A plant-rich diet paired with targeted probiotics may help slow the progression of prostate cancer while improving men’s overall health, according to a major new UK study.
Researchers found, for the first time, that actively improving gut bacteria can influence prostate cancer activity in men who are being monitored rather than treated with surgery, radiotherapy or hormone therapy. The findings also suggest tangible quality-of-life benefits, including better urinary function, reduced inflammation and improved physical strength.
Landmark clinical trial
The study, led by academics from the University of Bedfordshire alongside clinicians from Addenbrooke’s and Bedfordshire Cambridge University Hospitals, brought together international expertise from the University of Southern California and Australia.
It followed 212 men with prostate cancer whose disease was being closely monitored. None were receiving androgen deprivation therapy, but all had rising prostate-specific antigen (PSA) levels at the start of the trial.
All participants were given a supplement made from plant-based ingredients including broccoli, turmeric, pomegranate, green tea, ginger and cranberry. Half of the group also received a newly developed probiotic, while the remainder were given a placebo.
Measurable changes in cancer activity
Results published in the medical journal European Urology Oncology showed a 44% reduction in PSA progression among men taking the combined plant supplement and probiotic.
Crucially, researchers say the biochemical changes were backed up by physical evidence. MRI scans revealed changes in disease size, offering a level of confirmation rarely seen in nutritional studies.
Improvements beyond cancer markers
The benefits were not limited to cancer indicators. Men taking the combined intervention reported better urinary flow, fewer night-time trips to the bathroom and improvements in erectile function.
Researchers also recorded lower levels of inflammation and increased physical strength, measured through grip tests, suggesting broader health gains linked to improved gut health.
First robust human evidence
While laboratory studies have long suggested links between diet, gut bacteria and cancer, this is the first large-scale human clinical trial to demonstrate that these factors can be deliberately targeted to affect cancer progression and symptoms.
Professor Robert Thomas, who worked on the study, said the findings marked a significant step forward.
“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.”
A wider impact on quality of life
The study also highlights the potential of targeted nutrition to improve daily life for men living with prostate cancer, which remains the most common cancer among men.
Dr Jeffrey Aldous, who also contributed to the research, said the findings could have far-reaching implications.
“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.”
Researchers say the work provides practical, evidence-based insight for patients and clinicians, while encouraging further global research into the role of the microbiome in cancer treatment and prevention.
