Stomach acid, or gastric acid, is a watery, colorless fluid produced by the lining of your stomach. It is highly acidic and helps break down food for easy digestion. It helps your body absorb nutrients more easily as food passes through your digestive system. Stomach acid is essential to break down everything from meat to tough, fibrous plants. Your body is designed to handle moderate levels of stomach acid so that it does not cause you any disease or health complications. However, those systems may not always work as well as they are supposed to. Drinking gastric juices with low or high levels of acidity can cause other health problems. Gastric Acid/vagotomy
Kills most organisms that enter the portal of entry, the stomach. In the setting of low or absent gastric acid, there is a high incidence of bacterial colonization of the upper small intestine. As a result, people with hypochlorhydria or achlorhydria, or people who use drugs such as proton pump inhibitors that block gastric acid secretion, are more prone to diarrheal illnesses. Gastric Acid/vagotomy
Control of Gastric Acid Production
At rest, the number of H+– K+ ATPases within the parietal cell membrane is minimal. The rest are separated into tubulovesicles in the parietal cell. Upon stimulation, the vesicles fuse with the cell membrane causing an increase in H+– K+ ATPase in the membrane, thereby increasing the movement of hydrogen ions into the stomach thereby increasing acid production. Gastric Acid/vagotomy
Increased production of gastric acid
There are three ways in which acid production increases. The first of these is via AC, which is released from the vagus nerve. It is first released during the cephalic phase of digestion, triggered by the sight or chewing of food, resulting in direct stimulation of parietal cells via the vagus nerve. It is also produced during the gastric phase of digestion when enteric nerves detect gastric dilatation, which stimulates the production of AC via the vagus nerve. Gastric Acid/vagotomy
A central regulatory pathway involves the hormone gastrin, which is released by G cells in the stomach. G cells are activated by the vagus nerve, gastrin-related peptides, and peptides in the stomach lumen produced by protein digestion. Activation of G cells leads to the production of gastrin, which is released into the blood and travels through the blood until it reaches the parietal cells. Gastrin binds to CCK receptors on parietal cells, which also increase calcium levels, thereby increasing vascular fusion.
Finally, enterochromaffin-like cells in the stomach release histamine that binds to H2 receptors on parietal cells. It increases fusion, however, unlike calcium in other ways, via a secondary messenger cAMP.
Decreased gastric acid production
There are several ways to reduce acid production.
The first of these is caused by the accumulation of acid in an empty stomach between meals. This increase in acid causes a decrease in pH within the stomach, which inhibits gastrin release through somatostatin production from D cells. Once the food is broken down in the chyme, it moves into the duodenum, triggering the intragastric reflex. This reflex can be triggered by small bowel distension if the upper intestine is more acidic, with the presence of protein breakdown products as well as more mucosal irritation. Inhibitory signals are sent to the gastrointestinal tract via the enteric nervous system, as well as signals to the medulla – reducing gastrointestinal vagal motility. The intragastric reflex is important in reducing gastric emptying when the intestines are already full.
The presence of chyme within the duodenum also stimulates enteroendocrine cells to secrete cholecystokinin and secretin, both of which play a variety of important roles in completing digestion, but also inhibit gastric acid secretion. Secretin is released by the S cells of the duodenum when there is excess stomach acid.
Other hormones, including glucose-dependent insulinotropic peptide (GIP) and vasoactive intestinal polypeptide, also act to reduce gastric acid production.
Causes of High Stomach Acid
There are several conditions that can lead to heartburn. Often, these conditions lead to the overproduction of the hormone gastrin. Gastrin is a hormone that tells your stomach to produce more acid.
Some of the most common reasons include:
- Rebound acid hypersecretion: H2 blockers are a type of medication that can reduce stomach acid. Sometimes, people taking this medicine may experience increased stomach acid. There is evidence that this may also occur after the introduction of proton pump inhibitors (PPIs), although this is controversial.
- Zollinger-Ellison syndrome: With this rare condition, tumors called gastrinomas form in your pancreas and small intestine.
- Some people with H. pylori infection may also have stomach acid.
- Gastric outlet obstruction: When the passage from the stomach to the small intestine is blocked, it results in increased stomach acid.
- Chronic kidney failure: In some rare cases, people with kidney failure or those undergoing dialysis may develop high levels of gastrin, which increases the production of acid in the stomach.
- It is also important to note that sometimes no specific cause of stomach acid can be identified. When the cause of a condition cannot be determined, it is called idiopathic.
Symptoms
Some of the symptoms that you may be suffering from stomach acid include:
- Nausea or vomiting
- Bloating
- Burning sensation in chest and stomach
- Diarrhea
- Loss of appetite
- Unexplained weight loss
- The symptoms of heartburn are very similar to those of other digestive conditions.
It’s always a good idea to see your doctor if you have persistent or recurring digestive symptoms. Your doctor can work with you to diagnose the cause of your symptoms and create a treatment plan.
Treatments for Gastric Acid
High stomach acid is often treated with protein pump inhibitors (PPIs).
PPIs have a trusted source of efficacy over H2 blockers. They are often given orally but may be given by IV in more severe cases.
If your stomach acid is due to an H. Antibiotics work to kill bacteria while PPIs will help reduce stomach acid production.
Sometimes surgery may be recommended, such as gastrinoma removal in people with Zollinger-Ellison syndrome. Additionally, people with severe ulcers may need surgery to remove part of the stomach (gastrectomy) or the vagus nerve (vagotomy).
If heartburn is one of your symptoms, you can make dietary changes to help ease your symptoms:
- Eat smaller and more frequent meals
- After a low-carb diet
- Limiting your consumption of alcohol, caffeine, and carbonated beverages
- Avoid foods that make heartburn worse.