We’ve all been taught that “germs” make us sick. But what if the real story isn’t about the invaders… but the environment they enter?
Enter: Terrain Theory.
This concept—originated by Claude Bernard and championed by holistic medicine—suggests that pathogens only thrive in weakened environments. In other words: it’s not just the bug, it’s the host.
Let’s explore what this means when it comes to gut health, neurotransmitters, and your adrenal system—because it’s more connected than you think.
🌿 The Gut as Terrain
Your gut microbiome is a living terrain—home to over 100 trillion microorganisms. When that terrain is nourished, diverse, and balanced, pathogens have less room to settle in or take over.
But when your internal soil is dry (low stomach acid), depleted (nutrient-poor), or inflamed (from stress, sugar, antibiotics, etc.), even small exposures can cause big symptoms.
Symptoms of a disrupted terrain:
- Frequent bloating, gas, or constipation
- Cravings (especially sugar, dairy, bread)
- Histamine sensitivity or food intolerances
- Skin issues, brain fog, fatigue
In this state, even “good” foods can cause symptoms—because your terrain is reactive, not resilient.
🧠 Neurotransmitters: Not Just a Brain Thing
Did you know over 90% of your serotonin and 50% of your dopamine is made in your gut? Neurotransmitters rely on a healthy terrain to synthesize, circulate, and function properly.
So when your gut terrain is off, it’s not just digestion that suffers. You may feel:
- Anxious or low for “no reason”
- Unmotivated or flatlined
- Irritable, moody, or stuck in overthinking loops
- Craving quick hits of sugar, caffeine, or validation
Balancing your terrain means you can rebuild neurotransmitter function—without needing to rely solely on external fixes.
⚡ Adrenals & Your Inner Ecosystem
Think of your adrenals (which produce cortisol, DHEA, and adrenaline) as part of your internal emergency system.
When your terrain is strong, your adrenals can rest. But when your body is in chronic survival mode (poor gut health, low blood sugar, infections), your adrenals have to compensate for a poor terrain—which eventually leads to burnout, inflammation, and immune suppression.
This is why people with SIBO, candida, leaky gut, or food sensitivities often also have HPA Axis dysfunction or “adrenal fatigue.” Their terrain is under constant threat, so the whole body stays in fight-or-flight.
Healing the Terrain
Instead of just attacking bugs with antifungals or antibiotics (germ theory), functional healing asks:
💭 “What made the terrain vulnerable to begin with?”
So we support:
- Minerals and stomach acid to rebuild digestive fire
- Detoxification in increase absorption and productivity
- Nervous system tools to switch out of sympathetic overdrive
- Whole foods, prebiotics, and probiotics to re-seed biodiversity
- Emotional clearing to reduce internal inflammation
Because when your terrain is whole—bugs don’t stick, symptoms fade, and your mood lifts from the inside out.
Bottom Line
Germ theory blames the invader.
Terrain theory empowers the host.
If you’ve been chasing symptoms or bugs without lasting relief, maybe it’s time to shift from war to gardening. Your body isn’t broken—it’s a brilliant ecosystem just waiting to be restored.
Jade Green, TNC, CHHC
