Gastroenterology and Digestive Diseases

Helicobacter pylori Infection

Helicobacter pylori, a gram-negative, microaerophilic bacterium has co-existed within human stomach for thousands of years. They are accustomed to the harsh acidic environment of our stomach. The presence of H. pylori may go undetected as they hardly show any symptoms. But if there is an infection, it may cause acute gastritis with abdominal pain and nausea. While in its chronic stage, it causes non-ulcer dyspepsia, with symptoms like abdominal pains, nausea, bloating, and belching. H. pylori are also responsible for colorectal polyps and colorectal cancer. Cramps occur when the stomach is empty especially in the early morning and between meals. H. pylori use chemotaxis movements to avoid the highly acidic environment of the stomach by moving towards less acidic regions by burrowing in the mucous lining. H. pylori affects the linings of the stomach and duodenum by producing ammonia to regulate pH, which is toxic to the epithelial cells of the stomach and duodenum, besides, the proteases produce vacuolating cytotoxin A (VacA) which damages epithelial cells followed by disrupting the tight junctions thereby causing apoptosis, The colonization of the H. pylori in the stomach causes chronic gastritis. H. pylori invade the stomach during childhood due to contaminated water or food. Symptoms associated with H. pylori infections are anorexia, bloating, excessive burping, fever, heartburn, nausea and weight loss.