# Diet-informed metagenomic clocks for aging in the Integrative Longevity Omics Study

**Authors:** Tanya Karagiannis, Anastasia Leshchyk, Meghan Short, Ye Chen, Sarah Bald, Stacy Andersen, Daniel Segrè, Paola Sebastiani

PMC · DOI: 10.1093/geroni/igaf122.4101 · 2025-12-31

## TL;DR

This study creates aging clocks using gut microbiome data and shows that diet influences how the microbiome ages, offering new insights into healthy aging.

## Contribution

The paper introduces microbiome-based aging clocks that incorporate diet metrics like caloric intake and a novel Nutrient Variety Index.

## Key findings

- Microbiome-based aging clocks were developed using shotgun metagenomics data from 267 individuals.
- Adjusting for caloric intake and Nutrient Variety Index improved clock accuracy, showing diet's role in microbiome aging.
- The approach highlights microbial signatures linked to healthy aging and diet-influenced pathways.

## Abstract

Aging is a heterogeneous process that unfolds uniquely across individuals and biological systems. Aging clocks, computational models trained on molecular data to estimate biological age, offer a promising framework for investigating aging biology at the individual level. While most clocks rely on epigenetic, transcriptomic, or proteomic data, the human microbiome remains an underutilized source of aging biomarkers despite its central role in host metabolism, immune regulation, and inflammation, all of which are influenced by diet and linked to aging. To explore microbiome-mediated aging, we developed aging clocks using shotgun metagenomics sequencing data from 267 individuals in the Integrative Longevity Omics cohort, including centenarians and their offspring. These clocks estimate biological age based on taxonomic composition across multiple taxonomic levels. To account for dietary influences, we incorporated total caloric intake and a novel metric developed by our group, the Nutrient Variety Index (NVI), which summarizes the distribution of nutrient groups within a diet. Adjusting for caloric intake and NVIs significantly improved clock performance, suggesting that nutrient composition modulates microbiome aging. This integrative approach enhances biological age estimation and has the potential to uncover microbial signatures of healthy aging. Our findings underscore the importance of diet in shaping aging trajectories and highlight the potential of microbiome-based clocks to uncover nutrition-linked aging pathways.

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Source: https://tomesphere.com/paper/PMC12762698