Human Gut Microbiome Influences Prostate Cancer Growth: Study Says

With the advancements in understanding the human gut microbiome, a recent study highlights how the gut bacteria influences hormone metabolism and subsequently amplifies the tumor growth of prostate cancer and even suggests how it disrupts specific hormone treatments.

Recently, a number of relationships between the living bacteria in the human gut and cancer have been discovered. It has been shown that the microbiome can increase a person's risk of developing bowel cancer by influencing the adverse chemotherapy side effects.

Understanding Prostate Cancer

(Photo: Lukas Rychvalsky from Pexels)

Prostate cancer, according to the Mayo Clinic, is cancer growth in a man's prostate. The prostate is a small walnut-like gland that produces seminal fluid, nourishes and transports sperm.

Prostate cancer is now one of the most common forms of cancer. Many see a slow growth of cancer in their prostate and are confined to the gland, where they may not cause serious adverse effects. However, some types of prostate cancer are slow and require only minimal to no treatment, far more aggressive forms spread rapidly.

During its early stages, prostate cancer often causes no clinical symptoms. However, as it progresses and becomes more aggressive, some symptoms include trouble urinating, blood in the urine, bone pain, decreased force in the stream of urine, weight loss, erectile dysfunction, and blood in semen.

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Relationship Between Microbiome and Prostate Cancer

The recent research published in the journal Science, titled "Commensal bacteria promote endocrine resistance in prostate cancer through androgen biosynthesis," focuses on a common prostate cancer treatment known as androgen deprivation therapy. Androgens are hormones that are necessary for cancerous cells to grow. Hence, depriving the patient of androgen slows down the growth or, for some even shrinks, the prostate tumor.

Using various mouse experiments, the recent study was first able to demonstrate how human gut bacteria produce androgen hormones that encourage the growth of prostate cancer tumors. Animal studies reveal that certain types of gut bacteria respond to ADT by producing similar metabolites that inevitably render the hormonal treatment ineffective.

Researchers then analyzed two groups of human prostate cancer patients, those with hormone-resistant prostate cancer, versus men with prostate cancer that have been responsive to ADT. When fecal samples were drawn from patients with hormone-resistant prostate cancer, these were transplanted into mice with prostate cancer. Researchers found that those tumors developed hormone treatment resistance and subsequently grew faster than their counterparts.

Comparing microbiome profiles between the two groups revealed that patients with hormone-resistant prostate cancer had heightened levels of the Ruminococcus bacteria. On the other hand, patients responding well to ADT had high levels of the Prevotella stercorea bacteria. Researchers say that the study results have great implications on the potential development of gut bacteria signatures that could show attending doctors the optimal therapy for different prostate cancer patients.

Hypothetically, a vast number of therapies can be developed to improve the outcome of androgen deprivation therapy in light of the recent findings.