Compositional Characteristics of the Gut Microbiome in Patients with Acute Uremia: A Study in India

Background: Acute uremia may disrupt intestinal barrier function and microbial composition through the gut-kidney axis, but evidence from Indian populations is limited. This study compared gut microbial composition, diversity, predicted function, and uremic-toxin associations in patients with acute uremia and healthy controls. Methods: In this cross-sectional case-control study, 60 adults with acute uremia secondary to KDIGO stage 3 acute kidney injury and 60 age-, sex-, and BMI-matched healthy controls were enrolled. Stool samples obtained within 24-48 hours of admission underwent V3-V4 16S rRNA gene sequencing. QIIME 2 and SILVA-based analyses assessed alpha and beta diversity, differential taxonomic abundance, and predicted metabolic pathways. Serum urea, creatinine, indoxyl sulfate, and p-cresyl sulfate were measured. Results: Acute uremia was associated with lower richness and alpha diversity (Chao1 and Shannon indices, both p < 0.001) and distinct beta-diversity clustering (PERMANOVA p = 0.001). Proteobacteria increased, whereas Firmicutes and the Firmicutes-to-Bacteroidetes ratio decreased. Escherichia-Shigella, Klebsiella, Enterococcus, Streptococcus, and Clostridium perfringens were enriched; Faecalibacterium, Roseburia, Blautia, Bifidobacterium, and Coprococcus were depleted. Indoxyl sulfate and p-cresyl sulfate correlated positively with Enterobacteriaceae and negatively with short-chain-fatty-acid-producing taxa. Predicted urease and indole-biosynthesis pathways were increased. Conclusion: Acute uremia in this Indian cohort was associated with gut dysbiosis characterized by loss of microbial diversity and short-chain-fatty-acid producers, expansion of potential pathobionts, and associations with circulating uremic toxins. These findings support further evaluation of microbiota-targeted interventions in acute kidney injury.