- Researchers examined the microbiomes of centenarians from Japan and Sardinia.
- They found that centenarians have more diverse bacteria and viruses in their gut than their younger counterparts.
- The findings indicate that improving gut bacteria and virus diversity could increase healthy longevity.
Research also suggests that the gut microbiome plays a crucial role in the aging process. For example,
While gut bacteria are well known for their influence on overall health, fewer
Some studies show that viruses known as bacteriophages bind to bacteria in the gut, and affect their activity. In some cases, they may improve bacterial function by
As centenarians have decreased susceptibility to age-related diseases and infections compared to younger individuals, understanding more about what makes their microbiomes unique could aid the development of strategies that promote healthy aging.
Recently, researchers compared the gut virome of Japanese centenarians with that of younger adults aged 18 years and over, and older adults aged 60 years and over.
They found that centenarians had more diverse viromes than younger people in the study. The study was published in
Dr. J. Wes Ulm, a bioinformatic scientific resource analyst, and biomedical data specialist at the National Institutes of Health, not involved in the study, told Medical News Today:
“Remarkably, it was found that many of the centenarians actually had a much more effectively health-promoting microbiome and virome status than some younger subjects. And when this symbiosis is more effective, the body is able to greatly amplify its capacity to cleanse and renew itself. More mechanistically-focused studies are currently in development.”
For the study, the researchers gathered stool sample data from Japanese and Sardinian studies, including 195 centenarians, 133 older adults, and 61 young adults.
They used a virome discovery approach to identify viruses in the sample data. Altogether, they identified 4,422 viruses, including 1,746 that were previously undescribed.
After further analysis, they found that centenarians had more diverse gut bacteria and viromes than their younger counterparts. They also had higher levels of gut bacteria and viruses.
“We found great biological diversity in both bacteria and bacterial viruses in the centenarians. High microbial diversity is usually associated with a healthy gut microbiome. And we expect people with a healthy gut microbiome to be better protected against aging-related diseases,” says Dr. Joachim Johansen, postdoctoral researcher at the University of Copenhagen’s Novo Nordisk Foundation Center for Protein Research in Denmark, first author of the study, in a press release.
Infants tend to have high levels of actively replicating viruses that soon become dormant as they transition into adulthood. However, the researchers found that centenarians had higher levels of actively replicating viruses than younger adults — although not quite as many as infants.
The increased virome activity and diversity in centenarian microbiomes, noted the researchers, went on to boost the metabolic capacity of bacteria, which is linked to health benefits.
They noted, for example, that higher sulfur metabolism — as seen in the centenarians — is
“We have learned that if a virus pays a bacterium a visit, it may actually strengthen the bacterium. The viruses we found in the healthy Japanese centenarians contained extra genes that could boost the bacteria. We learned that they were able to boost the transformation of specific molecules in the intestines, which might serve to stabilize the intestinal flora and counteract inflammation,” says Dr. Johansen.
Dr. Ulm noted that a diverse gut virome enhances the detoxification functions of gut bacteria. He said: “The subject cohorts with a broader range of phage strains and variants seemed better-equipped at undertaking a wider gamut of biochemical processing, for instance, in achieving key steps in sulfate metabolism.”
“There are other factors at play, for example, the bacteriophages were [better at increasing biochemical processing] when they switched from a so-called lysogenic to a lytic state. But the sheer range of phage diversity no doubt plays a role [too],” he added.
Dr. Ulm noted that the findings demonstrate the relationship between the gastrointestinal tract and the human liver, which removes toxic metabolic byproducts from our bodies via a complex array of systems.
“Though it’s not something we’re generally aware of, our bodies are essentially symbiotes — maintaining a mutually beneficial relationship with a vast ecosystem of bacteria and [viruses] in our intestinal tract. Our [gastrointestinal] tracts provide a home for them, and they assist our [gastrointestinal] tracts by [helping neutralize] substances that might [harm our bodies],” he added.
MNT also spoke with Dr. Ulm about the study’s limitations. He noted that one limitation is that the study provided little information about what gave rise to the healthful microflora and viromes in the study.
Information such as what diets led to the observed results, for example, is missing.
“The study also, necessarily, can provide relatively little insight into the actual biochemical and molecular mechanisms through which the salutary microbiome and virome appear to be exerting their beneficial effects,” he added.
Dr. Simon Rasmussen, associate professor at Novo Nordisk Foundation Center for Protein Research at the University of Copenhagen in Denmark, one of the study’s authors, notes in a press release:
“If you discover bacteria and viruses that have a positive effect on the human intestinal flora, the obvious next step is to find out whether only some or all of us have them. If we are able to get these bacteria and their viruses to move in with the people who do not have them, more people could benefit from them.”
“Intestinal bacteria are a natural part of the human body and of our natural environment. And the crazy thing is that we can actually change the composition of intestinal bacteria. We cannot change the genes — at least not for a long time to come. If we know why viruses and intestinal bacteria are a good match, it will be a lot easier for us to change something that actually affects our health,” he concludes.
Read the full article here