Researchers may have uncovered a crucial clue that contributed to the remarkable longevity of Maria Branyas Morera, who passed away at the age of 117. One of the distinctive factors about Branyas was her unique gut microbiome.

A team of scientists from the University of Barcelona, led a study on Branyas’ longevity, with the findings reported earlier this month by the Spanish media outlet Ara. The researchers discovered that Branyas had a microbiome that closely resembled that of an infant. This unique combination of microbial passengers, combined with her fortunate genetics and healthy lifestyle choices, may have enabled Branyas to live a long and relatively healthy life, according to the scientists.

Branyas was born in the United States in 1907, but soon after, her family relocated to Catalonia, Spain. She worked as a nurse throughout her life, often alongside her physician husband Joan Moret until his death in 1976. In 2000, she moved to a retirement home in Northern Catalonia, with many years still ahead of her.

In January 2023, Branyas was officially recognized by Guinness World Records as the oldest living woman globally, following the death of 118-year-old Lucile Randon of France. Around that time, University of Barcelona geneticist Manel Esteller and his team convinced her to undergo a series of medical tests in hopes of unraveling some of the secrets behind her longevity. The team has since discovered several factors that likely contributed to Branyas’ long life.

For instance, Branyas possessed exceptional genetics that slowed down the age-related progression of her body’s cells. The researchers estimated that her cellular age may have been 17 years younger than her actual age. Branyas also made healthy lifestyle choices, avoiding vices like alcohol and smoking, regularly walking, adopting a Mediterranean diet, and maintaining a rich social life (she and Moret had three children and two dozen grandchildren and great-grandchildren). Additionally, she had a unique gut microbiome, the community of usually harmless and often helpful bacteria that live in our guts. According to Esteller’s team, Branyas’ microbiome had a similar composition to those found in infants.

Notably, Branyas didn’t just live for a long time; she also experienced very few major medical issues and maintained a sharp memory and lucid mind until the very end, Esteller said. Branyas lived through both World Wars, the Spanish Civil War, and two major pandemics: the 1918 Spanish flu and covid-19, the latter of which only caused her a mild bout of the viral disease. However, last August, Branyas finally passed away at the age of 117—peacefully in her sleep, according to her family.

The microbiome is believed to play a crucial role in many aspects of our health, and an unbalanced microbiome can contribute to various health issues. While scientists are still trying to understand exactly how the microbiome influences our health, it’s clear that Branyas had many other vital factors contributing to her longevity. The researchers hope that their study on her and other long-lived individuals can lead to discoveries that could benefit everyone.