Gut microbes as a health hazard
How potentially pathogenic bacteria can be present in humans as part of the intestinal flora for decades without negatively affecting health has long been a medical mystery. The latest research results now show that the intestinal bacteria change over time evolve and become more pathogenic can become.
In a new study, experts from the internationally highly regarded Yale Universitywhich key factors determine the so-called bacterial translocation, through which Intestinal bacteria overcome the intestinal barrier be able. The results were published in the journal “Nature” released.
Diseases caused by gut microbes
gut microbes can promote health or endanger it by contributing to the development of certain diseases. These include, for example, autoimmune diseases, inflammatory bowel diseases, the metabolic syndrome and even neuropsychiatric disorders.
Sick from chronic inflammatory response
A common explanation for the negative effects of intestinal bacteria is the so-called Leaky-Gut-Hypothese. This assumes that potentially harmful bacteria are able to escape from the gut. Then solve one chronic inflammatory response which can promote many different diseases.
Bacteria can overcome the intestinal barrier
Gut bacteria can gain the ability to cross the gut barrier and organs outside of the intestine to persist, causing them chronic inflammation and related diseases, explains study author Dr. Noah Palm of the Yale University in a press release.
„A mystery, however, is how potentially pathogenic bacteria can exist in healthy people for decades without any apparent health consequences‘ the author of the study continued.
Microbes split into two populations
The team analyzed the genetics and behavior of a species of potentially pathogenic bacteria. These were in germ-free mice without their own gut microbes introduced. So it turned out that the microbes gradually in two different populations split up.
Mutation enables survival outside the gut
One of these populations behaved similar to the original tribe. The other populations evolved tiny DNA mutationswhich enabled the bacteria to survive in the intestinal mucosa.
In addition, the bacteria were also able to survive in the lymph nodes and liver after leaving the gut, the researchers said.
Protection from the immune system
Conventional pathogens are from the immune system eliminated quickly. On the other hand, the small colonies of bacteria that have migrated remain hidden in the organs, which means they are at least temporarily hidden from the environment immune system can evade.
The specialists noted that the presence of these bacteria inflammatory pathologies such as autoimmune diseases can trigger. This phenomenon could at least partially explain why some people with potentially pathogenic bacteria do not get sick, and why they do Risk of disease increases with ageaccording to the researchers.
The ability of gut bacteria to become more pathogenic is made possible by a phenomenon known as the team, according to the team Evolution within the host referred to as. It explains why individual types of bacteria that occur in the human intestine change over the course of life adapt and develop be able.
Experts conclude that influencing the pace and course of evolution environmental factors also have important implications for the development of diseases through microbiota.
Eating a healthy diet leads to a variety of bacteria in the gut
People who are mostly eat healthydevelop more diverse bacterial communities in the gut and this means that many different microbes have to compete for space and resources, the researchers explain. This limits the population size of each individual species.
The population limitation means that the risk for the development of potentially unhealthy variants reduced, which can escape from the intestine. On the other hand, more bacteria can grow in less diverse bacterial communities niches in the gut to open. This increases the likelihood that harmful bacterial variants will develop, explains Dr. palm.
„These bacteria are essentially primed to exist in organs outside of the gut. We believe that this evolutionary process starts all over again with each new host, since non-pathogenic strains are preferentially transmitted from person to person‘ adds the doctor.
Development of new therapies in prospect
The improved understanding of how evolution within the host affects bacterial properties in the gut could also lead to new therapeutic approaches fight diseases related to bacteria escaping from the gut, the research team hopes. (as)
Author and source information
This text corresponds to the specifications of medical specialist literature, medical guidelines and current studies and has been checked by medical professionals.
Sources:
- Yi Yang, Mytien Nguyen, Varnica Khetrapal, Nicole D. Sonnert, Anjelica L. Martin, et al.: Within-host evolution of a gut pathobiont facilitates liver translocation; in: Nature (veröffentlicht 13.07.2022), Nature
- Yale University: How gut microbes can evolve and become dangerous (veröffentlicht 13.07.2022), Yale University
Important NOTE:
This article contains general advice only and should not be used for self-diagnosis or treatment. He can not substitute a visit at the doctor.