Convergent Gut Microbiome Remodeling Across Ischemic Stroke, Myocardial Infarction, and Longevity Reveals a Shared Ecological Signature of Aging and Disease

Gut microbiota dysbiosis has been associated with ischemic stroke (IS), myocardial infarction (MI), and aging, but whether these contexts share reproducible microbial features remains unclear. We conducted an exploratory and hypothesis-generating descriptive study of genus-level microbiota patterns across an internal IS cohort and publicly available external IS, MI, and age-stratified or longevity-associated datasets. Analyses were performed within predefined age strata and interpreted cautiously because of the small internal cohort, cross-cohort heterogeneity, and the absence of direct metabolite, intestinal barrier, inflammatory, or microbial activity measurements. No taxon in the internal cohort remained statistically significant after false-discovery-rate correction; therefore, all taxonomic observations were treated as descriptive. Candidate overlapping features included repeated detection of Escherichia-Shigella and Klebsiella and non-uniform patterns among genera previously associated with short-chain fatty acid metabolism, including Faecalibacterium, Blautia, and Roseburia. Lachnoclostridium and Bacteroides showed opposite abundance gradients in selected cross-dataset comparisons. These observations suggest possible ecological overlap across ischemic disease and age-associated microbiome contexts, but they do not establish causality, disease-specific biomarkers, or shared microbial function. The mechanistic models discussed in this manuscript are literature-informed hypotheses based on exploratory compositional data and require future validation in larger, harmonized longitudinal cohorts using metagenomic, metabolomic, clinical, and experimental measurements.