... that the skin of a 70 kg man covers an area of 2 sq.m. but the surface of his intestine amounts to approximately 300 sq.m.

... that this 70kg man consists of 12 trillion cells, but his intestine is populated by 100 trillion microbes, of which about 500 species are known.

... that 80% of our acquired immunity originates from contact with germs in the intestine.

... that the body produces about 113 billion defense cells per day in the bone marrow to protect us against germs from the intestine, from the skin and from the mucous membranes of our respiratory system.

... that the bacterial colonization of the human intestine is as individual as a fingerprint.

... that the human body contains approximately ten thousand different proteins, which are composed of 20 different amino acids.

... that probably the smallest creature in the world measures only 400 millionths of a millimeter. This bacterium was discovered in the sea near Iceland.

... that each day 200 billion red blood cells are made from the bone marrow of a healthy person.

... that every liter of blood contains 5 trillion (5.000 billion) red blood cells. They have no nucleus and therefore cannot proliferate. They have a lifespan of 120 days.

... that the human heart pumps about 7000 liters of blood every day. It pumps the blood through the entire body within one minute. An average heart is about the size of a fist and weighs just 300 grams.

... that the surface of human lungs is 70 to 100 sq.m. which corresponds to the size of a tennis court.

... that man moves 43 muscles when he frowns and only 17 muscles when he smiles.

... that man consists of 60% water, of 19% nitrogen-containing compounds (nucleic acids, proteins, peptides, amino acids, etc.) of 15% of lipids (fats), of 1% carbohydrates (sugar) and of 5 % minerals (Na, K, Mg, Ca) and trace elements (e.g. iron, copper, etc.).

... that our conscious thinking can process 70 bit/s. The unconscious, however, can process about 11 million bits/s.

... that a micro liter of blood (about the volume of a pinhead) contains up to 5 million blood cells. The blood transports oxygen, nutrients, pollutants, heat and body waste and is a channel for our immune system and coagulation system.