When most people think about concussions, they picture the brain, headaches, brain fog, maybe some light sensitivity. What rarely comes up? The gut.
But here’s the thing: concussions aren’t just a head injury. They’re a whole-body event. And more and more research is showing that one of the most overlooked parts of recovery happens in the gut.
Wait, What Does the Gut Have to Do With a Brain Injury?
A lot, actually.
There’s something called the gut-brain axis, which is basically a superhighway of communication between your brain and your digestive system. When you hit your head, the inflammation and neurological stress don’t stay in your skull. They travel. And your gut feels it.
Recent research has found some wild stuff, like a 2023 study from Loyola University showing that after a brain injury, the gut microbiome (that community of bacteria living in your digestive system) actually changes. More harmful bacteria show up, and helpful compounds like bile acids drop. That throws digestion off, increases inflammation, and makes it harder for your body to heal.
And (one of my favorite data points), about 90% of serotonin (the feel-good brain chemical) is made in your gut. So when your gut’s off, your mood can be, too.
The “Leaky Gut” Connection
Brain injuries also mess with the lining of your gut, making it more permeable, a condition often called “leaky gut.” That means stuff that shouldn’t be getting into your bloodstream (like toxins or undigested food particles) starts leaking in. Your immune system goes on high alert, and inflammation ramps up right when your brain is trying to heal.
A 2024 study on military personnel exposed to repeated low-level blasts (think mild TBIs) showed that markers of gut permeability were elevated immediately after impact. Earlier research even found that patients with more severe TBIs had worse gut barrier function and that it was linked to their long-term outcomes.
Why This Should Matter to All of Us
Gut health isn’t just about avoiding bloating or taking probiotics. It’s tied to brain recovery, mental health, and even long-term risk for things like autoimmune conditions and neurodegenerative diseases. That’s a big deal.
If we want to give people the best shot at healing after a concussion, especially athletes, students, or military service members, we have to stop treating the brain in isolation. Supporting gut health needs to be part of the plan.
So, What Can We Do?
If you or someone you know is recovering from a concussion, don’t just rest and hope for the best. Ask about ways to:
- Support the gut microbiome
- Reduce inflammation
- Strengthen the gut lining
- Get the right nutrients in to help the brain heal
Because at the end of the day, healing the brain starts with healing the whole body.
Let’s start thinking that way.