The Real Reason You Have Brain Fog Most people assume their brain fog is from stress or lack of sleep, but one of the biggest hidden causes is biofilm — a sticky, protective layer built by bad bacteria, parasites, yeast, and pathogens in the gut. Biofilm acts like armor. It hides harmful microbes from your immune system, blocks nutrients from being absorbed, and releases toxins that travel straight to the brain. The result? Foggy thinking, poor memory, sluggish focus, headaches, anxiety, irritab