High fat and high protein encourages candida to produce more damaging acid proteases and lipases(for people that have fungal candida). Excess fat can also overwork the liver with the extra bile production. A concentration of bile in the gut without it being properly absorbed/nuetralized can aggravate leaky gut. Gut inflammation can affect our mood..its the Gut-mind connection. Melatonin is something I use on occasion that helps a lot with late night gut inflammation. Excess protein intake can cause brian fog due to someone who has bad bacteria/candida producing too much ammonia. My brain fog is usually a result of too much simple sugars or excess protein. My Gut inflammation is usually a result of too much hard to digest fat,spices, irritating anti-fungals. Anti-fungals that cause an inflammation response can give me both head fog(too much histamine released) and gut inflammation. Every now and then a non-drowsy anti-histamine pill(allegra) can help with histamine related brain fog, but I don't like depending on those pills.