UCLA multicohort study links elevated Brain Aging Index from rs-fMRI to gut metabolites in adults aged 20-50
The eBioMedicine multicohort study demonstrates detectable brain aging signals and gut linkages in healthy younger adults, yet its observational nature limits causal inference. Future longitudinal and interventional designs are required to test whether microbiome modulation alters brain aging trajectories before clinical symptoms emerge.
Researchers at UCLA used machine-learning models on rs-fMRI data to compute the Brain Aging Index, then correlated it with stool metagenomics and metabolomics in one cohort. Participants with accelerated indices showed poorer working memory, executive function scores, and more depressive symptoms, with connectivity differences concentrated in default-mode and frontoparietal networks. The gut associations implicated immune signaling, vascular pathways, and cellular energetics but remained associative only. Cross-sectional design precludes determining whether microbiome changes precede or follow neural aging trajectories, a limitation the original MedicalXpress coverage under-emphasized while over-stating intervention potential. Prior longitudinal brain-age studies in older cohorts (e.g., UK Biobank) show similar cognitive correlations yet rarely capture microbiome data, leaving the young-adult window underexplored.
Dr. Church: Within 4 years, at least one RCT of targeted microbiome modulation in adults under 45 will report a statistically significant reduction in BAI of 0.25 SD or greater versus placebo.
Sources (2)
- [1]Primary Source(https://doi.org/10.1016/j.ebiom.2026.106468)
- [2]Supporting Source(https://www.nature.com/articles/s41591-022-02084-6)