Short-Term Longitudinal Analysis of Gut Microbiota Dynamics During Anti-CD19 CAR-T Cell Therapy in Diffuse Large B-Cell Lymphoma Patients

Purpose: Alterations in gut microbiota may influence immune response and treatment outcomes in patients with diffuse large B-cell lymphoma (DLBCL). However, the dynamics during anti-CD19 CAR-T cell therapy remain unclear. Methods: We conducted a short-term longitudinal microbiome analysis in DLBCL patients (n=12) undergoing CAR-T cell therapy targeting CD19. Stool samples were collected at baseline, 1 week, and 2 weeks post-infusion. 16S rRNA gene sequencing was used to assess microbial diversity, taxonomic composition, and functional pathways. Correlation analyses were then conducted between microbial taxa and inflammatory biomarkers. Results: , were positively associated with lymphocyte counts and inversely correlated with C-reactive protein levels. Conclusion: Gut microbiota alterations following CAR-T infusion, characterized by increased Bacteroidota abundance, specific taxonomic shifts, and enhanced lipoic acid metabolism, may provide early microbial signatures for monitoring immune modulation in DLBCL patients.