What is already known
As people age, their gut microbiota becomes less diverse than that of younger individuals, with fewer beneficial bacteria and more opportunistic pathogens. Although previous studies suggested that the microbiota changes associated with ageing can influence a person’s health, little is known about the relationship between gut microbes and longevity.
What this research adds
Researchers studied the gut microbiotas of more than 1,500 people aged 20 to 117, including 297 centenarians. Compared to other old adults, centenarians have a gut microbiota that resembles that of younger individuals. The microbiota of centenarians is enriched in beneficial bacteria and has lower levels of harmless microbes that can become pathogenic under certain circumstances.
Conclusions
The findings suggest that longevity is associated with a specific microbiota signature that may have positive effects on older adults’ health by counteracting senescence or chronic diseases that generally accompany aging.
Scientists have long studied people who live to be 100 or more years in an attempt to define attributes that may promote longevity. Now, a study shows that the gut microbiota of centenarians resembles that of younger individuals and is populated by beneficial bacteria.
The findings, published in Nature Aging, suggest that longevity is associated with a specific microbiota signature that may have positive effects on older adults’ health by counteracting senescence or chronic diseases that generally accompany aging.
Researchers have known that as people age, their gut microbiota becomes less diverse than that of younger individuals, with fewer beneficial bacteria and more opportunistic pathogens. Although previous studies suggested that the microbiota changes associated with ageing can influence a person’s health, little is known about the relationship between gut microbes and longevity.
To address this question, researchers led by Weifei Luo at AIage Life Science and Shuai Wang at Guangxi Academy of Sciences studied the gut microbiotas of 1,575 people aged 20 to 117.
Youthful microbiota
Study participants were divided in five age-related groups and included 297 people aged 100 or older. A smaller group of 45 centenarians was tested twice over a year and a half. All the participants resided in Guangxi, China.
The researchers found that compared to other old adults, centenarians have a gut microbiota that resembles that of younger individuals. Long-lived individuals showed a unique microbiota signature, with an overrepresentation of Bacteroides species, including B. thetaiotaomicron, B. ovatus, B. uniformis, B. stercoris, B. fragilis and B. salyersiae.
The microbiota of centenarians was also enriched in beneficial Bacteroidetes bacteria, whereas Firmicutes, including Clostridiales, Ruminococcaceae and Faecalibacterium, were enriched in other old adults.
Long-lasting hallmarks
The team found that gut bacteria with potential harmful or inflammatory roles, such as Klebsiella, Streptococcus, Enterobacter and Rhodococcus, were more common in old adults than in centenarians or young adults. “The low abundance of microorganisms with pathogenic potential in centenarians and young people supports the notion that increased colonization by potential pathobionts is associated with aging and might occur only in old adults,” the researchers say.
The analysis also revealed that a decrease in microbial diversity is associated only with old adults but not with centenarians.
All these microbiota hallmarks were maintained in centenarians throughout aging, the researchers found.
“Our results suggest that the gut microbial community in centenarians is associated with longevity and characterized by ‘youth’-associated signatures with high species diversity, a low abundance of potential inflammatory bacteria and a high level of bacteria with beneficial potential in the gut,” the authors say.
