Exploring the Link Between Obligate Anaerobe-Related Dysbiosis and Prostate Cancer Development: A Pilot Study

Several independent studies have associated prostate cancer (PCa) with specific groups of bacteria, most of them reporting the presence of anaerobic or microaerophilic species such as Cutibacterium acnes (C. acnes). Such findings suggest a prostate cancer-related bacterial dysbiosis, in a manner similar to the association between Helicobacter pylori infection and gastric cancer. In an earlier exploratory study looking for such dysbiosis events, using a culturomics approach, we discovered that the presence of obligate anaerobes (OAs) along with C. acnes was associated with increased prostate-specific antigen (PSA) levels in 39 participants.

Building on this, in this study, we analyzed 89 post-rectal examination urine samples, from men with prostate cancer attending the PROVENT trial, using 16S rDNA sequencing. Our investigation focused on the impact of six previously identified OA genera (Finegoldia, Fusobacterium, Prevotella, Peptoniphilus_A, Peptostreptococcus, and Veillonella_A) on PSA levels. However, an additional data-driven approach was followed to uncover more taxa linked to increased PSA.

Our analysis revealed a statistically significant association between Peptostreptococcus and elevated PSA levels. Additionally, there were potential interactions between Prevotella and Fusobacterium. Interestingly, we also found that an aerobe, Ochrobactrum_A,was significantly linked to higher PSA levels.

These findings suggest that OA-related dysbiosis may contribute to elevated PSA levels through prostate cell damage even before prostate cancer develops, possibly playing a role in chronic inflammation and the hypervascular changes seen in precancerous lesions. Future clinical trials with larger cohorts are needed to further evaluate the role of OA in prostate cancer development and progression.