Researchers from San Diego State University and elsewhere uncovered a novel virus lurking within published human fecal metagenomes.
As they report in Nature Communications, SDSU's Robert Edwards and colleagues uncovered a bacteriophage they dubbed crAssphage whose 97 kilobase pair-long genome is six times as common in publicly available metagenomes as all other known phages combined. In virus-like particle-derived metagenomes and total community metagenomes, it makes up to 90 percent and 22 percent of all reads, respectively, they add.
It's in, notes Ed Yong at Not Exactly Rocket Science, some 75 percent of the more than 450 published metagenomes and found in people from the US, Europe, and South Korea.
Based on a co-occurrence profiling approach the researchers developed, they say the phage likely infects the Bacteroides that live within the human gut.
"We suspect this virus is very important in regulating the number of these bacteria [the Bacteroides] in the intestine," Edwards tells NPR's Goats and Soda.
Bacteroides "are major players in our guts," Yong says, adding that they aid in the breakdown of food, the development of the immune system, and the protection of the host from disease-causing bacteria.
"Given the virus's abundance and how widespread it is, it is probably going to be very important for understanding the ecology of the human gut," adds the University of California, Davis' Jonathan Eisen to NPR.