What's in Your Stomach's Gastric Juice?

Acids, enzymes, mucus, and more

As soon as you put food into your mouth, your stomach begins releasing gastric juices. This liquid mixture will help dissolve food once it reaches the stomach and the process of digestion begins.

A man holding his stomach in pain
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How You Make Gastric Juices

The food you chew and swallow is called a bolus. It mixes with the gastric juices secreted by special glands found in the lining of your stomach, which include:

  • Cardiac glands at the top part of the stomach
  • Oxyntic glands in the main body of the stomach
  • Pyloric glands in the antrum or the lowest part of the stomach

Each of the glands contains cells that make specific components that together are called the gastric juices.

Neck cells secrete bicarbonate and mucus. Parietal cells secrete hydrochloric acid. Chief cells secrete pepsinogen. Enteroendocrine cells secrete various hormones. However, not all stomach glands contain every type of cell.

Breaking Down the Gastric Juices

Gastric juice is made up of water, electrolytes, hydrochloric acid, enzymes, mucus, and intrinsic factor.

Hydrochloric acid is a strong acid secreted by the parietal cells, and it lowers your stomach's pH to around 2. Hydrochloric acid converts pepsinogen into pepsin and breaks various nutrients apart from the food you eat. It also kills bacteria that comes along with your food.

Pepsinogen is secreted by chief cells, and when it's in the presence of hydrochloric acid, it's converted to pepsin. Pepsin breaks apart tertiary and secondary protein structures to make it easier for the digestive enzymes in the small intestines to work later.

Gastric lipase is another digestive enzyme made by the chief cells. It helps break down short and medium chain fats.

Amylase is also found in gastric juices, but it isn't made by the stomach. This enzyme comes from saliva and travels along with the bolus into the stomach.

Amylase breaks down carbohydrates, but it doesn't have much time to work on the stomach because the acidity stops it. That's okay, though, because your small intestine introduces more amylase later on.

The mucus is secreted by the neck cells and helps coat and protect your stomach lining from the acid environment.

Intrinsic factor is secreted by parietal cells and is necessary for your body to absorb vitamin B-12. This is essential for healthy nervous system function and blood cell production.

It All Works Together

Your stomach muscles squeeze and churn to mix the bolus with all of these digestive juices.

The liquid mixture is called chyme. When it's ready, your stomach squirts the chyme into the small intestine where digestion continues and absorption of those all-important nutrients occurs. 

1 Source
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Willet SG, Mills JC. Stomach organ and cell lineage differentiation: from embryogenesis to adult homeostasis. Cell Mol Gastroenterol Hepatol. 2016;2(5):546-559. doi:10.1016/j.jcmgh.2016.05.006

Additional Reading

By Shereen Lehman, MS
Shereen Lehman, MS, is a healthcare journalist and fact checker.