Gut bacteria will help slow down aging
Researchers at Baylor College of Medicine and the University of Texas, working under the guidance of Associate Professor Meng Wang, identified bacterial genes and compounds synthesized by bacteria that can increase life expectancy and slow the progression of tumors, as well as the accumulation of beta-amyloid associated with Alzheimer's disease in nematodes Caenorhabditis elegans.
According to Dr. Wang, scientists are getting more and more evidence that the interaction of an organism with millions of microorganisms inhabiting it can affect its functions, including cognitive and metabolic activity, as well as aging processes. The aim of the work carried out by the authors was to study the supposed role of the genetic profile of the microbiome in longevity.
For technical reasons, this question is very difficult to study in mammals, so the researchers used C.elegans roundworms as a model, which are transparent simple organisms the size of a pinhead, whose genome is in many ways similar to the human genome. During the 2-3-week life cycle, these worms feed on bacteria, grow into an adult, multiply and progressively age, losing strength and health, and die. Many laboratories use C.elegans as a model for studying fundamental biological processes.
To study the effect of individual bacterial genes on the lifespan of C.elegans, the authors used a complete library of deletions (deletions) of Escherichia coli coli genes – a collection of strains, each of which is a carrier of a deletion of one of almost 4,000 genes.
They fed the worms bacteria of mutant strains and then estimated their life expectancy. As a result, it turned out that for almost 4,000 bacterial genes tested, deletions of 29 genes had a positive effect on the longevity of worms. At the same time, 12 of them also protected C.elegans from the development of tumors and the accumulation of beta-amyloid, characteristic of Alzheimer's disease in humans.
Further experiments showed that eating certain mutant strains of E. coli increased the lifespan of nematodes by affecting a number of previously studied processes associated with the aging of these organisms. Other mutants contributed to longevity due to increased production of colanic acid, a polysaccharide that makes up the protective capsule of bacteria. Adding purified colanic acid to the worms' food also increased their lifespan. Colanic acid had a similar effect when added to the feed of laboratory fruit flies, as well as in the culture medium of human cells.
A drawing from an article in Cell.
The researchers suggest that in the future, the data they have obtained will form the basis for the development of drugs to slow down the aging process based on bacteria or their components.
It is also interesting that they established the fact that colanic acid regulates the dynamics of the processes of fusion and division of mitochondria – intracellular structures that are the energy centers of the cell.
These observations are interesting from a biological point of view, as they can help to understand the interactions between microorganisms and their hosts. There is a hypothesis that mitochondria appeared as a result of the evolution of bacteria that penetrated into primitive cells millions of years ago. The data obtained by the authors indicate that bacteria still influence the interaction of mitochondria inside the cells of living organisms. Apparently, this type of interaction is very important, and its detailed understanding will help to understand the deep relationships between bacteria and the organisms with which they coexist.
Article by Bing Han et al. Microbial Genetic Composition Tunes Host Longevity is published in the journal Cell.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of Baylor College of Medicine: Gut bacteria might one day help slow down aging process.
16.06.2017