Scientists Identify More Than 140,000 Virus Species In The Human Intestine

Viruses that inhabit the intestine are called bacteriophages, which may infect bacteria. This could impact the intestinal microbiome imbalance, contributing to diseases and conditions such as obesity, inflammatory bowel disease, and allergies.

Researchers at the Wellcome Sanger Institute and the European Molecular Biology Laboratory (EMBL-EBI) have identified over 140,000 viral species living in the human intestine, more than half of which have never been seen before.

The research was published in the journal Cell.

Although it may make you feel wriggly, your intestines are full of life. Millions of tiny bacteria and viruses call the intestines home, with different species struggling for the wealth of nutrients that exist there. Most of these species are extremely beneficial to your health, and there is a constant link between mental and physical health.

According to the authors of the study, the number and variety of viruses found in more than 28,000 intestinal microbiome samples collected from different parts of the world are surprisingly high.

In this study, researchers used a DNA sequencing method called metagenomics, which explored and cataloged the biodiversity of viral species found in 28,060 public human gut metagenomes and 2,898 bacterial isolate genomes cultured from the human gut. The analysis identified more than 140,000 viral species in the human intestine.

According to Dr. Alexandre Almeida, Postdoctoral Fellow at EMBL-EBI and the Wellcome Sanger Institute, "It is important to remember that not all viruses are harmful, but they are an integral part of the intestinal ecosystem. For one thing, most of the viruses we found have DNA as their genetic material, which is different from the pathogens most people know, such as SARS-CoV-2 or Zika, which are RNA viruses. Secondly, these samples came primarily from healthy individuals who did not share any specific diseases. It's fascinating to see how many unknown species live in our intestines and to try and unravel the link between them and human health."

Among the tens of thousands of viruses discovered, a new clade (a group formed by a phylogenetic branch made up of a species and all its descendants) of high prevalence, known as Gubaphage, was identified as the second most prevalent group of viruses in the human intestine after the crassphage that was discovered in 2014.

According to the senior author Trevor Lawley, also from the Wellcome Sanger Institute, "Bacteriophage research is currently experiencing a renaissance. This high-quality, large-scale catalog of human gut viruses comes at the right time to serve as a blueprint to guide ecological and evolutionary analysis in future virome studies."