In view of the reaction mechanism proposed by Lewis, the reactions of metals and acids with certain species are very similar. In the Lewis mechanism, electron-deficient species such as metal cations, the hydrogen ion of acids and positively-charged species react with electron-rich species such as anions, hydroxide ions and molecules with free electrons to form new chemical bonds that even out the imbalanced electron distribution, in reactions like neutralization for acids and oxidation for metals (Whitten, 2004).
   
In the body, the production of acid for digestion is a well-regulated process, and the body has several organs and secretions that ensure that stomach acid levels do not get too high. There are possibly medications that could regulate the production of acid (probably antihistamines, according to someone I asked for opinion), but as these medications could upset the bodys proper functioning, neutralization of excess acid by the take-in of sodium bicarbonate seems to be better.
   
On the whole, the body can be thought of as one large chemistry set. The blood, for instance, is a complex system that exhibits fascinating chemistry, capable of delivering carbon dioxide out of the body via a chemical buffering system and also delivering oxygen to its parts via the binding of oxygen to an ion-molecule complex found in blood. Gastric acid is a solution composed primarily of hydrochloric acid. Urine is composed of organic urea and waste products dissolved in water.
   
The body is a well-regulated chemical system, and does not allow the presence of foreign chemical agents, which it rids itself of by metabolizing it into a form that it can easily dispose. Problem ensues when the product of metabolism is more toxic than the original compound. Taking in too much paracetamol, for instance, results in both liver failure and kidney failure, due to the liver being unable to neutralize the excess toxic product of paracetamol metabolism.