The diversity of intestinal microflora has increased by 3 times
Half a thousand new bacteria were found in the intestine
Copper news based on EurekAlert materials! – Researchers discover new knowledge about our intestinesBiologists from the Technical University of Denmark, thanks to the principle of analysis of genetic data developed by them, have identified more than half a thousand previously unknown bacteria in the human intestinal microflora, as well as about 800 new bacteriophages.
Scientists are confident that a more complete understanding of the gut microbiome can significantly improve understanding of the nature of diseases such as type 2 diabetes, asthma, obesity and others, as well as help in the search for methods of their therapy. The work was published in the journal Nature Biotechnology (Nielsen et al., Identification and assembly of genomes and genetic elements in complex metagenomic samples without using reference genomes).
A common method of metagenomic analysis of bacterial communities is based on comparison with reference (average obtained during mass examination) genetic profiles. However, the species diversity of microorganisms significantly exceeds the reference values. To solve this problem, the authors developed a new principle of DNA sequencing data analysis, which they called the "co-abundance principle".
The method is based on the basic assumption that different DNA fragments of the same organism (jointly represented genetic groups, CAGs) are represented in the same volume in each individual metagenomic sample and this indicator varies in a series of samples. This principle makes it possible to "collect" the genomes of even previously unknown microorganisms in extremely complex microbial communities without resorting to the help of reference data.
The authors tested the method on 396 samples of intestinal microbiomes and identified almost seven and a half thousand CAGs. As a result, they managed to restore the genomes of more than 500 previously unknown intestinal bacteria. So far, the genomes of only 200-300 microorganisms living in the intestine have been sequenced.
In addition, scientists have found about 800 viruses attacking microorganisms – bacteriophages, also previously unknown. Currently, they are busy identifying their targets in order to make it possible to use them as antimicrobial agents alternative to antibiotics. In addition, the researchers focused on the study of joint interactions between intestinal bacteria, which could potentially enable the development of selective therapies for various diseases. "Ideally, we could add or remove a specific bacterium from the intestine and have a positive effect on the microflora in this way," says one of the authors of the study, Soren Brunak.
It is worth noting that in recent years there has been a lot of scientific data suggesting a key role of the composition of the intestinal microflora in the pathogenesis of various diseases. In particular, we are talking about Crohn's disease, autism, rheumatoid arthritis, multiple sclerosis.
Portal "Eternal youth" http://vechnayamolodost.ru08.07.2014