Allergy is a problem faced by a huge number of people. Most often, it manifests itself in the form of a runny nose, cough, redness of the eyes and other unpleasant symptoms. Most often they appear at certain times of the year when certain plants bloom. Sometimes there are more serious health problems that can be life threatening – these are asthma, autoimmune diseases, etc.
The reasons are the malfunctioning of the immune system. In a recent study, scientists at Rutgers University found a relationship between allergies and antibiotic use in early childhood. As you know, antibiotics have a negative effect on the intestinal microflora. At the same time, the microflora plays an important role in the immune system, especially at the stage of its formation.
How the gut microflora is related to immunity
The microflora affects a variety of processes in the body, as it was recently found out, even the work of some parts of the brain depends on it . But what is the relationship between microflora and the immune system? In fact, everything is very simple. The task of immunity is to protect the body from dangerous microbes, viruses, mutated cells, etc. At the same time, the intestines contain a huge amount of bacteria, and they are necessary for the body. Therefore, the immune system faces an important task – to learn to distinguish between beneficial bacteria that live in the body and harmful ones that come from outside.
Thus, by interacting with the intestinal microflora, the immune system is trained to be selective. That is, before attacking the bacteria, it makes sure that it is really dealing with the enemy, and not with beneficial bacteria. Allergies and autoimmune diseases are connected precisely with the fact that the immune system begins to attack any threats indiscriminately. As a result, even your own cells and harmless substances suffer. This is called hyperexcitability.
In other words, problems with the immune system arise due to the fact that at the stage of formation it did not have enough contact with bacteria (it does not matter “friendly” or “hostile”). This is called the excess hygiene theory, or hygiene hypothesis.
Is the hygiene hypothesis true?
There is controversy regarding this hypothesis, and scientists regularly conduct experiments to prove it or disprove it. In a recent study published in Mucosal Immunology , scientists from Rutgers University managed to provide convincing evidence that the theory is still correct.
As expected, the experiment was carried out on mice, or rather, small mice aged only five days. They were given the antibiotics azithromycin or amoxicillin along with water. Moreover, the dosage was therapeutic, that is, the same that is usually prescribed in the treatment of certain diseases.
After a course of “treatment” with an antibiotic, the entire intestinal microflora was not destroyed in mice, but it received a shake-up. The number of some bacteria must have decreased or even disappeared altogether.
Some time later, when the mice had already grown up, they were exposed to a common allergen – house dust, in which a dust mite lives. During this experiment, the researchers’ expectations were confirmed – in mice that received antibiotics, especially azithromycin, an increased frequency of immune reactions was observed, in other words, an allergy arose.
But maybe it’s not just immunity, but the spoiled microflora itself? To verify this, the researchers took adult mice and completely deprived them of their intestinal microflora. Then they transplanted them with microflora from those mice that were exposed to antibiotics in childhood and became allergic.
After that, adult mice with a foreign microflora were exposed to dust mites. It turned out that they did not react to the allergen in any way. That is, despite the replacement of microflora, their immunity remained the same, as it was formed in childhood. But the most interesting thing is that the offspring of these mice turned out to be predisposed to allergies.
The explanation for this is quite simple – mice receive microflora from their parents from the nest. But at parents it has been spoiled by an antibiotic. Accordingly, the immunity of the offspring could not form normally. To finally make sure of this, the scientists transplanted microflora into mice from healthy mice.
The offspring of such rodents, even after microflora transplantation, was not predisposed to allergies. That is, the transplantation of bacteria itself does not affect this in any way. From this we can conclude that antibiotics do interfere with the normal development of the immune system of children.
I must say, scientists are increasingly coming to the conclusion that the intestinal microflora plays a much more important role in the body than previously thought. According to some reports, even life expectancy depends on it .