Study uncovers new associations between gut microbiome and aging process

A new research paper was published in Volume 17, Issue 8 of Aging-US on August 1, 2025, titled “Causal relationships between gut microbiome and hundreds of age-related traits: evidence of a replicable effect on ApoM protein levels.”

In this study, Federica Grosso, Daniela Zanetti, and Serena Sanna from the Institute for Genetic and Biomedical Research (IRGB) of the National Research Council (CNR), Italy, uncovered new associations between gut microbiome and the aging process. The researchers found that certain microbial characteristics may causally influence proteins in the blood linked to inflammation and heart health. These findings could help explain how age-related diseases like cardiovascular conditions and macular degeneration are influenced by changes in the gut ecosystem.

The gut microbiome, the collection of microorganisms living in the digestive system, plays a major role in immune function and metabolic health. As people age, this microbial community shifts, often leading to imbalances associated with inflammation and chronic disease. To explore how these changes might affect the body, the researchers used Mendelian Randomization-a method that leverages genetic data-to test over 55,000 possible causal connections between gut microbial characteristics and age-related health indicators.

The study identified 91 significant causal relationships. Among them, the researchers found that higher levels of certain gut bacteria were associated with increased risk of age-related macular degeneration. Another finding was the association between a metabolic pathway in the gut, called “purine nucleotides degradation II,” and lower levels of apolipoprotein M (ApoM), a protein that helps protect against heart disease. This result was validated using data from an independent study, strengthening the evidence.

“Unlike previous studies, we performed replication analyses for the significant results using independent GWAS datasets, a fundamental step that has often been overlooked.”

The study also revealed how some bacteria may affect protein levels differently depending on a person’s blood type. Specifically, in individuals with blood type A, certain gut microbes that can break down a sugar called GalNAc may influence proteins related to inflammation and cardiovascular health. This suggests that personalized approaches to managing age-related diseases could consider both gut microbiota and genetic factors like blood type.

The research team followed strict guidelines to reduce false findings and confirmed its key results in independent datasets. By carefully testing for reverse causality and other biases, the authors provided strong evidence that the gut microbiome can influence critical aspects of aging biology.

Although more research is needed to fully understand the biological pathways involved, these findings suggest that targeting the gut microbiota might help delay or reduce age-related inflammation and disease. The study lays a foundation for future therapeutic strategies that could include diet, probiotics, or other microbiome-based interventions.