Gut microbiota alpha diversity in hemodialysis patients versus controls: A meta-analysis of chao1, shannon index, and observed species

BACKGROUND Changes in gut microbiota have attracted attention in the pathogenesis of chronic kidney disease (CKD), as microbial imbalance may contribute to systemic inflammation and the accumulation of toxic metabolites that influence advancement of the illness. OBJECTIVES This study aimed to assess differences in gut microbiota alpha diversity between hemodialysis patients and controls by employing a systematic review and meta-analysis methodology. METHODS A systematic review and meta-analysis was conducted with a literature search in PubMed, Embase, and Scopus databases up to February 25, 2026. Study selection was done following the PRISMA protocol. Data extracted included study characteristics and gut microbiota alpha diversity indices. For the systematic review and meta-analysis, the inverse variance method with standardized mean difference (SMD) and 95% confidence interval (CI) was used, with heterogeneity and publication bias examined. RESULTS Nine studies were included. The Chao1 index showed no notable difference between groups (SMD: −0.14; 95% CI: −0.78–0.55; p: 0.7390). In contrast, the Shannon index was considerably greater in hemodialysis patients than controls (SMD: 0.49; 95% CI: 0.03–0.96; p: 0.0380). The observed species index also showed no significant difference (SMD: 0.99; 95% CI: −0.56–2.54; p: 0.2090). CONCLUSION Hemodialysis patients had a significantly higher Shannon index than controls, indicating alterations in gut microbial community structure in patients undergoing hemodialysis. However, the findings should be interpreted with caution due to high heterogeneity.