Brisbane: A study published in Nature Microbiology has identified 54,118 species of viruses living in the human gut, 92 percent of which were previously thought to be unknown. Our colleagues from the Joint Genome Institute in California and Stanford University found that most of these species are bacterial scavengers. These viruses “eat” bacteria but cannot attack human cells.
When most of us hear the name of a virus, we start thinking of the organisms that infect our cells with diseases like mumps, measles, or the current COVID-19. There are a large number of these microscopic parasites in our body and especially in the stomach which target the microbes found in them.
Recently there has been a great interest in learning about the microbiome that lives in our gut. These micro-organisms not only help us to digest food but many of them have a very important role. They protect us from pathogenic bacteria, regulate our mental health, strengthen our immune system as a child, and play an ongoing role in immune regulation as we mature.
It is fair to say that the human gut is now the most well-studied microbial ecosystem on the planet. Yet more than 70 percent of the microbe species found in it have not yet been grown in the laboratory. In our new research, we and our colleagues computationally isolated viral sequences from metagenomes—feces samples were taken from people from 24 different countries. We wanted to get an idea of the extent to which viruses have made their way into human feces.
This effort resulted in the creation of the Metagenomic Gut Virus Catalog, the largest resource of its kind to date. This catalog contains information on 189,680 viral genomes that represent more than 50,000 distinct viral species.
Remarkably, more than 90% of these viral species are new to science. They collectively encode over 450,000 different proteins. We also studied different virus subspecies and found some startling patterns in the 24 countries included in the study.
