July 26, 2014 - A virus
that lives in the human gut has just been discovered, and to the surprise of scientists, it can be found in about half the world's population, according to a new study.
While it's not yet clear exactly what the virus does, scientists are eager to find out whether it promotes health or influences susceptibility to certain conditions, said Robert Edwards, a bioinformatics professor at San Diego State University
and one of the researchers who worked on the study.
The researchers first uncovered hints of the virus after analyzing DNA
from fecal samples of 12 people. They found a cluster of viral DNA
that all the samples had in common, Edwards
Next, the researchers searched a large database of genetic sequences in samples taken from people living on several different continents, looking for the virus's DNA
sequence, and found the virus in 75 percent of samples of human feces. However, some of these samples were from the same person, Edwards said, so after taking this into account, the researchers estimated that the virus is present in about half of all people. [5 Ways Gut Bacteria Affect Your Health]
But how could such a common virus go unnoticed for so long? One of the reasons may be that previously, most researchers compared DNA
from current samples only to DNA
sequences already known to exist, Edwards said. But in the new study, the researchers first compared the DNA
in their samples to one another, looking for common sequences.