The bacteria will command the parade: what are the microbes capable of in our body

Speaker: Valentina Buchneva, Head of the Eurasian Division of Bosnalek Pharmaceutical Company

The human body as an ecosystem does not come down to our own body. In tandem, he works with a whole "ensemble of the microworld" - symbiotic bacteria and other microorganisms. Their diversity is impressive: suffice it to say that in the aggregate the “internal population” of the intestine alone contains 150 times more genes than our own genome.

New studies show that bacteria can not only regulate digestion, but also influence our behavior and thinking. The intestinal microbiota alone - the so-called set of microorganisms in one of the systems of the human body or group of organs - is capable of such that sometimes you doubt whether it is smarter than our brain. Let's see what bacteria that coexist with us can do.

Regulate our brain

Unreasonable bacteria intimidatingly easily affect our minds. More precisely, on the central nervous system. Moreover, apparently, without symbiotic microorganisms, we would have problems not only with digestion, but also with thinking.

Scientists from the Karolinska Institute (Sweden) performed an experiment — albeit on mice — some of the rodents were raised in sterile containers without contact with bacteria, and some under normal conditions. When the animals became adults, it turned out that individuals from the first group did not show the usual reaction to danger for mice and, on the whole, were more reckless than representatives of the second group. Moreover, if the mouse, which was deprived of the usual microflora for its species, was allowed to “pick up” these bacteria in adulthood, its behavior did not return to its natural norm. Without the formation of a complete microbiota in experimental animals, the psyche underwent irreversible changes.

Also, bacteria zealously “lobby” their own nutritional interests, again acting on various systems of our body: nervous, immune, etc. During the study, under the supervision of Joe Elcock of the University of New Mexico, a hypothesis was put forward that bacteria can achieve their acting on the vagus nerve connecting the brain with internal organs.

It turns out that the plan to switch to healthy lifestyles threatens to violate not only deep psychological reasons, but also the most material ones that are important for the inhabitants of our gut. At the same time, scientists emphasize, a person with a change in diet can change the composition of the microbiota in his intestines. And a scientifically based approach to the diet, coupled with taking a combination of probiotics and prebiotics (in short - drugs with beneficial bacteria and nutrients for such bacteria, respectively) can form the most favorable microflora for us.

Change our state of mind

Scientists from the University of Copenhagen set out to determine whether the bacterial background of mammals affects their resistance to stress. And they established: it affects, and how.

The experiments were usually carried out on mice. Scientists have intentionally placed mice in "stressful conditions." Comparison of samples of mouse droppings showed that the number of Alistipes bacteria increased in the intestines of experimental animals during stress exposure: in humans, an increase in their level accompanies gastric upset.

Meanwhile, researchers from Columbia University in New York studied the intestinal microbiota in hundreds of volunteers, both healthy and suffering from chronic fatigue syndrome. As measurements showed, representatives of the second group in the gastrointestinal tract showed an increased content of the previously mentioned Alistipes and a number of representatives of the genus Bacteroides, while the concentration of bacteria of the genus Faecalibacterium and Bacteroides vulgatus was reduced. Moreover, the imbalance was manifested the stronger, the more pronounced the symptoms of the disorder. Apparently, such a bias in the composition of the intestinal microflora causes changes in metabolism, due to which chronic fatigue syndrome occurs.

As you know, depression can be associated with a number of factors - from stressful events in human life to a genetic predisposition. A number of bacteria in the human intestines help fight this scourge. It has been established that Oscillibacter bacteria produce a substance resembling gamma-aminobutyric acid - a neurotransmitter that acts as a sedative and inhibits the processes in our central nervous system.

Prepare us for birth

A quarter of a century ago, the prevailing opinion in science was that before birth the fetus is formed under sterile conditions. However, as was proved later, even during pregnancy, the mother’s body passes the baby a part of its microflora.

Bacteria begin to influence us long before we are born. So, an international team of scientists led by Ruth Lei from Cornell University (USA) studied how the composition of the intestinal microbiota in pregnant women changes. According to the data obtained by the research team, the bacterial background in the mother’s body is adjusted in such a way that the sensitivity to insulin decreases and, as a result, fat accumulation is easier for the late stages of the gestation of the child. Under normal conditions, such a dynamics would be cause for alarm, but during pregnancy, on the contrary, it increases the chances of a successful development of the fetus.

A couple of years later, the Kierstey Ogord team from Baylor College of Medicine in Houston, USA, found that a whole community of bacteria lives in the placenta. Including those that serve to assimilate nutrients. What is surprising, in composition, microorganisms are close to those that inhabit the oral cavity of an adult.

At the same time, individual microorganisms can also disrupt the bearing of the child. According to the results of several studies, bacteria that cause gum inflammation in periodontitis increase the likelihood of premature birth. In a pregnant woman suffering from this dental disease, pathogenic microflora with blood flow can get into the placenta - with a risk of starting labor before the due date.

Trainable for peaceful purposes

One gets the impression that bacteria affect our body almost more noticeably than the brain (by the way, the human intestinal microbiota is comparable in weight to it). And since the microbiota does not have a reason, then it is impossible to “negotiate” with it - only act on it chemically, for example, to take probiotics. However, scientists are groping for ways to seamlessly manage conglomerates of microorganisms.

More recently, a team of specialists from the La Sapienza University of Rome and the Italian Institute of Nanotechnology managed to draw a mini copy of Mona Lisa - and not just anything, but bacteria.

Instead of paint, the population of Escherichia coli was used, it is also Escherichia coli. Contrary to popular belief, most of its strains, by the way, are not harmful to humans. Scientists have chosen this bacterium for experiments for the reason that it is able to move extremely fast, covering a distance of ten times its length in a second. They also modified E. coli by incorporating a special photosensitive protein into its genome.

Researchers placed a colony of E. coli on the screen and projected a picture on it - in black and white. Under the influence of artificial lighting, microorganisms on the substrate began to move, and the faster, the stronger the light stream. In the area where the light intensity was lower, the bacteria moved more slowly, therefore they accumulated in greater concentration - and thus the density of “live paint” at a particular point in the “canvas” corresponded to how dark the color in the same place on the original portrait was.

The invention seems pure fun only at first glance: similar technologies can be applied, for example, for the targeted delivery of drugs using bacteria to foci of infection within the body or even to individual groups of cells.

By the way, such a "peaceful training" already leads to tangible results: it is this principle that underlies biocenosis-saving technologies. Biocenosis-saving technologies are the opposite of antibiotics. Their main principle of work is the creation of drugs that take care of the natural microbiota and selectively act only on pathogenic bacteria. According to this principle, our drug "Lizobact" acts to help make up for the lack of lysozyme - an enzyme that is found in human saliva and kills pathogenic bacteria - for example, SARS pathogens.

Currently, many pharmaceutical companies are already engaged in projects in the field of biocenosis-saving technologies. These technologies offer not only the safest approach to the treatment of diseases, but also new directions in the development of pharmacology in general. The diversity of microbiota and the flexibility with which it can potentially be regulated opens up a huge space for improving the body and improving our condition without mechanical invasive intervention. And with bacteria, we, after all, have been together throughout our history.


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