Influence of gastric acidity on bacterial and parasitic enteric infections. A perspective

The human body carefully regulates the internal pH of different organs to maintain homeostasis. For example, while the blood plasma maintains a neutral pH of 7, the stomach lumen has an acidic pH of 1.5 - 3.5. The low pH of stomach lumen helps kill pathogens in the food and break down complex food molecules.
The acid-secreting gastric mucosal epithelial cells (parietal cells) lining the stomach lumen maintain the low pH in the lumen. Numerous ion transporters and channels on these parietal...

Peptic ulcers are sores on the stomach's inner lining and the upper small intestine, which are the result of disruptions in the mucosal layer that houses parietal cells which produce gastric acid, and chief cells which secrete pepsinogen.
In the antrum region, G cells secrete the gastrin hormone that binds to gastrin-cholecystokinin-B (CCK2) receptors on parietal and enterochromaffin-like (ECL) cells in the fundic glands. Simultaneously, the vagus nerve releases acetylcholine, which binds to M3...

Gastritis is marked by disruption of the mucosal barrier that usually protects the stomach tissue from digestive juices and manifests in acute and chronic forms.
In acute gastritis, the gastric mucosa becomes swollen and red and undergoes superficial erosion. Superficial ulceration may lead to bleeding.
In chronic gastritis, persistent or repeated insults lead to chronic inflammatory changes and, eventually, thinning or atrophy of the gastric tissue.
Gastritis can stem from various causes, each...

The human gastrointestinal (GI) tract is characterized by distinct physicochemical conditions that shape its microbial communities. Among these, the stomach presents a particularly challenging environment for microbial colonization due to its highly acidic pH, ranging from 1 to 3. This extreme acidity effectively limits microbial density. However, certain acid-tolerant microorganisms are capable of surviving in this niche. Notably, Helicobacter pylori can colonize the gastric mucosa,...

Peptic ulcers are erosive lesions of the gastric or duodenal lining, most commonly caused by Helicobacter pylori infection. This Gram-negative, helical bacterium has adapted to survive the stomach’s acidic environment by producing urease, which converts urea into ammonia and carbon dioxide. The ammonia neutralizes gastric acid in the bacterium’s immediate environment, allowing colonization of the gastric mucosa. H. pylori attaches to mucus-secreting epithelial cells, penetrates the mucus...

The pathophysiology of gastritis begins with the colonization of the stomach lining by Helicobacter pylori (H. pylori). This bacterium spreads mainly via the oral-oral route through saliva or shared utensils, and can also be transmitted in overcrowded or unhygienic environments through contaminated water, despite its brief survival outside the body.ColonizationOnce ingested, H. pylori enters the stomach and begins colonization by navigating through the mucus layer lining the stomach wall. It...