The connection between the microbiome and behavior is wilder than you think.
Okay, stay with me on this one because it’s going to connect some dots you might not expect.
I was recording a podcast episode recently with Claire Forsyth, an animal kinesiologist from Australia, and we got deep into the emotional world of animals — how they carry patterns, how they mirror their humans, how anxiety in pets often has roots that go way beyond what we see on the surface.
And the whole time we were talking, the scientist in me kept circling back to something I see in my clinic every single day:
The gut and the brain are in constant conversation.
We call it the gut-brain axis, and it’s one of the most fascinating areas of research happening right now — in human medicine and in veterinary medicine.
Here’s the short version: your pet’s gut microbiome (the trillions of bacteria living in their digestive tract) produces neurotransmitters — the same chemicals that regulate mood, behavior, sleep, and stress. We’re talking about serotonin, dopamine, GABA. A massive percentage of your pet’s serotonin — the “feel-good” chemical — is actually produced in the gut, not the brain.
So when the microbiome is out of balance? That communication gets disrupted. And what we often see on the outside looks like:
- Anxiety that doesn’t respond to training or behavioral work alone
- Restlessness, pacing, inability to settle
- Aggression or reactivity that seems to come out of nowhere
- Changes in appetite or energy that feel “off”
- Chronic GI issues alongside behavioral changes
Sound familiar?
I’ve had so many cases where a pet came in for “anxiety” or “behavior problems,” and when we ran a microbiome test, we found a gut that was completely out of balance. Dysbiotic. Key species missing. Inflammatory bacteria overgrown.
And when we addressed the gut — through microbiome restoration, nutrition, sometimes fecal transplant therapy — the behavior shifted too. Not always overnight. But meaningfully. Sometimes dramatically.
Why I think this matters for you:
If your pet has anxiety, reactivity, or behavioral challenges that aren’t fully resolving with training or medication alone, it might be worth looking at what’s happening in their gut.
A microbiome test is simple — it’s just a stool sample. And what it tells us can completely change the direction of care.
I’m not saying gut health is the answer to every behavioral issue. It’s not. There are emotional layers, environmental layers, relational layers (like Claire’s beautiful work explores). But the gut is a piece of the puzzle that gets missed way more often than it should.
And honestly? Addressing it often makes all the other layers of healing work better.
If you’re curious about whether a microbiome test might be a good fit for your pet, just email us .We can walk you through it and help you figure out the best next step.
And if you want to hear the full conversation with Claire about the emotional side of the pet-human bond, it’s on the podcast — My Dog Is Better Than Your Dog.
Because your pet’s wellness isn’t just physical. And it isn’t just emotional. It’s the conversation happening between the two. 💜✨
With love,
Dr. Lily 💜
P.S. — One of my colleagues in the masterclass recently said something that stuck with me: “My behaviorist colleague has found that a lot of anxiety cases have underlying GI discomfort.” That’s it. That’s the whole point. The gut and the brain are one system. Let’s start treating them that way.
