Following the analysis of human feces, scientists identified 54,118 types of viruses, most of which turned out to be bacterial viruses \u2013 bacteriophages<\/p>\n
Recently, there has been growing interest among scientists in the human microbiota \u2013 microorganisms that live on our skin and mucous membranes and have a significant impact on our health. Perhaps the largest amount of symbiotic flora lives in the human gut: it is involved in food digestion, protection against pathogens, maturation of the immune system and modulation of its activity, and even influences higher nervous activity. <\/p>\n
Today, the human gut microbiota is the most thoroughly studied microbial ecosystem in the world, although more than 70% of bacterial species have not yet been cultured in the laboratory. This is known thanks to the use of metagenomics methods \u2013 genetic analysis of material obtained from a specific environment. The sequence of the entire DNA of such material provides an instant “snapshot” of all living organisms that appeared in the sample at a given time. Metagenomics has shown how far modern science is from identifying and isolating all gut bacteria, and even further from understanding gut viruses. <\/p>\n
Scientists used computer programs to analyze 11,810 metagenomes from stool samples of people from 24 countries *. Their goal was to determine what proportion of the genomes of gut inhabitants are viruses. The result of the study was the creation of the Metagenomic Gut Virus Catalog, which is to date the most comprehensive resource of its kind. The catalog contains 189,680 viral genomes, representing more than 50,000 virus species. Interestingly, more than 90% of them are unknown to science. Together, they encode more than 450 thousand different proteins that can be beneficial or harmful to bacteria and, accordingly, can have one or another effect on humans. <\/p>\n
The most common genetic elements in the analyzed phage genomes are the so-called Diversity-Generating Retroelements (DGRs). They cause mutations in specific target genes to create as many variants as possible for the constant selection of optimal ones in the evolutionary race with host bacteria. <\/p>\n
After identification, the phages had to be associated with their host bacteria. To do this, scientists utilized the functions of the CRISPR system \u2013 a type of bacterial immune system that “remembers” viral infections and prevents their recurrence. Bacteria copy and store fragments of viral genes in their own genome to recognize and destroy the virus in the event of a new invasion. These copies can identify which phages are the host bacteria in the gut ecosystem. <\/p>\n
Naturally, the most common virus species in the gut were associated with the most common bacterial species in this ecosystem \u2013 mainly representatives of the Firmicutes and Bacteroidota phyla.<\/p>\n
What is the benefit of gut virus research? A very promising area of application for the information gained is phage therapy, namely the targeted influence of the human microbiota with the help of bacteriophages. While diet, antibiotics, probiotics, prebiotics, and other modern approaches have a general, non-specific effect on the microbiota, phage therapy can offer subtle modulation of its composition. For example, phages can be an effective treatment for Clostridioides difficile infection, which primarily develops as a result of long-term antibiotic therapy. <\/p>\n
Although the authors already have a wealth of information about viruses that are components of the normal human gut microbiota, they admit that they have only “gotten to know” a small part of this vast “universe” and there is still a long way to go to get a complete picture.<\/p>\n
* Nayfach S, P\u00e1ez-Espino D, Call L et al. Metagenomic compendium of 189,680 DNA viruses from the human gut microbiome. Nat. Microbiol, 2021; 6: 960-970. https:\/\/doi.org\/10.1038\/s41564-021-00928-6<\/p>\n","protected":false},"excerpt":{"rendered":"
Following the analysis of human feces, scientists identified 54,118 types of viruses, most of which turned out to be bacterial viruses \u2013 bacteriophages Recently, there has been growing interest among scientists in the human microbiota \u2013 microorganisms that live on our skin and mucous membranes and have a significant impact on our health. Perhaps the […]<\/p>\n","protected":false},"author":1,"featured_media":8676,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_bbp_topic_count":0,"_bbp_reply_count":0,"_bbp_total_topic_count":0,"_bbp_total_reply_count":0,"_bbp_voice_count":0,"_bbp_anonymous_reply_count":0,"_bbp_topic_count_hidden":0,"_bbp_reply_count_hidden":0,"_bbp_forum_subforum_count":0,"footnotes":""},"categories":[],"tags":[],"class_list":["post-8675","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry"],"jetpack_featured_media_url":"https:\/\/www.phage.help\/wp-content\/uploads\/2021\/07\/darm.jpg","_links":{"self":[{"href":"https:\/\/www.phage.help\/en\/wp-json\/wp\/v2\/posts\/8675","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.phage.help\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.phage.help\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.phage.help\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.phage.help\/en\/wp-json\/wp\/v2\/comments?post=8675"}],"version-history":[{"count":0,"href":"https:\/\/www.phage.help\/en\/wp-json\/wp\/v2\/posts\/8675\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.phage.help\/en\/wp-json\/wp\/v2\/media\/8676"}],"wp:attachment":[{"href":"https:\/\/www.phage.help\/en\/wp-json\/wp\/v2\/media?parent=8675"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.phage.help\/en\/wp-json\/wp\/v2\/categories?post=8675"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.phage.help\/en\/wp-json\/wp\/v2\/tags?post=8675"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}