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Interesting Digestive System Facts You Should Know

Medically reviewed by Jezreel Esguerra, MD · General Practitioner

Written by Mayvilyn Cabigao · Updated Dec 08, 2022

Interesting Digestive System Facts You Should Know

Most of you know a little bit about the digestive system and gut health, but there is still a lot to learn. Know other interesting digestive system facts that range from the informative ones to the funny ones. 

What is the digestive system?

The digestive system is responsible for extracting nutrients from the food and drink you consume. These nutrients are further broken down into even smaller units so that the body can absorb them, and convert them into energy for cell growth, repair, and production of antibodies.

Here are other interesting digestive system facts. 

1. Your intestines can stretch up to 25 feet long

In the human digestive system, the small intestine can stretch up to 7 meters or 22 feet long on average, and the large intestine is about 1.5 meters or 5 feet long. The length of the large intestine is almost as tall as the average Filipino, around 5 feet and 1.57 inches.

2. Stomach acid is so strong it can dissolve your skin 

The stomach acid is made up of lipase, pepsin, and hydrochloric acid. When measured in pH level, the stomach acid ranges from 1.5 to 3.5

But why doesn’t the acid burn your stomach? This is because the stomach is protected by a layer of sticky gel-like mucus called the gastric mucus. This mucus keeps the stomach acid and enzymes intact. 

When the gastric glands secrete less gastric mucus, the stomach acid and enzymes may disrupt the lining of the stomach, causing acid reflux and ulcer.

3. The gut is home to a variety of bacteria

When we hear the word bacteria, we assume that it is bad for our health. However, in the digestive system, there are approximately 300 to 500 good bacterial species that live in the gut, comprising nearly 2 million genes. These help breakdown food and kill harmful viruses, bacteria, and toxins that you consume. 

4. The digestive system does not rely on gravity

Gravity is essential to keep us on the ground. However, our digestive system does not depend on gravity to function. Peristalsis is the process responsible for moving solids and liquids through the digestive tract. It does so through the wave-like motion of the muscles.

The strong muscles in the digestive tract are capable of functioning even if you eat upside down. Although it is uncomfortable and not recommended for people with GERD, you can still give it a try. 

5. You can produce over a liter of saliva a day

The major salivary glands produce 0.5 to 1.5 liters of saliva a day. That is equivalent to 7 to 8 glasses of water or the recommended water intake of an adult in 24 hours. 

6. Your stomach can expand to carry 4 to 5 liters of food

The stomach can stretch to accommodate the amount of food we eat. It can comfortably store 1 liter of solids and liquids. However, it can further expand to hold 4 liters of food when we eat more. 

When the stomach is full, it tends to press against the other organs, causing discomfort. That is why you feel sleepy, tired, or lethargic after a heavy meal.

7. Borborygmi is the scientific term for the noises your stomach makes when you are hungry

When you feel hungry, you usually tell people that your stomach is “growling.” This phenomenon is called borborygmi. This happens when the brain sends a signal to your digestive system to prepare for food. 

Aside from hunger, this sound may also be caused by digestion problems and the hot air trapped inside the small intestines. 

8. Saliva protects your organs from possible acid damage caused by vomiting

Do you ever wonder why you produce more saliva when you feel like throwing up? Salivating prepares your other organs like the throat, mouth, and teeth from the acidic contents of the vomit.

The acid from your stomach is strong and harmful, that is why more production of saliva is needed to coat the surfaces where vomit will pass. 

9. Farts are smelly because of the gases produced by bacteria

Burping and flatulence occur when the excess air you swallow while you eat, drink, smoke, or talk, is released through the mouth or rectum.

The odor that you sometimes smell when you flatulate is caused by bacteria and the gases they produce inside the intestines. 

10. The digestive system is prone to more types of cancer than any other part of the body

Gastrointestinal (GI) cancer pertains to the group of cancers that affect the digestive system. Many cancers that develop in the body originate in the digestive system. 

GI cancer is generally considered a public health concern due to high mortality and low survival rates, specifically for esophageal, stomach, and colorectal cancers. 

Key points

The digestive system is amazing and complex! It is good to know interesting digestive system facts, how digestion works, and all the other small things our gut does for us – aside from processing our food for our body to use.


Hello Health Group does not provide medical advice, diagnosis or treatment.

Medically reviewed by

Jezreel Esguerra, MD

General Practitioner

Written by Mayvilyn Cabigao · Updated Dec 08, 2022

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