All human mucous membranes are colonized by bacteria called microorganisms. The body needs these microorganisms because they perform important functions in our body.
Already at the beginning of the last century, the Nobel Prize winner E. Metchnikow found that a high number of lactobacilli in the intestine has a positive effect on health and promotes a long life. At the same time, H. Tissier found that diarrheal diseases in infants could be successfully treated using bifidobacteria. This was the beginning of research into human intestinal flora.
Human skin and mucous membranes are colonized by numerous bacteria, the majority of which are found in the intestine. The intestinal flora consists of over 400 different species.
The small and large intestines have a surface area of approximately 400 square meters – here 100 trillion unicellular organisms (microbes) live together with the multicellular human being.
The biodiversity of these microbes is large and their tasks are diverse
- Prevent bacterial overgrowth – microbial barrier – protection against settlement and multiplication of pathogens; growth inhibition through the production and release of microstatic and microcidal substances such as short-chain fatty acids, hydrogen sulfide and hydrogen peroxide.
- Immunomodulation and stimulation – constant training of the natural immune defenses, that is, stimulation of antibody formation and production of macrophages, these are also called phagocytes.
- Vitamin production – production of important vitamins – the vitamin K by coli bacteria, vitamins B3, B5 and folic acid by clostridia species and vitamin B12 by some species of lactobacilli. However, the amounts produced in the process are only of minor importance and contribute far from covering the daily requirement of these vital substances* .
- Nutrient and vital substance supply of the large intestine mucosa.
- Promoting the metabolism of the intestinal wall by substances formed by the bacteria.
- Promoting intestinal motility
* Vital substances include vitamins, minerals, trace elements, vital amino acids, vital fatty acids, etc.. At the same time, our intestines provide habitat and food for microorganisms.
This give and take between humans and microorganisms is called symbiosis (living together).
A symbiosis is always characterized by the fact that both humans and bacteria derive a benefit from living together.
