This landmark UK study – led by academics from the University of Bedfordshire alongside a team from Addenbrooke’s and Bedford, Cambridge University Hospital Trusts alongside globally renowned scientists from the University of Southern California and Australia – evaluated a dietary intervention which boosted plant-based nutrients combined with a specifically designed probiotic supplement.

The study involved 212 men with prostate cancer who were being monitored and not receiving androgen deprivation therapy but had increasing prostate-specific antigen (PSA) levels at baseline. All participants took a specially developed supplement made from natural, plant-based ingredients including broccoli, turmeric, pomegranate, green tea, ginger and cranberry. Half of the group also received a new probiotic supplement, while the other half received a placebo.

The scientific results, published in the acclaimed medical Journal European Urology Oncology, reported at 44% reduction in PSA progression, a key indicator of prostate cancer activity. The study is notable in that these biochemical changes were backed up with physical changes in disease size seen on MRI scan – a level of reassurance never seen before in a nutritional study.

The other ‘world first’ findings, welcomed by the men in the study, were improvements in urinary flow. Men on the combination got up less at night to pass water and even had better erectile function. By improving their gut health, the men felt significantly better, had lower levels of inflammation in their bodies and were even stronger (measured by formal grip strength).

Although links between gut health, diet and cancer have been established in previous laboratory studies, this is the first robust clinic trial in humans showing these can be targeted and have an effect on cancer progression and symptoms.

Professor Robert Thomas – Visiting Professor of Sport and Nutritional Science at the University of Bedfordshire, Consultant Clinical Oncologist at Addenbrooke's and Bedfordshire Cambridge University Hospitals, and Head of Integrative Oncology at University College Hospital London – worked on the research and said: “This study shows, for the first time, that improving the balance of bacteria in the gut can slow prostate cancer activity while also improving important aspects of men’s health such as urinary symptoms, inflammation and physical strength. What is particularly reassuring is that the changes we saw in PSA were supported by changes on MRI scans, which is very unusual and unique in nutritional research. This was a carefully designed clinical trial carried out under medical supervision and, while the results are encouraging, longer follow up is planned to assess whether these supplements will lead to less men needing major interventions such as surgery or radiotherapy.”

As well as providing much needed practical evidence-based nutritional advice for men with prostate cancer – which is the most common cancer in men – it provides encouragement for research institutes across the world to embark on more microbiome research related to different cancers and their treatments.

Dr Jeffrey Aldous, Senior Lecturer in Exercise Physiology, also contributed to the study. He added: “This research helps us understand how targeted dietary strategies may influence the gut microbiome in ways that appear to benefit both cancer-related markers and overall wellbeing. Improvements in strength, inflammation and daily symptoms are particularly important for quality of life, and I hope our findings can support and improve the lives of those living with prostate cancer.”