress Goes Both Ways
The mind–gut connection is a two-way street.
When the gut is out of balance, it can influence mental health—contributing to anxiety, brain fog, or low mood.
And when your mind is in a chronic stress state (anxious, overwhelmed, run down), those signals travel down the vagus nerve and impact digestion, motility, and even the diversity of your microbiome.
That’s why stress and digestion often flare up together. Your gut and brain are never separate—they’re always in conversation.
How to Support the Mind–Gut Connection
You don’t need to overhaul everything. Small, consistent rituals make the biggest difference.
Eat more fibre-rich foods. Think seeds, apples, leafy greens, oats, beans. They support blood sugar, mood, and feed your gut microbes.
Include fermented foods. Sauerkraut, kimchi, kefir, and miso can help nourish a diverse microbiome.
Slow down at meals. Digestion starts before your first bite. Breathing, pausing, and being present all help your body digest and absorb nutrients.
Notice your stress cues. Is bloating showing up? Are you eating in a rush? Awareness is the first step toward change.
Final Thoughts & Takeaways
The mind–gut connection isn’t hype—it’s real, fascinating, and deeply empowering once you begin to notice it in your own body.
No, gut serotonin doesn’t directly boost your brain’s serotonin. But your gut still plays a major role in how you feel, think, and show up in the world. And just as importantly, your mind influences your gut too.
✨ Takeaway: Support one, and you’re always supporting the other.
With love and intention, always.
Ashley Lougheed
Root Cause Nutritionist, CNP