The Liver: The Gateway for Everything you Eat
■ Foods that you have eaten enter the body through the liver
“Your stomach is a part of you, too.” That is a literal translation of a common Japanese admonishment against overeating, equivalent to “moderation is its own medicine.” From another point of view, the stomach and intestines, while “inside” the body, are actually nothing more than a path for food that can be thought of as being outside the body.
Food that is eaten is converted into easily absorbed components by the digestive fluids in the stomach and intestines. It then passes from the intestinal wall through the portal vein to the liver. It is through the metabolism of the liver that food is first processed into nutrition that can be useful to the body.
Nutrients produced in the liver enter the circulation system—the arteries through which blood flows pumped by the heart—and are carried throughout the body, where cells in each organ use them. Substances that are unneeded by the body and components such as bile acid, which help digestion, and which are made by the liver, are returned to the intestines as bile.
■ Enterohepatic circulation connects the Earth and cells
The flow between the intestines and the liver is called the enterohepatic circulation. It brings into the body substances that are needed by the body and expels from the body substances that are unneeded. Waste products in the intestines become stool, which is used by other organisms, and so in this way the enterohepatic circulation is an important loop that connects the outside world and the inside world.