Evaluation of the relationship between urinary microbiota and bladder cancer

Recent studies suggests that the genitourinary microbiome plays a significant role in mediating the development and progression of urological tumors, including bladder cancer. In this study, we aimed to evaluate urinary microbiota analysis at the time of diagnosis in patients with bladder cancer. The study included 30 patients who were first diagnosed with bladder cancer in Eskisehir Osmangazi University Faculty of Medicine, Department of Urology and 20 age and sex matched healthy controls. Urinary microbiota analysis have been evaluated in bladder cancer and healthy control groups and patients with bladder cancer with muscle invasive bladder cancer (KIMK) or not (KIOMK). LEfSe (linear discriminant analysis effect size) analysis (LDA threshold value >2, p<0.05) was used to determine significant bacterial compositions between the groups. In the bladder cancer group and healthy control group, Firmicutes was common at phylum level, Enterococcus was the most common at genus level and Lactobacillus iners was the most common at species level. In muscle invasive bladder cancer (KIMK) cases, Veillonella dispar (70.9%) was the most common species, followed by Lactobacillus helveticus (11.3%) and Lactobacillus iners (6.0%). In the KIOMK group, L. iners (46.7%) was the most common species, followed by Staphylococcus saprophyticus (12.9%) and Eggerthella lenta (12.4%). Staphylococcus at the genus level and Staphylocccus_s at the species level were found to be dominant in the KIMK group. Streptococcus, Bifidobacterium and Ruminococcus were dominant at the genus level in the KIOMK group. In our study, it was shown that the urinary microbiota in bladder cancer cases was different from healthy controls at the time of diagnosis and the microbiota composition changed according to the presence of muscle invasion in bladder cancer cases. Further studies on the use of these changes in bladder cancer diagnosis and treatment follow-up are needed.