Digestibility of foods and grains is a hot area of research right now in human nutrition (and an area of academic research I am pursuing as well). The best answer I can give is, ...it depends. There are many factors such as time, pH, microbial activity, the number of activated enzymes, inactivated enzymes, water content, the crystalline structure of the carbohydrate, the crystalline structure of the mineral and antinutritional factors (insoluble fibers, phytates, tannins, etc) which may make the protein, carbohydrate, vitamin and minerals either more favorable or less favorable for absorptions. In addition, it also depends on the variety of the wheat, how it is processed, what was the method of cooking, was the pizza browned or charred, in addition to your own endogenous digestive capabilities to break down that food item, whether or not your body needs a particular molecule and can transport it, the efficiency of absorption and your own state of health at the time. I know I left your question vague but much of biology is conditional on the premise, "...it depends". In my professional opinion, any added bonuses from fermentation are going to be extremely minor and most likely offset by anti-nutritional factors produced during maillard formation while baking.