Introduction:
Microbial structure is closely associated with the initiation and development of various diseases. However, the roles of urine flora in prostate diseases, including prostate cancer (PCa) and benign prostatic hyperplasia (BPH), are still unclear.

Material and methods:
In this study, clinical samples were collected from PCa (n = 21) and BPH (n = 19) patients and healthy people (n = 12). The analysis of urine flora DNA sequencing and hematological testing results between groups was performed using bioinformatic methods, including alpha and beta diversity analysis, and functional PICRUSt analysis.

Results:
The results showed that the microbial structure in PCa and BPH differed from the healthy control. Abundance of Escherichia coli was higher in PCa and BPH patients, while probiotics, such as Lactobacillus helveticus and Lactobacillus iners, were lower. Moreover, beta diversity in the PCa group was significantly different from the control group, while alpha diversity was not. Spearman analysis showed that Escherichia coli was negatively correlated with Lactobacillus helveticus and Lactobacillus iners. Functional analysis showed that microbial imbalance was associated with energy metabolism in PCa, and with cell motility, energy metabolism, and intracellular trafficking, secretion, and vesicular transport in BPH. Moreover, microbial imbalance was associated with nervous disorders and infectious diseases in PCa, and with metabolic system, infectious diseases, and signal transduction in BPH.

Conclusions:
Taken together, microbial imbalance may be associated with PCa and BPH. The increase of Escherichia coli was accompanied by the decrease of probiotics, such as Lactobacillus helveticus and Lactobacillus iners. These may be biomarkers for risk prediction and early treatment for prostate disease.