We have been taught to be a clean and loving boy since childhood, but when we grow up, the rules of this world have changed again. Many people love clean people, but in an excessively clean environment, it is easy to breed various diseases. And some people who are not so demanding of the environment and themselves can adapt better. What happened? Research tells us that sometimes being dirty will make you healthier.
In a sense, cleanliness is health, and hygiene is cleanliness.
The latest research shows that dirt can make organisms more resistant.
Blessed are the lazy and untidy. In the face of the criticism of cleanliness addicts, we can confidently say that dirty is healthier.
This is based on science. DeniseKelly, an intestinal immunologist at the University of Aberdeen, found that there is a direct relationship between dirty living environment, immune health and gene expression. If piglets grow freely outdoors since childhood, they will get beneficial bacteria in their later life and get along well with bacteria and viruses, thus obtaining the best immunity.
Be a free pig
The researchers selected 54 piglets and randomly divided them into three groups. One group lives freely outdoors, the other group is kept in captivity, and the other group is injected with antibiotics every day to make them live in a completely isolated environment. Then, the researchers killed the piglets on the 5th day (newborn), 28th day (weaning) and 56th day (near maturity) to study their intestinal tissues and feces.
These three groups of piglets have different lifestyles and different appearances. Piglets who live freely outdoors look dirty and ugly because they are in contact with nature and roll in the mud. The last two groups of pigs kept indoors were fat and clean in vain. Of course, the difference in appearance will also reflect the difference in internal conditions of the body. Contrary to the traditional view that cleanliness is health, dirty pigs that grow freely outdoors have better immunity.
The researchers found that 90% of the bacteria in the intestines of piglets raised outdoors are thick-walled fungi, most of which are lactobacillus. This kind of bacteria is good for health. They can make piglets have the ability to inhibit intestinal pathogenic bacteria, such as Escherichia coli and Salmonella. In contrast, in the intestinal flora of pigs raised indoors and completely isolated from the outside world with antibiotics, scleroderma is less than 70% and more than 50% respectively. At the same time, the proportion of bacteria from lactobacillus in the latter two groups of piglets is also small. Therefore, it can be seen from the types of bacteria in the intestine that piglets growing freely outdoors have higher immunity and stronger disease resistance.
Moreover, different microbial populations in the intestine of piglets will also affect the gene expression related to the immune system of piglets. Piglets growing in isolated environment express more genes involved in inflammatory immune response and cholesterol synthesis, but piglets growing freely outdoors have more genes related to immune T cells. Although it is difficult to judge the mechanism of inflammatory immune response and cholesterol gene expression and whether it is good or bad for the body, the increase of T cell-related gene expression shows that it is a manifestation of immune enhancement, because T cells are the main immune cells of mammals including humans and perform cellular immune functions. Therefore, if this immune mechanism of pigs is applied to humans, it may reduce future allergies and other autoimmune diseases by interfering with intestinal bacteria in early childhood.
GlennGibson, a food microbiologist at the University of Reading in the UK, believes that this is a direct argument to prove the relationship between living environment and immune response, while previous studies are only indirect inferences. This shows that the immune response is indeed related to microorganisms in the intestine. At the same time, researchers at the University of Aberdeen have now taken a step forward, because this study shows that gene expression is consistent with immune response. However, since the research is carried out on pigs, it cannot be said that the same conclusion can be drawn on people.
If you pay too much attention, you will get a civilized disease.
In fact, many previous studies have proved that a dirty environment can actually enhance immunity. For example, mice that survive tenaciously in sewers and farms have a healthier immune system and are less prone to allergies and illness than their carefree counterparts who live in comfortable sterile laboratories. A study on allergic diseases of 1246 children by Arizona researchers in the United States shows that the probability of asthma can be greatly reduced if babies often contact with other children in the first six months of their lives. Moreover, compared with babies who stay at home and have little contact with other children, babies who are taken care of by nurseries or caregivers are much less likely to develop asthma.
There are more research results to illustrate the problem. In today's society, asthma, pollinosis and allergic dermatitis are called civilized diseases, which develop fastest in Japan and West Germany. The historical comparison is very interesting. Different from West Germany, the incidence of this civilized disease in East Germany is much lower than that in West Germany. After investigation, it was found that because the sanitary conditions in East Germany were not as good as those in the former West Germany and the environmental pollution was worse than that in Sidegard, the infection rate of parasites such as ascaris lumbricoides was high among children in East Germany, and as a result, the immunoglobulin E value in their bodies also increased, thus inhibiting diseases such as asthma, hay fever and allergic dermatitis.
In addition, the results of animal experiments are even more worrying. Mice infected with ascaris lumbricoides twice and mice not infected with ascaris lumbricoides were infected with malaria, the former all survived and the latter all died. In other words, parasites can not only prevent organisms from being allergic, but also provide resistance to plasmodium. These situations show that people need to be in full contact with nature. We can't lock ourselves up because there are pathogenic bacteria and parasites, or kill all microorganisms and parasites, because they are indispensable elements to enhance our own immunity.
However, the problem now is that if the concepts of cleanliness and filth are to be applied to people, parents and educators obviously have different requirements for their children. For example, children in rural areas and children in cities have different requirements for cleanliness because of different opportunities and time to get in touch with nature. Children in rural areas will be dirtier and children in cities will be cleaner, but the immunity of the former is definitely stronger than that of the latter. Therefore, scientists and educators need to draw a line between children and nature, and should accept the view that children may be better if they are a little dirty, because this will help enhance their inherent natural immunity.