This is a common condition in the elderly which comes from the inability to secrete sufficient stomach acid to kill bacteria. Ingested bacteria can thus survive and reside in the stomach and the upper part of the small bowel. This problem affects approximately 20% of people between 60 and 69 years of age, and 40% of people over 80. These bacteria, which are not killed by the normal stomach acid, interfere with the absorption of vitamin B12. Putting these patients on antibiotics to reduce the number of bacteria returns their B12 levels to normal. The deficiency of vitamin B12 may not be severe enough to show up in the blood, but it can be associated with psychiatric dementias. These deficiencies may be disguised as Alzheimer's disease or senile dementia.
Atrophic gastritis is characterized by atrophy of the stomach wall with reduced or absent gastric acid secretion. It may also lead to reduced levels of intrinsic factor.
Lactobacillus gasseri was the only one among several organisms administered that was successfully implanted in healthy and atrophic gastritis individuals.
Gastric autoimmune disease has been classified into types A and B, based on the changes in different portions of the stomach. Patients with antibodies to parietal cells (PCA) or intrinsic factor, or both, have atrophy of the fundal mucosa (Type A) and a very high rate of pernicious anemia, often associated with other autoimmune endocrine disorders. In cases of Type B gastritis, PCA are lacking and there is no association with pernicious anemia or other autoimmune endocrine disorders.
Edema may be due to low levels of circulating proteins from poor protein digestion.
Stomach acid is required to enhance the absorption of minerals such as calcium. Reduced calcium absorption encourages bone loss.
There may be a localized deficiency of Vitamin C in atrophic gastritis. Recent evidence suggests that beta-carotene and/or vitamin C along with vitamin E may reverse or reduce the risk of atrophic gastritis and/or gastric cancer. Another study showed vitamin C levels to be low in atrophic gastritis and Helicobacter Pylori infection.