Centenarians: does the secret of their longevity lie in the gut microbiota?

Our bodies change throughout our lives. This includes our gut microbiota, to the extent that the species that make it up can pinpoint our age. We know that the gut microbiota changes with age, losing diversity, and ultimately becoming unbalanced (dysbiosis), which may in turn contribute to the aging process. Conversely, maintaining a balanced microbiota may preserve the proper functioning of the body’s metabolism and immune system, but also contribute to the fight against inflammation and the decline of cognitive and bone health.

Detour to the “blue zone” of longevity

Since the gut microbiota is implicated in aging, can we learn something from the microbiota of those who live very long and healthy lives? To answer this question, Italian researchers¹ traveled to the south of Sardinia, a region famous for its centenarians. As in other “blue zones” around the world, the researchers encountered men who had above-average longevity (and women with a longer life expectancy) while remaining in good physical shape.² They hoped to discover the unique features of a gut microbiota associated with exceptional longevity, but also to evaluate the extent to which the microbiota can be inherited by descendants, and the impact of environmental factors such as diet.

Gut flora of centenarians in the prime of life 

The researchers analyzed the gut microbiota of a group of 46 dashing centenarians and nonagenarians, and compared it to a control group of 46 healthy younger adults (40-60 years old). They also compared the gut microbiota of seven centenarians with that of their children. 

They found that the gut microbiota of the centenarians had a strong presence of bacteria from the Verrucomicrobiota phylum, particularly the species Akkermansia muciniphila. Among other things, this bacterium is known to contribute to immunity, metabolic health, and maintaining the integrity of the intestinal barrier. While the gut microbiota of the youngest participants was dominated by the Bacteroidetes phylum and in particular, the genus Bacteroides, that of the nonagenarians was associated with Actinobacteria, particularly Bifidobacteria. Moreover, the gut microbiota of the centenarians was closer to that of the youngest participants than that of the nonagenarians.

According to the researchers, the gut microbiota of the centenarians was a carefully balanced microbial community. It included species associated with intestinal health that oppose the action of pathogens and have an anti-inflammatory effect that benefits the entire body. In addition, its richness and complexity allow it to adapt to environmental disturbances.

Genetics and lifestyle acting together

The study showed the gut microbiota of the centenarians to be relatively similar to that of their children. The latter may therefore inherit characteristics of the microbiota, but also family lifestyle habits, particularly dietary habits, which predispose them to longevity. Moreover, a correlation was found between the species of the gut microbiota linked to longevity and adherence to a Mediterranean diet: further evidence of the benefits of this fiber- and anti-oxidant rich diet!