Researchers have identified five types of bacteria that are linked to aggressive prostate cancer.
The bacteria was common in urine and tissue samples from men with the disease, according to a new study.
It is hoped that the results could help pave the way for treatments that could target this bacteria and slow or prevent the development of an aggressive disease.
Scientists don’t yet know how people get the bacteria or if they cause the disease.
Professor Colin Cooper, project leader of the project, from Norwich Medical School at the University of East Anglia (UEA), said: “We already know some strong associations between infections and cancer.
“For example, the presence of the bacterium Helicobacter pylori in the digestive tract can lead to stomach ulcers and is associated with stomach cancer, and certain types of HPV viruses can cause cervical cancer.
“We wanted to find out if bacteria could be linked to how prostate cancer grows and spreads.”
Dr Jeremy Clark, also from UEA’s Norwich Medical School, said: “Although prostate cancer is responsible for a large proportion of all cancer deaths in men, it is more often of a disease from which men rather die than of.
“And little is known about the causes of some prostate cancers becoming more aggressive than others.
“We now have evidence that certain bacteria are involved in this and are part of the puzzle.”
The team worked with researchers from Norfolk and Norwich University Hospital, the Quadram Institute and other collaborators to analyze urine or tissue samples from more than 600 patients with and without prostate cancer.
They have developed methods to find the bacteria associated with aggressive prostate cancer.
Dr Rachel Hurst, first author of this work and also from UEA’s Norwich Medical School, said: “We have found several types of bacteria associated with aggressive prostate cancer, some of which are new types of bacteria never before found before.”
Two of the new species of bacteria discovered by the team are named after two of the study’s funders – Porphyromonas bobii, according to The Bob Champion Cancer Trust, and Varibaculum prostatecancerukia, according to Prostate Cancer UK.
The set of bacteria found by the team includes Anaerococcus, Peptoniphilus, Porphyromonas, Fenollaria and Fusobacterium.
All bacteria like to grow without the presence of oxygen.
Dr Hurst said: ‘When any of these specific anaerobic bacteria were detected in patient samples, it was linked to the presence of higher grades of prostate cancer and more rapid progression to aggressive disease.
“We have also identified potential biological mechanisms of how these bacteria may be linked to cancer.
“Among the things we don’t know yet are how people catch these bacteria, whether they cause cancer, or whether a poor immune response allows the bacteria to grow.
“But we hope our findings and future work can lead to new treatment options that could slow or prevent the development of aggressive prostate cancer.
“Our work could also lay the groundwork for new tests using bacteria to predict the most effective treatment for each man’s cancer.”
The researchers also noted that many bacteria are beneficial to human life, and it is not straightforward to eliminate harmful bacteria without removing the protection provided by good bacteria.
The study, published in European Urology Oncology, was funded by The Bob Champion Cancer Trust and Prostate Cancer UK.