Research results that intestinal bacteria may evolve to live in places other than the intestine

The bacteria that inhabit the inside of the intestine are called

enterobacteria , and in recent years, attention has been paid to the state and diversity of intestinal bacteria that are involved in people's health. Research results have been announced that such intestinal bacteria 'may evolve to live in places other than the intestine.'

Within-host evolution of a gut pathobiont facilitates liver translocation | Nature

How gut microbes can evolve and become dangerous | YaleNews

Gut Bacteria Could Be Evolving Inside Us to Escape The Intestine : ScienceAlert

Various studies have been conducted on the effects of intestinal bacteria on human health, and it is said that intestinal bacteria also affect diseases such as chronic inflammation, weight gain, and depression. Although there are many unclear points about the mechanism by which intestinal bacteria affect health, one of the hypotheses is that the intestinal mucosa becomes thin and undigested and waste matter leaks out of the intestine due to leaky gut syndrome . There is something that causes intestinal bacteria to flow out and cause chronic inflammation that leads to various diseases.

'But the idea that potentially pathogenic bacteria can live in healthy people for decades and not affect health,' said Noah Palm , an associate professor of immunobiology at Yale University. It was a mystery,' he said. Therefore, Palm et al.'s research team conducted research to monitor how intestinal bacteria evolve over time.

The research team introduced Enterococcus gallinarum , a type of pathogenic enterococcus that is found in about 6% of the human gut microbiota, to germ-free mice that do not have intestinal microbes. We conducted a monitoring experiment.

As a result of the experiment, we observed that Enterococcus gallinarum evolved into two different types in the gut of mice. One type was similar to the original strain, but the other type was able to live in the intestinal mucosa due to DNA mutations, and it escaped the intestines and survived in the lymph nodes and liver. It was evolving like

Mutated bacteria can hide in organs, at least temporarily avoiding immune system attack. The presence of such bacteria may, over time, cause inflammation associated with autoimmune diseases, the researchers note.

This evolutionary process is a phenomenon called ``intra-host evolution,'' and since non-pathogenic bacteria are preferentially transferred between individuals, it is believed that evolution will be redone for each new host. Diversity in gut microbiota reduces populations due to the limited resources available to individual bacteria, and reduces the likelihood of emergence of dangerously mutated pathogens. However, when the diversity of gut bacteria is low, pathogens with dangerous mutations are more likely to emerge, Palm explained.

in Science,   Creature, Posted by log1h_ik