Microbial environment, endocrine, immune system...

Disappointed by water and soil, who is the "disobedience"?

  Some people may experience symptoms such as gastrointestinal discomfort, vomiting, diarrhea, malaise, insomnia and many dreams once they leave their homeland and travel to other places. Many people use water and soil to explain these phenomena. Regarding the disobedience of water and soil, there is a record in "Biography of the Three Kingdoms, Wu Zhi and Zhou Yu", "If you are not accustomed to water and soil, you will suffer from diseases." "Song of Suolu" also mentioned, "The truth is far away, or you may not accept water and soil, medicine Self-healing." So, what exactly is it?

  "The argument of water and soil disobedience stems from our ancestors' observations. After living in another place, some people showed all kinds of discomfort in the body. When the environment changed back, the discomfort problem disappeared. The most common symptoms of water and soil discomfort are gastrointestinal discomfort, Loss of appetite, headache, poor sleep, allergic reactions, etc. Modern scientific research shows that due to changes in the environment, it further affects the physical and psychological state of the human body, bringing about the internal environment of the human body, especially endocrine, human microbial ecology, nervous system, Changes and adjustments in the immune system." Jiang Tao, senior engineer at the Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, said in an interview with a reporter from Science and Technology Daily.

  "From the moment of birth, except for the surface of the lungs, almost all parts of the air that can be reached, such as the surface of the skin, eyelids, respiratory tract, especially the nose and mouth cavity, gastrointestinal tract, and urogenital tract, will establish a microbial ecology. The result of interaction and mutual selection between the human body and microorganisms. In particular, the total number of gastrointestinal microorganisms is roughly on the order of human body cells, which directly affects human dietary preferences and digestive function." Jiang Tao said that the composition and interrelationship of these microorganisms are Formed in a long-term life, everyone is different, and it is related to their health status and diet. For example, people who are accustomed to a low-fiber diet have more anaerobic bacteria and fewer aerobic bacteria in the intestinal flora, and those who prefer a high-fiber diet The situation is exactly the opposite.

  "This is a dynamic adjustment mechanism. When the health status changes and different foods are eaten, the composition and interrelationship of microorganisms will change to some extent." Jiang Tao said that after going to a new place, the environmental microbial ecology has changed, plus Changes in diet have affected the original gut microbes, and the imbalance of the gut microecology may be responsible for the "water and soil" symptoms.

  In the study of the plasticity of intestinal flora, researchers at Huazhong University of Science and Technology uncovered the changes of intestinal flora in the process of the occurrence, development and recovery of symptoms of soil and water failure. Ning Kang, a professor at the School of Life Science and Technology, Huazhong University of Science and Technology, said that when a person arrives in a different place, he will not be accustomed to eating at first, and will produce various symptoms of inadaptation, but he can adapt to it after a while. , And can adapt again, this is the two-way plasticity of intestinal flora.

  The Ningkang research team recruited a team of 10 volunteers who set off from Beijing and stayed in Trinidad and Tobago for 6 months before returning to Beijing. Using a high-density longitudinal sampling strategy, the researchers collected stool samples from volunteers and recorded detailed information about their diets. Through high-throughput sequencing and related analysis of stool samples, the researchers discovered the dynamic changes of human intestinal flora due to dietary changes over a longer period of time.

  "Changes between intestinal flora of volunteers who conduct cross-border travel experiments are usually completed within 1 month." Ning Kang said that long-term changes in diet can change intestinal flora, and the restoration of diet can also make intestinal flora restore.

  The study found that the dynamic changes of volunteers' intestinal flora have a specific trend, which can be divided into two types, which may be related to volunteers' intestinal type. In terms of the composition of the intestinal flora, it was also found that the relative abundance of Pachyphyta and Bacteroides showed a strong elasticity on the time axis, and they were inversely correlated during this time, while Proteobacteria and Actinomyces The relative abundance of Bacillus phylum also shows a plasticity pattern.

  The study, by integrating volunteers’ dietary information, confirmed that bidirectional plasticity is largely regulated by diet. During their stay in the Republic of Trinidad and Tobago, volunteer team members consumed more Western food: fish and seafood, dairy products and refined grains, which is very different from their dietary habits in Beijing. The increased consumption of these foods is significantly related to changes in the structure of the gut microbial community.

  The research team said that the two-way plasticity model of the intestinal flora can be of guiding value for the clinical practice of intestinal microbiome-related diseases from two aspects: first, the study pointed out that the diagnosis of gastrointestinal diseases should consider dietary habits and possible To improve the accuracy of diagnosis. Second, research suggests that in clinical practice, such as fecal transplantation and antibiotic treatment, it should take longer to monitor the treatment effect, because the intestinal microflora is very flexible.

  In fact, the human body has a strong ability to adjust. "Of course, this adaptability will vary from person to person. This is the same as the susceptibility to diseases. Disapproval is also an obvious reaction for some people. The fundamental reason is the genetic diversity that exists in the population, especially the genetic diversity of the immune system. Sex. People who respond to changes in environmental factors in different degrees and in different ways are different." Jiang Tao said.

  Jiang Tao emphasized that full attention should be paid to the phenomenon of water and soil discomfort, especially allergic physical discomfort. Anti-allergy treatment should be performed immediately, and the cause of allergy should be identified and remembered. If you must return to the environment with allergens, It is necessary to prevent in advance, and multiple relapses of allergic reactions are likely to have serious consequences, such as asthma, etc., and you should not be careless.

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  The composition of intestinal flora depends mainly on diet and lifestyle

  A study published in the British journal Nature by scientists from the Weizmann Institute in Israel showed that the composition of human intestinal flora is mainly determined by diet and lifestyle, and genetic factors have little effect.

  Hundreds to thousands of bacteria live in the human gut, which plays an important role in metabolism, immunity, cardiovascular function, etc., and may even affect mood and behavior. There are obvious differences in the composition of the intestinal flora of different people. The scientific community previously believed that this was mainly determined by genetics, but new research shows that the difference caused by genetic factors only accounts for 2%.

  The research team analyzed the genome and gut microbiota data of about 1,000 Israelis, as well as their diet structure, lifestyle, and drug use. These people come from 7 different ethnic groups with similar living conditions. The results showed that the composition of intestinal flora was highly similar among people who had no blood relationship but lived under the same roof.

  The analysis also found that when predicting indicators such as blood sugar levels and obesity, taking into account the composition of the intestinal flora can greatly improve the accuracy of the prediction and is superior to models that only consider genetic and environmental factors.

  This new discovery means that when adjusting the intestinal flora to treat diseases and improve health indicators, a set of methods will be applied to the entire population with the same environment and lifestyle, without having to formulate a plan based on individual genomes.

  Our reporter Ma Aiping