Low thyroid function also inhibits gastrin production which, in turn, can lead to hydrochloric acid insufficiency, which leads to poor protein digestion and mineral absorption which THEN leads to putrefied and otherwise poorly digested protein molecules creating irritation (and eventual leaky gut issues) in the GI tract and a more favorable environment for pathogens of all kinds....including yeasts. Protein here is not and never is the problem. Poor digestion is the problem. Hydrochloric acid can help immensely..