What the gut microbiome of the world’s oldest person can tell us about ageing

When María Branyas Morera died in 2024 at the age of 117, she left more than memories. She left science a gift: samples of her microbiome.

Researchers discovered her gut was as diverse as someone decades younger: rich in beneficial bacteria linked to resilience and longevity. Her daily yoghurt habit and Mediterranean diet may have helped. While we can’t all inherit “lucky genes”, nurturing our microbiome may be one way to support lifelong health.

In a recent paper in Cell Reports Medicine, researchers presented what may be the most detailed scientific investigation of a supercentenarian (a person aged 110 or older). Before her death, Branyas agreed to participate in research aimed at uncovering how she lived such a long and healthy life.

Read more: Centenarian blood tests give hints of the secrets to longevity

When scientists compared her samples with those of people who had not reached such exceptional ages, the genetic results were unsurprising: Branyas carried protective variants that guard against common diseases. But they also looked at something over which we have more control – the gut microbiome.

This microbiome is the vast community of bacteria, fungi and other microorganisms that live in the intestines. They help digest food, produce vitamins, influence our immune system and even communicate with the brain. While our genes play only a small role in shaping our microbiome, diet and lifestyle are far more important.

Normally, as people age, gut microbiomes lose diversity – the variety of microbial species – and beneficial microbes such as Bifidobacterium decline. This reduction in diversity has been linked to frailty.

Branyas’s gut told a different story. Her microbiome was as diverse as that of a much younger adult and was especially rich in the bacterial family Bifidobacteriaceae, including the genus Bifidobacterium. In most older people these bacteria decline, but Branyas’s levels matched previous reports of elevated Bifidobacterium in other centenarians and supercentenarians. The researchers concluded that this unusually youthful microbiome may have supported her gut and immune health, contributing to her extraordinary longevity.

Bifidobacteria are among the first microbes to colonise an infant’s gut and are generally considered beneficial throughout life. Studies link them to supporting immune function, protecting against gastrointestinal disorders and helping regulate cholesterol.

Her diet offered a clue to why she maintained such high levels of Bifidobacterium. Branyas reported eating three yoghurts every day, each containing live bacteria that are known to support the growth of Bifidobacterium. She also followed a largely Mediterranean diet, a pattern of eating consistently linked to gut microbiome diversity and good health.

Other foods that encourage Bifidobacterium include kefir, kombucha and fermented vegetables such as kimchi and sauerkraut. These contain probiotics – live bacteria that can settle in the gut and confer health benefits. But probiotics need fuel. Prebiotics – dietary fibres we can’t digest but that our microbes thrive on – are found in foods like onions, garlic, leeks, asparagus, bananas, oats and legumes. Together, probiotics and prebiotics help maintain a balanced microbiome.

Of course, this was a study of a single individual, and the scientists are not claiming that her microbiome alone explains her long life. Her extraordinary longevity was almost certainly the result of many interwoven factors: protective genes, efficient metabolism, low inflammation – and, quite possibly, the support of a diverse gut microbiome.

Microbiome research is advancing rapidly, but no one yet knows what the “perfect” microbiome looks like. Greater diversity is generally associated with better health, but there is no single recipe for a long life. Even so, Branyas’s case reinforces a growing consensus: nurturing a diverse, beneficial microbiome is linked to better health and resilience.

While we cannot choose our genes, we can support our gut microbes. Simple steps include eating fermented foods, such as live yoghurts, kefir, kimchi and sauerkraut, as well as fruit, vegetables, legumes and whole grains, which supply the prebiotics that healthy microbes need.

Following a Mediterranean-style diet – built around vegetables, fruits and whole grains, with olive oil as the main fat, fish and legumes eaten regularly, and red meat, processed foods and added sugars kept to a minimum – has been repeatedly linked to both microbiome diversity and reduced disease risk.

These habits will not guarantee a lifespan beyond 110, but they are associated with lower risks of cancer, type 2 diabetes and cardiovascular disease.

María Branyas Morera’s life is a reminder that longevity depends on a delicate balance of genetics, lifestyle and biology. We cannot control every factor, but tending to our gut microbiome is one meaningful step toward lasting health.

Rachel Woods does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.