Gut Bacteria May Fuel Prostate Cancer Growth Prostate cancer foundation

[podsart]

How does advanced prostate cancer continue to grow, despite hormone therapy? A new study implicates bacteria in the gut that make testosterone, fueling the tumor. This groundbreaking insight may also offer a new approach to treatment.

While the vast majority of prostate cancer is treatable, in 2021, nearly 34,000 patients are estimated to die of the disease – most of an advanced form known as castration-resistant prostate cancer (CRPC). These tumors continue to grow and spread, even as their “fuel supply”—testosterone—is lowered by androgen deprivation therapy (ADT). To date, the reasons behind progression to CRPC are not completely known, but a closer look into our gut microbiota, or “bugs in the gut,” may provide some answers.

According to a recent PCF-funded study by Pernigoni and colleagues published in the prestigious journal Science, when you start on ADT, bacteria in your gut can start making testosterone. This can provide prostate cancer cells with an alternative “fuel supply,” resulting in a cancer that can continue to grow.

Normally, trillions of bacteria and other micro-organisms live on and in our bodies, largely benefiting us through functions such as helping to digest our food and regulate our immune system. But certain bacteria may have dangerous consequences for some patients with prostate cancer.

Through an elegant series of studies in mice and in patients with prostate cancer, the researchers demonstrated the complex relationships among gut bacteria, hormone levels, patient outcomes, and even antibiotic therapy. They found that patients with prostate cancer on ADT had higher amounts of certain types of bacteria (Akkermansia and Ruminococcus) that have the ability to make androgens. When these “bad” gut bacteria—the ones making testosterone—were transplanted from patients with CRPC into mice with hormone-sensitive prostate cancer, the researchers saw tumors grow and become resistant to treatment. On the other hand, some bacterial species appear to be beneficial. In patients, having more Prevotella bacteria in the gut was linked to improved survival.

The researchers also tested the effect of antibiotics in mouse models of prostate cancer. Treating these mice with antibiotics killed off gut bacteria…..and slowed tumor progression. Similarly, giving mice more Prevotella bacteria also slowed tumor growth.

Looking ahead, bacterial “fingerprints” may identify men with gut microbiota who may benefit from intervention. Although much more work needs to be done in humans to ensure efficacy and safety, this may eventually lead to use of fecal transplant of “good bacteria” or antibiotic therapy. Patients with prostate cancer may someday be able to take a sort of “yogurt drink” enriched with “good” bacteria to counter the production of androgens.

Other questions remain unanswered. For example: how do gut bacteria sense low testosterone, triggering them to synthesize the hormone? Uncovering the mysteries behind CRPC is critical to the fight against this disease. If these findings on androgen-producing gut bacteria bear out in the clinic, doctors and patients may have new—and perhaps unexpected—defenses.

[dhccpa]

Sounds like more work needs to be done.

[noahware]

This is the kind of thing that makes me wonder if the wide range of disease response to some interventions (whether medical, or related to diet or supplements) is not sometimes highly dependent on how a given individual's gut biome reacts to that intervention.

It also make me wonder if this is one of the reasons abiraterone prolongs life better than ADT: the certain types of bacteria that have the ability to make androgens are partly limited in their ability to do so by abi, as it inhibits needed CYP enzymes in the gut just as it does elsewhere.

[Graham49 in reply to noahware]

Along a similar line. I wonder when drugs are initially tested on mice, whether any attention is given to try and achieve a gut biome similar to that in humans? Are the mice fed human type food or typical food you might feed to a pet mouse?

[podsart]

Recent news about the communication between gut bacteria and the brain and other body systems have begun to unveil the important role the gut biome plays. At this point, I am taking a simple route of eating some sauerkraut daily for a source of good bacteria in fermented foods. Also, yogurt for the same reason.

[j-o-h-n]

Mother's milk.....

Good Luck, Good Health and Good Humor.

j-o-h-n Saturday 12/11/2021 11:33 PM EST

[podsart in reply to j-o-h-n]

Thanks