Aim: This study aimed to investigate the association between energy intake and gut microbiome diversity in patients following stroke.
Methods: A cross-sectional study was conducted with 156 patients following stroke aged ≥65 years admitted to a rehabilitation hospital (mean age, 78 ± 7 years; 69 women). Energy intake was calculated from average food consumption during the first week after admission. Gut microbiome diversity was assessed using three indices derived from 16S rRNA sequencing of stool samples: the Shannon index, operational taxonomic unit (OTU) richness and Faith's phylogenetic diversity (PD). Sex-stratified multiple linear regression analysis evaluated the association between energy intake and gut microbiome diversity, adjusting for confounders such as age, body weight, inflammation markers, nutritional status, and medication.
Results: The study included 156 patients following stroke (mean age, 78 ± 7 years; 69 women). The median energy intake was 1600 (interquartile range [IQR], 1400-1800] kcal/day for all participants. The median for gut microbiome diversity indices were Shannon index, 6.3 (IQR, 5.9-6.5); OTU richness, 217.3 (IQR, 181.9-258.1); and Faith's PD, 22.4 (IQR, 19.3-27.2). In women, energy intake was significantly positively associated with the Shannon index (β = 0.233, P = 0.026), OTU richness (β = 0.228, P = 0.036), and Faith's PD (β = 0.212, P = 0.038). In men, energy intake was significantly positively associated with the Shannon index (β = 0.230, P = 0.027), OTU richness (β = 0.211, P = 0.040), and Faith's PD (β = 0.198, P = 0.043).
Conclusions: Adequate energy intake may play an important role in preserving gut microbiome diversity in patients. Further longitudinal studies are needed to confirm these associations, clarify causality, and explore underlying mechanisms. Geriatr Gerontol Int 2025; 25: 535-542.
Keywords: energy intake; gut microbiome diversity; nutritional assessment; post‐stroke; protein intake.
© 2025 Japan Geriatrics Society.