Gut Microbiomes of Japanese Centenarians Offer New Insights Into Healthy Aging

A new study published in Nature Microbiology has uncovered a unique combination of gut bacteria and viruses in healthy Japanese centenarians, illustrating the impact of our gut microbiome on our health as we age.

The microbiome and aging

The gut microbiome – billions of bacteria, viruses and fungi that live in the intestines – plays many roles in human health. Studies have linked our gut microbiome to Alzheimer’s disease, endometriosis and even arthritis.

With a rapidly aging global population, a lot of focus is placed on healthy aging. Recently, a new study has investigated the gut microbiomes of Japanese centenarians and has identified a unique combination of intestinal bacteria and bacterial viruses.

“We are always eager to find out why some people live extremely long lives,” says Dr. Joachim Johansen, first author of the new study. “Previous research has shown that the intestinal bacteria of old Japanese citizens produce brand new molecules that make them resistant to pathogenic – that is, disease-promoting – microorganisms. And if their intestines are better protected against infection, well, then that is probably one of the things that cause them to live longer than others.”

Studying the virome

The study characterized the viral component of the gut microbiome – known as the virome – of centenarians and compared the diversity of viral species present with the viromes of young adults and adults in middle age.

The results of the study also show that the bacteriophage and bacterial communities in the microbiomes of centenarians have a greater potential for metabolizing sulfate, which may support resistance to pathogens.

A diverse microbiome

As well as a diverse virome, the centenarians also had a diverse overall microbiome, which the researcher mapped using an algorithm.

“High microbial diversity is usually associated with a healthy gut microbiome, and we expect people with a healthy microbiome to be better protected against aging-related disease,” says Johansen.

By mapping the microbiome, the researchers hope to characterize and understand the dynamics of the intestinal flora. In understanding the connections between viruses and bacteria in a microbiome that supports longevity, it may be possible to engineer the gut microbiome of other people to contribute to healthy aging and a longer lifespan.

“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,” explains Dr. Simon Rasmussen, associate professor and last author of the new study.

Insights into the interplay between bacteria and viruses

The new study has provided new insights into how the interactions between the bacteria and viruses in the gut may affect overall health.

“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 Johansen.

“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,” adds Rasmussen.

Reference: Johansen J, Atarashi K, Arai Y, et al. Centenarians have a diverse gut virome with the potential to modulate metabolism and promote healthy lifespan. Nat Microbiol. 2023;8(6):1064–1078. doi: 10.1038/s41564-023-01370-6

This article is a rework of a press release issued by the University of Copenhagen. Material has been edited for length and content.