The tasks of the intestine
Everything we eat is inspected for usability and then broken down into its smallest parts -- sugar building blocks, amino acids and fatty acids -- so that these can be absorbed by the blood and made available to the body as energy.
Resorption of vital substances
The absorption of vitamins, minerals and trace elements is at least as important to the body as the absorption of sugar, protein and fat. The intestine can even synthesize some vitamins itself.
Protective barrier to the outside world
Although the intestine hides inside the body, it functions as a barrier to the outside world. The intestines remain a part of the outside world until the intestinal mucosa pass substances in a controlled manner to the blood and body.
Headquarters of the immune system
Eighty percent of our immune system is located in the intestine, which decides whether we stay healthy or fall ill. In a healthy intestine, there are three times more immune cells than in the spleen, bone marrow and lymph nodes combined. The intestine is the place where our organism processes most of the pathogens and toxins. And exactly here, at the border to the outside world, sit the guardians of our defense: The healthy bacteria, who ensure that our immune system is put on alert and stimulated when attacked.
Production of hormones, vitamins and enzymes
Not only hormonal glands but also our intestines produce important hormones, such as the stress hormone cortisol, the happiness hormone serotonin, and the sleep hormone melatonin. Additionally, the intestine produces many enzymes and coenzymes that play a central role in metabolism. Important vitamins such as vitamins B1, B2, B6, B12 and K, which we urgently need for our heart function and circulation, are produced by intestinal bacteria.
The bowel is a detox organ. Toxins from the liver and our entire metabolism system are eliminated from the body with our stool. That is why a good, regular emptying is so important. During constipation, toxins and all rotting, fermenting substances of badly digested food remain in the colon and effectually poison us. This auto-intoxication can be responsible for many diseases.
An optimal pH value in the intestine creates a life-friendly environment in which the good intestinal bacteria feel comfortable, allowing them to perform their tasks and at the same time preventing pathogenic germs from multiplying.
Intestinal flora and brain
Not only our head has a brain, but also our intestine! The intestine has many millions of nerve cells which act similarly to those in the brain: Experts therefore speak of the intestinal or abdominal brain, or the intestinal-brain axis. An imbalance of gut bacteria can impair mental performance or even lead to mental disorders and neurological diseases. People with intestinal diseases such as irritable bowel syndrome or Crohn's disease therefore often suffer from anxiety disorders or depression. Conversely, the microbiome can also promote the development of diseases such as multiple sclerosis or Parkinson's.