According to neuroscientists the functioning of our body and of our mind are closely linked at our brain level. Any action, physical (movement) or mental (thoughts), from us is controlled by our brain and is realized through a series of physical and chemical reactions. Enzymes make biochemical reactions possible under the strict conditions (of body temperature, pressure, composition and concentrations of nutrients available ...) in which human life is allowed to take place. There are two main types of enzymes: digestive and systemic enzymes. A lack of enzymes causes metabolic disorders. A deficiency in digestive enzymes may cause indigestion, constipation, diarrhea, flatulence, lactose intolerance, heartburn, gastro esophageal reflux, peptic ulcers, and spasms.