What do people have in their bodies

Our bodies - more bacteria than humans?

Whether at work, doing sports, shopping or even in the shower - we are never alone: ​​Billions of bacteria and fungi - or microbes for short - are constantly “accompanying” us. Microbes are tiny living beings that cannot be seen without a microscope and that occur in our nature, in animals and even in humans. Countless types of bacteria and fungi live in and on our body. Most of them are not harmful, but make a valuable contribution to our health and well-being.

A balanced relationship

Since a publication by microbiologist Thomas Luckey, it had been assumed that the number of microbes living in the body exceeded the number of human cells by ten times. Researchers at the Israeli Weizmann Institute and the Hospital for Sick Children in Toronto recently put this number into perspective: They are more likely to assume one One-to-one ratio out.

The basis of their investigation is a 20 to 30 year old “average man” weighing 70 kilograms and 1.70 meters tall. According to estimates by the scientists, this consists of 30 trillion body cellsthat are colonized by about as many or slightly more bacteria (39 trillion / about 2 kg of our body weight). The team around Ron Milo, Ron Sender and Shai Fuchs can well imagine that another personb only contains half as many or even double the amount of microbes. The reasons for fluctuating numbers are diverse and range from different lifestyles to changes due to illness. Even going to the toilet can seriously affect the ratio, say the scientists.

Fig .: Number and weight of cells in the human body - This varies greatly in humans. However, you can see that a large proportion is not synonymous with a high weight. Source: Spektrum.de

Bacteria: at home everywhere

Bacteria live on our skin, our mucous membranes and in our internal organs. And they are represented in numerous ways. About 9,000 species can be counted on our tongues alone, and in the crook of the elbows there are still almost 3,500 trunks. On the skin, for example, the “good” bacteria form a protective coat that helps us to fight off pathogens. Meanwhile, other microbes break down sweat. Incidentally, the resulting smell varies from person to person and can be responsible for who we can “smell good”, that is, who we find likeable.

Our intestines: the largest collection point for microbes

Most of the bacteria that colonize us, however, cavort in the Intestines: They form the so-called "Intestinal flora”. This provides us with enzymes without which our digestive tract would not be able to break down and utilize food. For example, unusable carbohydrates are converted into long-chain fatty acids that provide us with energy. Some microbes produce vitamins and fight back as important part of our immune system pathogens that cause disease. Meanwhile, other bacterial strains are busy breaking down cholesterol and environmental toxins.

If we did not get bacterial support, we would have to consume significantly more food in order to be supplied with all the necessary nutrients. In the history of human development, which was mostly characterized by a lack of food, this digestive aid through bacteria represented a decisive advantage for survival. In today's industrial nations, however, these conditions can also be increased Problems lead: Because of the Excess of food and nutrients fat cells swell, the metabolism is unbalanced and the immune system is boosted. The result: permanent inflammatory reactions throughout the body and thus increased Disease Risks how diabetes or lipid metabolism disorders.

Bacteria affect our state of mind

According to the latest scientific findings, the well-known saying “love goes through the stomach” should rather be “Love goes through the gut" be called. As has now been found in several studies, bacteria in our intestines not only affect our physical health, but also ours State of mind. Accordingly, not only does our psyche have an impact on our digestive tract, but also the other way around.

As has been established so far, our intestines can “make contact” with our brain via its complex nervous system made up of numerous cells that can secrete signaling molecules or perceive signals, and in this way control emotions and feelings. Among other things, it seems to have an influence on the ingredients and consistency of the foods we eat. These exert an influence on the Communication signals between the intestinal bacteria and our brain out. Many scientists even assume that a disturbed intestinal flora increases the risk of mental illness such as depressions increases significantly. However, research in this area is still in its infancy. Progress has been made especially since the introduction of new techniques, such as 16S rRNA sequencing, which provides much more precise results. So it will be exciting to see what other findings will be gathered here in the future.

Conclusion: (bacterial) friendships have to be cultivated

Even if the advertising of cleaning products often wants to create a different image: Bacteria have long since lost their image as nasty pathogens. The positive influence of certain microbes on the human organism is now undisputed. It is therefore advisable to carefully consider the use of antibiotics. It goes without saying that dangerous pathogens must be combated. But every time antibiotics are used, not only the pathogens are killed but also many “sympathetic relatives”. For this reason, disinfectants should also be used sparingly in everyday life: it is usually sufficient to wash your hands thoroughly with hot water and soap.