Brain fog is used to describe a collection of symptoms that range from an inabilty to think clearly or to read and comprehend. Inflammation of the brain is the reason this happens. The cause of the inflammation can vary from person to person. The gut-brain axis refers to a bidirectional pathway between the gut and the brain. There is continuous communication between the two. When there is inflammation in the gut from processed foods, gluten, sugar or food intolerances/allergies the brain gets inflamed too. Gluten, by itself, will cause inflammation to the brain through the gut system. Infections, stress, an underlying disease, a diagnosed disease, medications, mold,  heavy metals/toxins and mental health issues can result in brain fog.