BARCELONA, Dec 1, 2025 — Want to protect your brain as you age? A growing body of research suggests the answer might be on your plate—specifically, a Mediterranean diet. A six-year study of 746 older adults has pinpointed a “microbial fingerprint” linked to this eating pattern and a slower rate of cognitive decline, offering fresh clues about how what we eat impacts brain health.
Mediterranean Diet & Brain Health: It’s About Your Gut
Research reveals a link between the Mediterranean diet, gut bacteria, and preserved cognitive function in aging adults.
- Following a Mediterranean diet is associated with a healthier gut microbiome.
- A specific “microbial fingerprint” has been identified in people who closely adhere to the diet.
- This fingerprint is linked to slower cognitive decline in older adults at risk for metabolic issues.
- The gut-brain axis plays a crucial role in these benefits.
The study, published in BMC Medicine, followed 746 older adults with high cardio-metabolic risk for six years. Researchers evaluated their adherence to the Mediterranean diet, analyzed the composition of their gut microbiota, and tracked changes in cognitive function over time. The results were clear: those who more closely followed the diet exhibited a more favorable gut microbiome and experienced a more positive cognitive evolution.
What’s the gut got to do with it? The connection lies in the gut-brain axis, a two-way communication system where microorganisms in the gut produce compounds that can influence brain function. Cognitive function encompasses essential abilities like memory, attention, learning, language, and decision-making—all vital for maintaining independence.
One of the most innovative aspects of the research was the identification of a specific “microbial fingerprint” characteristic of the Mediterranean diet. This biomarker, based on the presence and abundance of certain gut bacteria, was also associated with slower cognitive decline. “This study demonstrates that the intestinal microbiota is a key element in the cognitive benefits of the Mediterranean diet,” explains Jiaqi Ni, the study’s first author and a predoctoral researcher at the Universitat Rovira i Virgili (URV). “Our results suggest that some intestinal bacteria associated with greater adherence to this dietary pattern could protect against cognitive decline.”
Jordi Salas-Salvadó, a professor at URV and director of the study, emphasizes that identifying this microbial fingerprint “opens new opportunities to design nutritional or microbial interventions aimed at promoting healthy cognitive aging.” Researchers Nancy Babio and Stephanie K. Nishi, from the Department of Biochemistry and Biotechnology at URV, highlight the importance of these findings given the growing aging population and the increasing prevalence of dementia, noting that improving diet quality is a simple, accessible strategy for supporting brain health.
The research was a collaborative effort involving researchers from the PREDIMED-Plus consortium and led by Jiaqi Ni, under the direction of Jordi Salas-Salvadó, Nancy Babio, and Stephanie K. Nishi, all members of the Human Nutrition Unit at the Department of Biochemistry and Biotechnology of the URV. This study is part of a larger, ongoing investigation into the relationship between diet, gut microbiota, and brain health throughout the aging process.
Bibliographic reference: Ni J, Hernández-Cacho A, Nishi SK, Babio N, Belzer C, Konstati P, Vioque J, Corella D, Castañer O, Vidal J, Moreno-Indias I, Torres-Collado L, Coltell O, Fitó M, Ruiz-Canela M, Wang DD, Tinahones FJ, Salas-Salvadó J. Mediterranean diet, gut microbiota, and cognitive decline in older adults with obesity/overweight and metabolism syndrome: a prospective cohort study. BMC Med. 2025 Dec 1;23(1):669. doi:10.1186/s12916-025-04488-y.
