The Role of the Microbiome and Green Tea Catechins in Prostate Cancer: Contemporary Issues in Research

Clinical research targeting men with localized prostate cancers is a challenging endeavor. The guidelines and standards for management - active surveillance versus definitive therapy although well established in recent years, patients continue to grapple with the decision to stay on active surveillance. Accumulating evidence supports green tea catechins (GTCs) in chemoprevention for prostate cancer (PCa), a leading cause of cancer morbidity and mortality among men. GTCs include (-)-epigallocatechin-3-gallate, which has been shown to modulate molecular pathways involved in prostate carcinogenesis. Previous research on GTCs suggested that they are bioavailable, safe, and effective at modulating clinical and biological markers associated with prostate cancer. GTCs may be especially beneficial to those with low-grade PCas, which are typically managed with careful monitoring through active surveillance (AS). The gut microbiome enzymatically transforms GTC structure when administered orally, altering its bioavailability, bioactivity, and toxicity. In addition to xenobiotic metabolism, the gut microbiome has multiple other physiological effects potentially involved in PCa progression, including regulating inflammation, hormones, and other known/unknown pathways. Therefore, the contemporary approach in future clinical trials is to consider not only the independent role of chemopreventive agents such as GTCs, but in addition, include the synergestic role of the gut microbiome in the context of PCa chemoprevention, as they may relate to individual responses to GTCs, which, in turn, can enhance clinical decision-making.