BACKGROUND: The gut microbiome has emerged as a potential influencer of muscle health
however, its role in hospitalized patients remains unclear. This study aimed to investigate the association between gut microbiome diversity and skeletal muscle mass, strength, and quality in hospitalized post-stroke patients. METHODS: We conducted a cross-sectional study of post-stroke patients admitted to a rehabilitation facility. Gut microbiome diversity was assessed using 16S ribosomal ribonucleic acid (rRNA) gene sequencing, calculating Operational Taxonomic Unit (OTU) Richness, Faith's Phylogenetic Diversity (PD), and Shannon index. Muscle health was evaluated using skeletal muscle index (SMI) for muscle mass, handgrip strength (HGS) for muscle strength, and bioimpedance analysis-derived phase angle (PhA) for muscle quality. Multiple linear regression analyses were performed, adjusting for potential confounders. RESULTS: A total of 156 patients (mean age 78.4 years
55.7 % male) were analyzed. OTU Richness showed significant positive associations with SMI (β = 0.197, p = 0.025), HGS (β = 0.180, p = 0.005), and PhA (β = 0.178, p = 0.022). The Shannon index was also positively associated with SMI (β = 0.120, p = 0.041), HGS (β = 0.140, p = 0.028), and PhA (β = 0.164, p = 0.032). Faith's PD did not demonstrate significant associations with muscle health parameters. CONCLUSIONS: Higher gut microbiome diversity, assessed by OTU Richness and Shannon index, is associated with better muscle mass, strength, and quality in post-stroke patients. These findings suggest a potential role for gut microbiota in muscle health during stroke rehabilitation.