Gut microbiota as a predictive tool for outcomes in IgA nephropathy

Immunoglobulin A nephropathy (IgAN) is characterized by the deposition of glycosylation-deficient IgA1 in the glomeruli and has been linked to the gut-kidney axis. This study aimed to determine if baseline differences in gut microbiota could predict therapeutic responses in IgAN patients. We analyzed fecal microbiomes of 55 biopsy-confirmed IgAN patients and followed them for over 6 months. Patients were classified as responders (n = 39) or nonresponders (n = 16) based on remission status. Fecal microbiomes were profiled using 16S rRNA sequencing, revealing significant microbiota differences. Nonresponders had increased Proteobacteria and Firmicutes, with notable enrichment of opportunistic bacteria like Escherichia-Shigella and Pseudomonas. A predictive classifier based on 24 amplicon sequence variants, with Escherichia-Shigella and Pseudomonas as key contributors, showed high accuracy in identifying nonresponders (AUC 0.9103, p