the proteolytic enzyme secreted by the Pancreas and intestinal act best in slightly alkline conditions pH 7-9. The overall pH of the food from stomach entering the intestine will be lower than that required for optimal function of these proteases. On entering the intestine from the stomach, the food is rapidly mixed with the pancreatic secretion and with bile from the gall bladder. These fluids are responsible for increasing the pH of the intestinal contents. Also, fluids secreted from the intestinal wall may also play some role in neutralizing the gastric acid.