In a murine model of iodine-induced autoimmune thyroiditis, a ketogenic diet reduces RORγt and IL-17 expression while increasing FoxP3 and IL-10 expression, resulting in a shift from pro-inflammatory to regulatory immune responses in the thyroid microenvironment.

When the body eats a very low-carb, high-fat diet, it starts producing a molecule called beta-hydroxybutyrate. This molecule stops damaged thyroid cells from releasing a signal called HMGB1. Without that signal, immune cells don't activate a protein complex called NLRP3, which normally triggers inflammation. With less inflammation, the environment in the thyroid stops pushing immune cells to become Th17 cells that attack the gland. Instead, immune cells turn into Treg cells that calm down the immune response. This shift reduces harmful proteins like IL-17 and increases protective proteins like IL-10 and FoxP3, restoring balance in the thyroid.