Abstract 10150: Distinct Gut Microbiota Composition Among Older Adults with Impaired Left Ventricular Diastolic Function

Abstract

Introduction: Recent research has demonstrated shifts in intestinal microbial composition in response to cardiovascular disease (CVD) development. Left ventricular (LV) diastolic dysfunction is an early manifestation of myocardial ageing. We aimed to examine whether gut microbial composition is associated with LV diastolic function among healthy older adults. Methods: Among community older adults, 15 subjects with preserved LV ejection fraction on echocardiography underwent gut microbial composition examination in this proof-of-concept cross-sectional study. Myocardial relaxation (diastolic function) was impaired in those subjects with lower ratios of peak early (E) to late diastolic (A, atrial contraction) velocities. Metagenomic reads from stool samples were analyzed after excluding human reference genome data, and classified into various microbial taxonomic groups using lowest-common-ancestor algorithm. Statistical analysis was performed using linear discriminant analysis (LDA). Results: The subjects (53% males, mean age 75±4 years) were stratified into Groups 1 (n=8) and 2 (n=7) with more severe and lesser diastolic dysfunction, respectively, based on E/A ratios (0.77 vs. 1.28, p<0.0001). In Group 1, there was significantly higher prevalence of certain bacteria (p<0.05), including Bacteroides sp, Ruminococcus sp., and Paraprevotella (Figure 1). The largest relative effect size was with Bacteroides sp., including Bacteroides xylanisolvens (logarithmic LDA score 3.0). In Group 2, there was significantly higher prevalence (p<0.05) of Oscillibacter sp., Peptostreptococcaceae, Clostridioides difficile, Prevotella timonensis, and Blautia producta. Relative effect size was largest with Oscillibacter sp. (log 2.8). Conclusions: Distinct gut microbiota were associated with more severe vs. lesser LV diastolic dysfunction. Future validation in larger cohorts is warranted for targeting the microbiome in myocardial ageing.