Each of us can be considered a walking repository of microbes, yeasts and viruses. Up to 40 trillion microorganisms live in humans.
Do microbes control people?
There are 21 thousand genes in the human genome. For comparison: the roundworm Caernorhabditis elegans has 20.5 thousand genes, and the “water flea” Daphnia has 31 thousand. But, despite the quantitative similarity, none of the representatives of the animal world can speak and it is difficult to think, as homo sapiens does.
There is no single set of microbes, and the microbiota (earlier it was called microflora - Ed.) Of each of us is as unique as fingerprints, although it changes throughout our lives.
Dense intestine
It is home to about a thousand species of microorganisms. We cannot live without them: they break down dietary fiber molecules, inactivate enzymes and toxins, and help the synthesis of vitamins in the body. Intestinal bacteria can affect the central nervous system, contribute to the development of anxiety disorders, depression, autism, but also strengthen the immune system.
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Bacteria of two types predominate among the inhabitants of the intestine, the balance of which determines the weight of a person.
There are much less microorganisms in the stomach: its acidic environment is not to many to taste. However, the now "fashionable" bacterium Helicobacter pylori has perfectly adapted to it. Now it is known for sure: it is she who is to blame for stomach and duodenal ulcers, gastritis and even stomach cancer. True, 80 percent of carriers of Helicobacter pylori do not have any stomach diseases. But people without it are at risk. Scientists have also identified a link between the disappearance of Helicobacter pylori from the gastrointestinal tract and the development of asthma.
Small skin lodgers
Some microorganisms prefer to settle on human skin. They become a cordon sanitaire for internal organs, protecting us from pathogens.
However, they can also reward us with skin conditions, from acne to dandruff, and are also responsible for the unpleasant smell of sweat.
The settlement of microorganisms on the skin depends on the living conditions. Thus, propionic acid bacteria feeding on the oil of the sebaceous glands select the skin of the face and back.
And corynebacteria and staphylococci love high humidity and feed on nitrogenous compounds from sweat fluid - therefore, they prefer the navel, armpits and popliteal fossa.
Our small skin lodgers are very diverse. It turns out that even in one person, the germs on the right hand are significantly different from the germs on the left hand.
The composition of skin microorganisms in different people differs on average by 85 percent and is unique for everyone. This led biologists from the University of Chicago to an unexpected conclusion: using the microbiota imprint, you can search with an accuracy of 70% … criminals.
Each mouth has its own streptococcus
Approximately 800 species of microorganisms have taken root in the human mouth, and the most numerous here are streptococci, which cause caries and serious sore throat, up to acute pharyngitis and necrotizing fasciitis.
But streptococci also bring benefits, driving away hostile pathogenic bacteria and viruses. Other microbes, by secreting nitric oxide and thereby relaxing the arteries, help regulate blood pressure. But they, as it turned out, cause migraines.
And if the bacteria Klebsiella pneumoniae gets from the mouth into the intestines, ulcerative colitis or Crohn's disease (inflammation of the gastrointestinal tract. - Ed.)
Today it has been proven that the community of microorganisms in the oral cavity overlaps in different individuals by 40-50 percent. Of course, the longer people live together in marriage, the more similar the microbial communities in their mouths.
It turns out that microorganisms - inhabitants of a micromegalopolis in the form of a human body - control it from birth to death, which means they have a considerable influence on our whole life.
Grigory Sarkisov