Your digestive tract is just like a studio apartment!

For a common student, the area of the inner surface of the digestive tract is between 180 and 300 square metres. For scientists, it is actually as small as a studio apartment!

Debunking a long-held belief, which is part of reference works and textbooks, scientists at the Sahlgrenska Academy at University of Gothenburg have used refined microscopic techniques that indicate a much smaller area.

"Actually, the inner surface of the gastro-intestinal tract is only as large as a normal studio apartment," scientist Lars Fandriks announced.

The digestive tract, which passes from the mouth through the esophagus and onwards through the intestines, has a length of about 5 metres in a normal adult, and is built up with many folds and protrusions.

Scientists Fandriks and Herbert Helander used quantitative microscopic techniques to determine that the surface area of the gastro-intestinal tract in healthy adults is "only" between 30 and 40 square metres.

By far, the greatest part of this is the small intestine.

The area of the large intestine is approximately 2 square metres, while the mouth, esophagus and stomach amount to less than 1 square metre.

It may appear to be simply a curious fact, but the "dimensions of the inner surface of the gastro-intestinal tract are important for the uptake of nutrients and drugs", the researchers emphasised.

The new information would help us understand how the mucous membrane protects the body from harmful factors in the intestinal contents, Fandriks added.

Since the past measurements were carried out either during post-mortems or during abdominal surgery, when the tissue is relaxed, it is easy to obtain misleading measurements, Helander noted.

According to them, the new dimensions are valid for a healthy "average" adult as the length and surface area of the digestive tract differs from person to person.

The article has been published in the Scandinavian Journal of Gastroenterology.