Scientists at Emory University in the United States have found that bacteria living in the human intestine release indoles, chemicals (C8H7N) that can prolong life and fight old age. Biologists came to this conclusion by testing the effect of these aromatic compounds on worms, flies and mice. The researchers' article was published in the journal Proceedings of the National Academy of Sciences.
It is known that the intestinal microflora supports the metabolism of macro- and microelements in the human body, strengthens the immune system and prevents the spread of pathogenic organisms. With age, the composition of bacteria in the gastrointestinal tract changes, which can impair quality of life. However, the mechanism through which microbes are linked to the aging process remained unknown.
As experimental organisms (biosensors), biologists used the free-living nematode Caenorhabditis elegans, the fruit fly Drosophila melanogaster, and rodents. The action of indole and some of its derivatives (indole-3-carboxaldehyde and heteroauxin) was tested on animals. These substances were secreted by the K12 strain of Escherichia coli, which was placed in the intestinal tract of organisms. The state of the latter was compared with age-related changes in biosensors, inside which E. coli lived, unable to synthesize indoles.
It turned out that K12 prolonged the life of nematodes, and also delayed the onset of senile weakness. The same was observed for fruit flies and mice.
To determine the mechanism of this action, scientists consistently turned off genes in C. elegans responsible for susceptibility to stress and regulation of life expectancy. It turned out that the action of indole in flies and worms is mediated through the aryl-hydrocarbon receptor (AHR), which transmits a signal from xenobiotics (substances foreign to the body) that bind to them into the cell. In senescent C. elegans, in response to the presence of indoles, it changes the activity of genes in such a way that their expression profile begins to resemble that of young animals.
Although people did not participate in the experiments, scientists believe that indoles, which have the same effect on animals from different groups, will act in the same way on the human body. The data obtained indicate the possibility of creating life-prolonging drugs based on substances secreted by the microflora.
