Table 1 Summary of studies on the Microbiome and Prostate cancer

Cohen R et al. 2005 [33]

34 Prostate tissues cultured from men after undergoing radical prostatectomy

Propionibacterium acnes spp was the most predominant bacteria and significant prostate tissue inflammation was observed

Sfanos KS et al., 2008 [34]

Prostatectomy tissues from 30 men with Prostate cancer underwent 16S rDNA sequencing

83 distinct microorganisms spp. identified. There was no significant association between the presence of particular species of bacteria and histologic evidence of acute or chronic inflammation.

Yow MA et al. 2017 [35]

16S rDNA sequencing on 20 snap-frozen prostate tissue cores from ten “aggressive” prostate cancer cases

Enterobacteriacae member species were found common to all samples and P. acnes in 95% of analyzed samples.

Cavarretta I et al., 2017 [36]

Performed 16S rDNA microbiome sequencing of tumor, peri-tumor, and non-tumor tissues upon radical prostatectomy.

Propionibacterium spp was the most predominant bacterial genus found in all regions of the tumor. Staphylococcus spp was the more abundant in tumor and peri-tumor areas as compared to normal tissue areas.

Feng Y et al., 2019 [37]

Metagenomics and meta-transcriptomic analysis to identify microbiota in frozen radical prostate specimens from tumor and adjacent benign tissue from 65 Chinese patients

40 unique bacterial genera were identified. Pseudomonas, Escherichia, Acinetobacter, and Propionibacterium spp were the most abundant spp. respectively.

Banerjee S et al.,2019 [38]

Microarray metagenomics analysis of formalin-fixed tissue from 50 prostate cancer patients and 15 patients with BPH

The most predominant bacteria belonged to the following phyla; Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes respectively. Among the viruses isolated, 41% were known tumorigenic viruses, including high-risk human papillomavirus (HPV 16&18), and human cytomegalovirus (HCMV)

Miyake M et al., 2019 [39]

45 prostate cancer and 33 BPH tissue specimens were screened for sexually transmitted infectious agents using PCR

Mycoplasma genitalium was the only organism independently associated with prostate cancer and with high Gleason scores

Shrestha E et al. 2018 [44]

Assessed the urinary microbiome of 135 men undergoing prostate needle biopsy

Corynebacterium, Staphylococcus, and Streptococcus species were the most predominant in both positive and negative biopsy cases. No species was significantly associated with prostate cancer.

Yu H et al. 2015 [45]

16S rRNA sequencing done on urine, seminal fluid, and expressed prostatic fluids (EPS) from men with BPH and Prostate cancer

Bacteroidetes, Alphaproteobacteria, Firmicutes bacteria, Lachnospiraceae, Propionicimonas, Sphingomonas spp. were significantly associated with Prostate cancer

Alanee S et al. 2018 [46]

Assessed the urinary and gut microbiota of 30 men undergoing trans-rectal prostate biopsy

A high abundance of Veillonella, Streptococcus, and Bacteroides spp. was found in Prostate cancer patients. No spp. was significantly associated with prostate cancer.

Liss MA et al. 2018 [57]

Assessed gut microbiota among 133 men undergoing trans-rectal prostate biopsy

There was significant differences in the microbial composition of the cancer and non-cancerous patients and non-significantly associated with Prostate cancer.

Golombos DM et al. 2018 [49]

Evaluated the gut microbiome of 20 men with BPH and prostate cancer

A high abundance of Bacteroides massiliensis in prostate cancer cases compared to BPH cases was found

Sfanos KS et al. 2018 [34]

Assessed microbiota of 30 healthy men and 30 men with localized, recurrent, and metastatic prostate cancer using 16S rDNA sequencing

There was a greater alpha diversity in the normal men compared to men with prostate cancer