It's been a long time since: peasant children are less prone to allergies and asthma. So far it has been said that the diverse blend of microorganisms on farms is the reason for this. By contrast, excessive hygiene is responsible for a sudden increase in the number of diseases. But now the study shows that this view is too short: Protective microbes are also found in urban households. Indeed, it is rarely but as sufficient as a possible starting point for prophylaxis.
No more dirt, than it is. This is an inexcusable way to sum up the edition of an international research team that appeared this week in the prestigious magazine "Nature Medicine". Researchers led by Pirkkij Kirjavainen from the National Institute of Health and Social Welfare in Kupiou, Finland, studied the composition of domestic dust in 395 Finnish households. It has been shown that suburban children with lower risk of asthma at home had a similar microbial blend in home dust than their peers in the village. No amount or variety of bacteria played a role. Only the composition of the microbe mixture was decisive.
In the second step, the researchers surveyed their results with 1031 German children. It has been confirmed that those with a lower risk of asthma at home have a similar composition of microorganisms than in Finnish village houses.
Protection is not provided by individual bacteria, but by community of microorganisms.
"This is not, as has long been assumed, a special way of living in farms that protect us from asthma," says co-author Erika von Mutius. Von Mutius is a pediatrician and allergist in Munich at the Helmholtz Center and the Ludwig-Maximilians-Universität and coordinated the German part of the study.
Although the research team found certain groups of bacteria that partially live in the soil in nature and probably enter the living space from the outside. "But we could not identify any bacterial species responsible for the protective effect," von Mutius says. "These are the microorganisms that cause it." It is considered that the protective effect comes from changes in the human immune response. Whether the metabolites, surface proteins or other bacterial components are key, is still open.
There are many more questions to clarify. Von Mutius however assumes that the findings from the study can be used in the prophylaxis of asthma in the foreseeable future. "Missing ideas, different people work on them," she says. For example, a research team in Finland studies how intestinal flora and the immune system change when subjects rub their hands with a defined soil mixture.
Up to 50 percent lower asthma risk
But there are already products like sprays for premises or probiotic foods for asthma prevention. "In my opinion, it's too early," says the scientist. "I wish these products were first tested in the tests." However, since probiotic foods and sprays are not needed for approval, such as drugs, they can simply be placed on the market. "It's profitable," von Mutius says. It has not been proven, but it is conceivable that they can lead to dangerous infections in people with impaired immune systems.
Roger Lauener also warns of wrong conclusions from the research. "We do not know how the protective effect works and which bacteria are right behind it," says the current study co-author and chief physician at a children's hospital in Eastern Switzerland. He strongly advised not to "dust the dust on the ground and not give it to the child," as he clearly mentions. Also, vaccination is still recommended without limitation.
The goal is to adequately prophylaxis
"Not every microorganism is healthy," says the pediatrician. "The research is now exciting and promising, but still premature for babies." Not only because there are other known risk factors for asthma, especially cigarette smoke, environmental pollutants such as soot and particles, physical inactivity and allergies. In addition, the role has inherited prediction.
However, various studies show, according to Lauener, that children from farms have 50 percent lower risk of developing asthma and allergies. When the mechanisms are clarified, appropriate measures would probably have a similar effect. This does not only apply to asthma, but also to allergies where it also affects the farm.
Nutrition factors also play a role
Lauener suspects that at least partially similar mechanisms are effective in asthma. "Various studies have shown that food factors also play an important protective role, such as certain short chain fatty acids," says Lauener, who is involved in such studies, among other things, with milk. He again warns that raw raw milk is not consumed. "Raw milk can contain germs that cause dangerous infections."
The discovery that peasant children are better in terms of allergies and asthma, by chance, is a Swiss discovery. He returns to the land of Dr. Markus Gassner from Grabs SG. He noted the difference between children in the 1980s as a school doctor. For a long time, experts have mistrusted the results and ignored them. It was all until the '90s, until a large study confirmed the findings. Since then, researchers around the world are seeking causes.
Created on: 20.06.2019, 15:26