“This snapshot of how the virome interacts with gut microbiomes could tell us about how microbial and viral ecology evolves over the lifetime of a person,” said Ramnik Xavier, director of immunology and co-director of the infectious disease and microbiome program at the Broad Institute of MIT (Massachusetts Institute of Technology), in Cambridge, Mass.
"This offers an important starting point for uncovering the mechanisms behind how the gut ecosystem maintains health," Xavier said in a news release from the journal Nature Microbiology.
The virome is the collection of viruses in the gut, while the microbiome is the community of microorganisms.
Studying almost 200 people in Japan and Sardinia, researchers found that centenarians had a greater diversity of bacteria and viruses in their guts that could help protect them from infectious diseases. Their gut viruses increased the ability of the healthy gut bacteria to break down sulfate, which could help fight bacterial infections.
This adds to existing evidence that as bacteria, viruses and fungi in the gut interact, they also play an important role in preventing age-related conditions, the study authors explained.
Previously, a team led by Xavier found that intestinal bacteria in centenarians produced unusual bile acids that could help prevent infections.
Other researchers have found that viruses that infect bacteria have an effect on cognition (thinking) and memory in mice. But the role that the viruses play in the gut and aging in humans remains unknown, in part because viral DNA can be difficult to extract from complex samples.
For this study, the researchers applied a deep-learning based framework to analyze viral information from the DNA present in complex samples, such as stool.
The researchers compared viromes of young adults over 18, older adults over 60 and centenarians 100 and up from previously published datasets in Japan and Sardinia. Both places have unusually high numbers of centenarians.
The U.S. National Institutes of Health has more on the microbiome.
SOURCE: Nature Microbiology, May 15, 2023