Centenarians: a young microbiota, the secret of longevity?

The intestinal microbiota, that is to say the microorganisms that make up the flora, and intake of fermented foods, are associated with health and longevity. Certain gut bacteria influence health not only in the gut but also in other parts of the body because they play a role in immunity and even communicate with the brain. Our diet and our lifestyle are the key factors that shape the composition of the microbiota.

Overall, it is accepted that the diversity of the intestinal microbiota declines with age: for example, beneficial bacteria such as bifidobacteria lose ground. But we still have a lot to learn about the link between longevity and the microbiota.

Gut microbiota and healthy aging

A study published in the journal mSphere suggests that healthy aging requires good gut health (1). The researchers reached this conclusion by studying the intestinal bacteria of more than 1,000 people aged from 3 years old to more than 100 years old. All participants were in very good health and had no family history of diseases. The results showed a direct link between health and the bacteria present in the intestine. The overall composition of the gut microbiota of healthy older people was similar to that of people decades younger. Eventually, there were few differences between the intestinal microbiota of centenarians and that of younger people. The diversity of the intestinal microbiota remained high in the study population, regardless of age.

These results are confirmed by a recent study on the microbiota of a supercentenarian: María Branyas Morera, who died in 2024 at the age of 117, who donated samples of her microbiota to science. This is what Dr Rachel Wood (University of Lincoln) says in a recent article (2). “Before her death, Branyas agreed to take part in a study to find out how she was able to live so long and in good health.she explains. When scientists compared her samples to those of people who had not reached such an exceptional age, the genetic results were not surprising: Branyas carried variants that were protective against common diseases.

The study of its intestinal microbiota yielded other information (3). Particularly rich in bifidobacteriaespecially of the type Bifidobacterium, it was as diverse as that of a much younger adult. The microbiota of Madame Branyas, apparently “young”, could therefore have contributed to the good health of her intestine, her immune system and her longevity.

Ms. Branyas followed a Mediterranean diet

But why did this supercentenarian have so many bifidobacteria? It was probably due to his diet. “Ms. Branyas said she eats three yogurts a day, each containing live bacteria known to promote the growth of bifidobacteria, explains Rachel Wood. She also followed a largely Mediterranean diet, an eating pattern consistently associated with gut microbiome diversity and good health.”

How to take care of your microbiota

Researchers suggest that by “resetting” the microbiota of an elderly person to tend towards that of a thirty-year-old, we could improve or preserve their health. Certain dietary and lifestyle habits have a negative impact on our microbiota: pesticides, ultra-processed foods which contain additives and preservatives, the abuse of antibiotics, excess sugar… However, an imbalance in our intestinal microbiota harms our immune system.

To take care of your intestinal microbiota, you can adopt a few dietary rules:

• favor the organic fruits and vegetables ;
• consume whole foods, legumes, fermented foods (kefir, kombucha, lacto-fermented vegetables, etc.) which provide natural probiotics;
• avoid refined sugars ;
• also think about the contributions in prebiotic fiberwhich nourish the good bacteria of the microbiota. They are found in onions, garlic, leeks, legumes, whole grains, etc.

“The life of María Branyas Morera reminds us that longevity depends on a delicate balance between genetics, lifestyle and biologyconcludes Rachel Wood. We can’t control every factor, but taking care of our gut microbiome is an important step toward lasting health.”

To go further: The magic of fermented foods