Do you ever feel like you’re brain is wading through mental molasses? Forgetful. Confused. Fatigued. It’s called brain fog, and if you suffer from it regularly, you’re not alone. But here’s the disturbing part, conventional medicine rarely talks about: Recent research indicates the fog in your brain might be coming from your gut.
Yes, you read that right, more specifically, from a condition called Small Intestinal Bacterial Overgrowth (SIBO). If you’re suffering from digestive disturbances and your mind feels sluggish, SIBO may be the hidden cause that’s robbing you of clear thinking, energy, and even your joy.
The Gut-Brain Connection
Your gut and brain are connected through what has recently been coined the gut-brain axis. This two-way street communication system involves nerves, hormones, and the immune system. When the gut is inflamed, your brain feels the effects.
In a 2020 review published in the journal Nutrients, the authors explain how gut-derived inflammation and gut bacteria imbalances can disrupt mental function. Disturbances in gut health trigger the release of toxic compounds called cytokines that disrupt nervous system messengers. In short, when your gut is off-balance, your brain becomes “foggy.”
SIBO triggers inflammation throughout the entire body. The inflammation mounts a release of endotoxins (such as lipopolysaccharides or LPS) into the bloodstream—a process called leaky gut. These endotoxins cross the blood-brain barrier and spark inflammation in the brain as well. The result? Poor concentration, memory lapses, mood swings, and chronic fatigue.
Brain Fog: A Symptom, Not a Diagnosis
Brain fog is not a disease; it’s a symptom of an underlying root cause that is routinely overlooked by modern medicine. Conventional medicine treats “brain fog” as a vague, standalone issue. But functional medicine goes deeper—we ask why the brain is inflamed or underperforming. More often than not, the problem stems from the digestive tract.
In my practice, I’ve seen patients with diagnoses ranging from fibromyalgia to depression, but the underlying root cause was SIBO and leaky gut. Once the gut was repaired, the mental fog lifted, energy returned, and life was restored with clarity and purpose.
Scientific Evidence Linking SIBO to Brain Fog
I have two studies to show you that will help you to understand the link between SIBO and Brain Fog with scientific evidence.
Study #1: Gut Dysbiosis and Brain Inflammation
A 2022 article published in Frontiers in Neuroscience reported disturbances in the gut microbiome—bacteria in the gut triggered consequences in the brain.
The researchers observed that SIBO can affect memory and brain function through the production of toxic compounds like D-lactic acid. Elevated levels of D-lactate are common in SIBO and lead to confusion and disorientation in both children and adults.
Study #2: SIBO and All Facets of Learning and Memory in Fibromyalgia Patients
A 2023 study in the journal Pain Medicine examined women with fibromyalgia and found a high incidence of SIBO. Those who tested positive for SIBO had significantly more severe brain fog symptoms than those who did not.
Researchers concluded that “addressing SIBO may be a new approach to improving cognitive symptoms in fibromyalgia patients.”
The takeaway? SIBO doesn’t just cause digestive distress—it impacts your brain’s ability to function.
What Causes SIBO To Get Brain Fog?
The following are several root causes that can set the stage for SIBO:
- Antibiotic overuse – Kills good bacteria, allowing harmful ones to overgrow.
- Low stomach acid – Prevents proper digestion and allows bacteria to grow.
- Slow gut motility – A sluggish small intestine allows unwanted bacteria to hang out in the small intestine and multiply.
- Poor diet – A diet rich in “carbs from hell”—refined sugars and processed grains.
- Stress – High cortisol levels affect gut motility and immune function.
How to Clear the Fog and Heal the Gut?
Here’s the good news: brain fog due to SIBO is reversible. But you must go upstream and fix the root cause.
Step 1: Identify the Underlying Root Cause
Functional medicine testing, like the lactulose or glucose breath test, can confirm SIBO. I recommend working with a practitioner who understands functional medicine, not just symptom management. I’d be honored to help you, but please get to a good doctor.
Step 2: Remove the Overgrowth
Natural antimicrobials such as high-quality oregano oil, berberine, and garlic extract can be effective alternatives to antibiotics. I have seen many cases of SIBO that didn’t respond to antibiotics, but herbal medicine resolved.
Step 3: Repair the Gut Lining
Support the mucosal lining of the gut with nutrients like aloe vera, slippery elm bark, and zinc carnosine. These help to heal the gut lining and reduce inflammation.
Step 4: Replace “Carbs from Hell” with “Carbs from Heaven”
Choose foods that nourish your gut, not inflame it. These include:
- Steamed vegetables
- All types of berries
- Well-cooked quinoa, millet, brown rice, and buckwheat
Avoid Foods Like:
- Refined sugar and artificial sugars
- All gluten grains
- Artificial sweeteners
Step 5: Rebuild the Gut-Brain Connection
Meditation, deep breathing, prayer, and movement—all part of my Supernatural Morning Routine—are proven to reduce cortisol and promote vagus nerve tone, improving both gut and brain health. (You can get a FREE copy of my Supernatural Morning Routine book inside my Gut 911 Rx community. Simply go to TheOtherSideofMedicine.com). The book and the community are FREE.
Final Thoughts
You don’t have to live in a mental fog. If your mind feels cloudy and your body bloated, your small intestine may be hijacked by harmful bacteria. Don’t just pop another pill or settle for vague encouragement from rushed appointments. Get to the root cause.
As I always say: Stick with us, heal your gut and fuel your health. Clear the fog, fix the gut, and reclaim your clarity—naturally, powerfully, and permanently.