Exploring the bladder tissue microbiome in patients with muscle-invasive bladder cancer using 2bRAD-M sequencing

Objectives The 2bRAD sequencing for Microbiome (2bRAD-M) represents an innovative and streamlined approach for the reconstruction of microbial profiles at the species level. In our investigation, we conducted 2bRAD-M analysis to characterize the microbiome of bladder tissue in patients with muscle-invasive bladder cancer (MIBC). Methods 15 tumor tissues and 15 paired para-carcinoma tissues were obtained from the bladder excised during surgery. 2bRAD-M sequencing was used to assess the abundance of microorganisms in samples. Results The microbial community structure and biodiversity, as assessed at varying taxonomic ranks, exhibited a high degree of similarity between the tumor and paired non-tumor tissues. At the genus level, we observed a notably elevated abundance of Brachybacterium and Haloparvum, coupled with a diminished abundance of Anoxybacillus, Anoxybacillu_A, Deinococcus, NCEH01, and Pseudoxanthomonas_A in the tumor tissues. Meanwhile, at the species level, the non-tumor tissues exhibited an enrichment of Anoxybacillus_A rupiensis, Anoxybacillus flavithermus_G, Klebsiella quasipneumoniae, NCEH01 sp002304505, and Pseudoxanthomonas_A sp004284195. Linear discriminant analysis effect size (LEfSe) identified 29 discriminative features, characterized by significant variations (p<0.5, LDA >= 2.0) in relative abundance between the two groups. Furthermore, an analysis of functional predictions utilizing Phylogenetic Investigation of Communities by Reconstruction of Unobserved States 2 (PICRUSt2) also uncovered disparities in the microbial functional composition. Conclusions This study identified several microorganisms that exhibit differences between MIBC tumor tissue and adjacent non-tumor tissue using 2bRAD-M sequencing, providing some insights into the potential association between the bladder microbiome and cancer.