I have been in clinical research for the past 35-years. Most of the clinical studies were on digestive issues and allergies. The two main culprits that have surfaced that cause food allergies are Achlorhydria and Hypochlorhydria. Achlorhydria is the complete absence of Hydrochloric acid (HCL), in the gut. Hypochlorhydria is the reduction in the strength of the HCL, in the gut. Both of these conditions, will allow allergens, bacteria and pathogens to enter the small bowel, causing allergic reactions. When nutrients enter the stomach, they are mixed with HCL, pepsin and a host of other enzymes. The HCL breaks down the food into a thick liquid mass called chyme. The peptic enzymes break down proteins into peptones, which are in part the building blocks for the amino acids, necessary for sustaining life. Many proteins are allergens and will cause allergies, if they are not broken down and sterilized, by the action of the peptic enzymes and the HCL. Pepsin is most active in the conversion of proteins, when the strength of the acid is at 1.2 pH. As the strength of the acid diminishes, the peptic enzymes become less active, in the conversion of proteins. At pH 5.0 the peptic enzymes are completely inactive in the conversion process. Hypochlorhydria and Achlorhydria will allow raw nutrients that contain allergens, bacteria, and pathogen to enter the small bowel, resulting in allergic reactions and many other debilitating disorders. The symptoms associated with Hypochlorhydria and Achlorhydria are: nausea, reflux, anemia, vitamin and mineral deficiencies, gas, belching, bloating, abdominal pain, skin reaction, swelling of the lip, tongue, face, diarrhea and/or constipation, etc. Both of these condition can be caused by aging, proton pump inhibitors (PPIs), antibiotics, antihistamines, antacids and sedentary live styles. To find out if a person has Hypochlorhydria, or Achlorhydria is to have a pH diagnostic test, or pH gastrogram. The test will tell the doctor how your digestive system is processing what you eat and why you have allergies. There are digestive blogs on the web that have a lot of information on pH testing and gastrograms.