- Scientists have found a type of gut bacteria that may help feed tumors
- Normally ‘gut worms’ are good for us but cancer and other diseases can ruin it
- Discovery could lead to new cancer treatments like yogurt and poo transplants
Scientists have found that normal gut bacteria can promote tumor growth in prostate cancer patients and allow them to survive the effects of treatment.
Prostate cancer is usually treated with hormone therapy, which works by suppressing male hormones called androgens.
But British scientists have found that having low androgen levels can lead to an overgrowth of gut bacteria, which can then ‘take over’ hormone production.
The study, conducted by the Institute of Cancer Research in London, identified ‘bacterial fingerprints’ that could help identify patients who will become resistant to treatment.
The researchers suggest that these men may benefit from strategies to manipulate their gut microbiome.
For example, men can undergo a stool transplant or what researchers hope to produce a yogurt drink enriched with friendly bacteria.
Prostate cancer kills 11,800 men every year in the UK, which is equivalent to the death of one man every 45 minutes and 26,000 men every year in the US.
Gut bacteria are generally beneficial to human health but a new study has found that they can sometimes help feed tumors in prostate cancer.
Study author and Professor of Experimental Cancer Medicine Johann de Bono said: ‘Our findings suggest that initiation of hormone therapy for prostate cancer may trigger ‘gut worms’ to start producing androgen hormones.
‘These androgens can then perpetuate prostate cancer growth and increase resistance to hormone therapy – worsening survival outcomes for men.’
Professor de Bono said that while more research is needed, the discovery could lead to new treatments that manipulate gut bacteria to act in patients’ favor.
This can take the form of a yogurt drink with live bacteria that do not produce cancer-promoting hormones, or a stool transplant from someone else with different gut bacteria.
A stool transplant is the transfer of stool from a donor into a patient’s gastrointestinal tract.
This is usually the recurrent C. difficile infection – spread by bacterial spores found within feces where it is 90 percent effective.
Gut bacteria are part of our microbiome, a collection of microorganisms that normally live in the body, and are generally valuable to humans by aiding in digestion.
However, cancer and other diseases can upset this balance – for example, by promoting the expansion of gut bacteria and encouraging cancer cells to release toxins or other molecules that affect them.
The study found that getting rid of all gut bacteria in mice with prostate cancer slowed tumor growth and delayed the emergence of hormone resistance.
This further revealed that transplanting the faeces of mice with hormone-resistant prostate cancer into mice with low androgen levels promoted tumor growth.
ICR Chief Executive Professor Christian Helin said the results of the study represent a new way of looking at cancer.
“The impact of the gut microbiome on cancer is a fascinating new area of science that we are just beginning to understand,” he said.
What is prostate cancer?
How many people does it kill?
More than 11,800 men in the UK every year – or one every 45 minutes – die from the disease, compared to around 11,400 women who die from breast cancer.
This means that prostate cancer is behind only the lungs and bowel in terms of how many people kill in the UK.
In the US, the disease kills 26,000 men every year.
Despite this, it receives less than half the funding for breast cancer research and treatments for the disease are at least a decade behind.
How quickly does it develop?
Prostate cancer usually develops slowly, so one may have no signs for many years, according to NHS.
If the cancer is in an early stage and is not causing symptoms, a policy of ‘watchful waiting’ or ‘active surveillance’ may be adopted.
Some patients can be cured if the disease is treated at an early stage.
But if it is diagnosed at a later stage, when it has spread, it becomes terminal and treatment revolves around relieving symptoms.
Known side effects from treatment, including erectile dysfunction, keep thousands of men from seeking a diagnosis.
testing and treatment
Trials for prostate cancer are randomized, with precise tools only beginning to emerge.
There is no national prostate screening program because over the years the tests have been horribly wrong.
Doctors struggle to differentiate between aggressive and less serious tumors, which makes it difficult to decide on treatment.
Men over the age of 50 are eligible for a ‘PSA’ blood test, which gives doctors an idea of whether a patient is at risk.
But it is unbelievable. Patients with a positive result are usually given a biopsy, which is not foolproof.
Scientists are uncertain about the cause of prostate cancer, but age, obesity and lack of exercise are known risks.
Anyone with any concerns can speak to the specialist nurses for Prostate Cancer UK on 0800 074 8383 or visit prostatecancer.org