Prostate cancer (PC)—a major global health challenge— presents a wide spectrum of outcomes, from slow-growing tumors to aggressive metastatic disease. Despite advances in screening and treatment, age-related risk, persistent inflammation, and lifestyle factors continue to drive disease burden worldwide. Diet, obesity, and physical inactivity can further shape disease outcomes by altering the gut and genitourinary microbiomes. Emerging research shows these microbial communities actively shape inflammation, hormone metabolism, and also treatment responses.
This new IPA blog explores how microbial dysbiosis contributes to prostate cancer risk and how targeted microbiome strategies, such as probiotics, may offer new opportunities to support prostate health and improve therapeutic outcomes.
Prostate cancer, in brief
As the second most commonly diagnosed cancer among men worldwide, PC brought nearly 1.5 million new cases and 396,000 deaths in 2022.
PC is often detected through prostate-specific antigen (PSA) testing and digital rectal exams, and many cases grow slowly enough that men live for years without symptoms. When caught early, the 5-year survival rate is nearly 100%. Men with metastatic (stage IV) prostate cancer that has spread to distant organs have a far worse outlook, with an average five-year survival of only about 28%.
The cancer arises from the interplay of genetic risk and environmental factors. Key contributors include aging, family history, and inherited genetic variants, alongside external factors such as diet, lifestyle, chronic diseases, and exposure to infections that drive persistent inflammation. Together, these biologic, environmental, and inflammatory processes create conditions that promote malignant transformation in prostate tissue.
While a man’s age and genetic background are non-negotiable, environmental contributors are modifiable. In this group are eating habits and obesity, which are associated with the progression of PC. Several lifestyle factors are suggested to contribute to the dysbiosis of the body’s microflora, potentially increasing the risk of developing cancers.
Treatment
For some men with early-detected PC, a “watchful waiting” or active surveillance approach may be recommended instead of immediate treatment, while others undergo surgery, radiation, or hormone therapy. Even when treatments are used, tumor heterogeneity can affect response, and disease relapse remains a possibility over time.
In recent years, attention has focused on the microbiome and its potential role in prostate cancer development and response to treatment.
Microbiome involvement in prostate cancer
Mounting evidence from studies of both the gut and genitourinary microbiomes indicates that microbial imbalances can shape PC development, progression, and treatment responses through intertwined inflammatory, metabolic, and immune pathways.
Genitourinary microbiome and prostate cancer
Growing evidence suggests that dysbiosis in the prostate and genitourinary microbiome may contribute to PC by driving chronic inflammation and reshaping local immune responses. While no single pathogen explains PC development, microbial shifts have been linked to benign prostatic hyperplasia, inflammation, and cancer-related outcomes. Preclinical models show that uropathogenic E. coli can trigger prostatitis, epithelial proliferation, and DNA damage. In addition, Propionibacterium acnes—the most frequently detected species in prostate tissue—has been associated with increased PC risk and pro-inflammatory activity. Sequencing studies further reveal reduced microbial diversity, with additional work identifying Helicobacter pylori and oncogenic viruses in PC samples. Together, these findings point to a role for microbial inflammation and disruption in PC development, though a distinct “prostate microbiome” has yet to be clearly defined.
Gastrointestinal microbiome and prostate cancer
Research increasingly indicates that the gut microbiome plays a significant role in PC development and progression by shaping inflammation, metabolism, and host immune responses. Dysbiosis can exacerbate inflammation, compromise the intestinal barrier, and produce metabolites in ways that contribute to DNA damage and tumorigenesis. A rectal-swab microbiome study of men undergoing prostate biopsy found that, although overall bacterial diversity was similar between groups, men diagnosed with PC showed modest but significant enrichments of Bacteroides and Streptococcus species.
Similarly, another study found that men with PC, compared to benign controls, exhibited elevated Bacteroides massiliensis and reduced Faecalibacterium prausnitzii, a key butyrate (SCFA) producer with anti-inflammatory and anti-tumor properties.
Together, these studies underscore a complex interplay in which gut microbial composition and function may influence both PC risk and biological behavior.
Diet and prostate cancer
Diets high in saturated fat of animal origin, such as red meat and dairy—as well as obesity driven by these patterns—are linked to higher prostate cancer risk by promoting inflammation, hormonal changes, and metabolic stress. Growing evidence suggests the gut microbiome may amplify these effects, as high-fat or Western diets can disrupt microbial balance and produce metabolites that circulate systemically and influence tumor-related pathways in the prostate. These interactions highlight how lifestyle factors and the microbiome may act in concert to shape PC development and progression.
Gut microbiota modulation and prostate cancer
Given these connections, emerging therapies are exploring how modifying the gut microbiome may help influence PC outcomes. Importantly, these approaches are not presented as stand-alone cancer treatments, but as ways to help maintain a healthy microbiome that supports prostate health and may complement standard medical care.
Antibiotics
In mouse models, antibiotics alter the gut microbiome, dampen insulin-like growth factor-1 signaling, and inhibit high-fat-diet–driven PC growth. Yet their broad disruption of microbial balance can also favor harmful, inflammation-associated bacteria, making the overall effects mixed.
One recent population-based retrospective study (over one million individuals) found a higher risk of PC with long-term use of antibiotics, but clinical data remain inconclusive.
Probiotics
Probiotics can help rebalance the gut microbiome and counter harmful microbial activities, a mechanism that may be relevant to PC because gut–systemic signaling influences inflammation, metabolism, and immune responses linked to tumor progression.
Early preclinical research shows that selected probiotics may suppress prostate tumor growth and promote apoptosis.
Although human data are limited, one randomized trial in 208 men on active surveillance showed that adding a five-strain Lactobacillus probiotic blend to a phytochemical supplement significantly slowed PSA progression and reduced inflammation.
Gut microbiome and response to treatment
Microbial effects on therapy can shape how treatments work and how well patients tolerate them, as disruptions to the gut ecosystem can drive inflammation, alter immune signaling, and worsen toxicity.
Radiotherapy, chemotherapy, and immunotherapy all reshape the gut microbiota, sometimes enhancing antitumor immunity or drug activation but also driving dysbiosis, inflammation, and treatment-related toxicity.
Androgen deprivation therapy (ADT) produces similarly complex effects: it can reduce beneficial taxa like lactobacilli and expand inflammatory or androgen-producing bacteria that promote endocrine resistance, yet in other settings—particularly when PC itself depletes microbes such as Akkermansia muciniphila—ADT appears to partially reverse these shifts and restore A. muciniphila, a microbe shown in preclinical models to slow tumor progression and enhance ADT efficacy.
Together, these insights highlight the potential for targeted microbial interventions to improve response and lessen toxicity to various prostate cancer therapies.
Takeaway
Prostate cancer progression is shaped by genetics, age, and lifestyle factors that disrupt the gut and genitourinary microbiomes. These microbial imbalances drive inflammation, alter metabolism, and affect immune responses. They also influence how patients respond to treatments. Emerging targeted microbial interventions—including probiotics and diet-based strategies—show promise for slowing tumor growth, reducing inflammation, and improving therapy outcomes. Together, these findings highlight the microbiome as a potential multifaceted target in PC management.
Key references
“Prostate Cancer Prognosis.” Johns Hopkins Medicine, Johns Hopkins University, Accessed 21 Nov. 2025.
“Prostate-Specific Antigen (PSA) Test.” MedlinePlus, U.S. National Library of Medicine,. Accessed 21 Nov. 2025.
Banerjee, Sagarika et al. “Microbiome signatures in prostate cancer.” Carcinogenesis vol. 40,6 (2019): 749-764. doi:10.1093/carcin/bgz008
Boehm, Bayli J et al. “Acute bacterial inflammation of the mouse prostate.” The Prostate vol. 72,3 (2012): 307-17. doi:10.1002/pros.21433
Cui, Junfeng et al. “Gut microbiota and urological cancers: from microecological imbalance to potential for precision therapy.” Discover oncology vol. 16,1 1799. 2 Oct. 2025, doi:10.1007/s12672-025-03296-3
Davidsson, Sabina et al. “Frequency and typing of Propionibacterium acnes in prostate tissue obtained from men with and without prostate cancer.” Infectious agents and cancer vol. 11 26. 9 Jun. 2016, doi:10.1186/s13027-016-0074-9
Fujita, Kazutoshi et al. “Gut microbiome and prostate cancer.” International journal of urology : official journal of the Japanese Urological Association vol. 29,8 (2022): 793-798. doi:10.1111/iju.14894
Fujita, Kazutoshi et al. “Obesity, Inflammation, and Prostate Cancer.” Journal of clinical medicine vol. 8,2 201. 6 Feb. 2019, doi:10.3390/jcm8020201
Fujita, Kazutoshi et al. “The Gut-Prostate Axis: A New Perspective of Prostate Cancer Biology through the Gut Microbiome.” Cancers vol. 15,5 1375. 21 Feb. 2023, doi:10.3390/cancers15051375
Golombos, David M et al. “The Role of Gut Microbiome in the Pathogenesis of Prostate Cancer: A Prospective, Pilot Study.” Urology vol. 111 (2018): 122-128. doi:10.1016/j.urology.2017.08.039
Jain, Sumeet et al. “Escherichia coli, a common constituent of benign prostate hyperplasia-associated microbiota induces inflammation and DNA damage in prostate epithelial cells.” The Prostate vol. 80,15 (2020): 1341-1352. doi:10.1002/pros.24063
Katongole, Paul et al. “The human microbiome and its link in prostate cancer risk and pathogenesis.” Infectious agents and cancer vol. 15 53. 31 Aug. 2020, doi:10.1186/s13027-020-00319-2
Kustrimovic, Natasa et al. “Microbiome and Prostate Cancer: A Novel Target for Prevention and Treatment.” International journal of molecular sciences vol. 24,2 1511. 12 Jan. 2023, doi:10.3390/ijms24021511
Kwon, Whi-An et al. “Prostate Cancer at the Microbial Crossroads: Illuminating a New Frontier in Precision Medicine.” The world journal of men’s health, 10.5534/wjmh.250045. 31 Jul. 2025, doi:10.5534/wjmh.250045
Liss, Michael A et al. “Metabolic Biosynthesis Pathways Identified from Fecal Microbiome Associated with Prostate Cancer.” European urology vol. 74,5 (2018): 575-582. doi:10.1016/j.eururo.2018.06.033
Matsushita, Makoto et al. “Gut Microbiota-Derived Short-Chain Fatty Acids Promote Prostate Cancer Growth via IGF1 Signaling.” Cancer research vol. 81,15 (2021): 4014-4026. doi:10.1158/0008-5472.CAN-20-4090
Matsushita, Makoto et al. “Influence of Diet and Nutrition on Prostate Cancer.” International journal of molecular sciences vol. 21,4 1447. 20 Feb. 2020, doi:10.3390/ijms21041447
Miyake, Makito et al. “Prostate diseases and microbiome in the prostate, gut, and urine.” Prostate international vol. 10,2 (2022): 96-107. doi:10.1016/j.prnil.2022.03.004
Park, Sun Jae et al. “Association between antibiotic use and subsequent risk of prostate cancer: A retrospective cohort study in South Korea.” International journal of urology : official journal of the Japanese Urological Association vol. 31,4 (2024): 325-331. doi:10.1111/iju.15364
Pernigoni, Nicolò et al. “Commensal bacteria promote endocrine resistance in prostate cancer through androgen biosynthesis.” Science (New York, N.Y.) vol. 374,6564 (2021): 216-224. doi:10.1126/science.abf8403
Platz, Elizabeth A et al. “A Prospective Study of Chronic Inflammation in Benign Prostate Tissue and Risk of Prostate Cancer: Linked PCPT and SELECT Cohorts.” Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology vol. 26,10 (2017): 1549-1557. doi:10.1158/1055-9965.EPI-17-0503
Rosa, Lana S et al. “Antiproliferative and apoptotic effects of probiotic whey dairy beverages in human prostate cell lines.” Food research international (Ottawa, Ont.) vol. 137 (2020): 109450. doi:10.1016/j.foodres.2020.109450
Salachan, Paul Vinu et al. “Microbiota of the prostate tumor environment investigated by whole-transcriptome profiling.” Genome medicine vol. 14,1 9. 25 Jan. 2022, doi:10.1186/s13073-022-01011-3
Schafer, Elizabeth J et al. “Recent Patterns and Trends in Global Prostate Cancer Incidence and Mortality: An Update.” European urology vol. 87,3 (2025): 302-313. doi:10.1016/j.eururo.2024.11.013
Sekhoacha, Mamello et al. “Prostate Cancer Review: Genetics, Diagnosis, Treatment Options, and Alternative Approaches.” Molecules (Basel, Switzerland) vol. 27,17 5730. 5 Sep. 2022, doi:10.3390/molecules27175730
Sfanos, Karen S et al. “Compositional differences in gastrointestinal microbiota in prostate cancer patients treated with androgen axis-targeted therapies.” Prostate cancer and prostatic diseases vol. 21,4 (2018): 539-548. doi:10.1038/s41391-018-0061-x
Terrisse, Safae et al. “Immune system and intestinal microbiota determine efficacy of androgen deprivation therapy against prostate cancer.” Journal for immunotherapy of cancer vol. 10,3 (2022): e004191. doi:10.1136/jitc-2021-004191
Thomas, Robert J et al. “Increasing Phytochemical-rich Foods and Lactobacillus Probiotics in Men with Low-risk Prostate Cancer-A Randomised, Double-blind, Placebo-controlled Trial.” European urology oncology, S2588-9311(25)00257-3. 27 Oct. 2025, doi:10.1016/j.euo.2025.10.003
Wheeler, Karen M, and Michael A Liss. “The Microbiome and Prostate Cancer Risk.” Current urology reports vol. 20,10 66. 7 Sep. 2019, doi:10.1007/s11934-019-0922-4
Yadav, Anjali et al. “From microbes to medicine: harnessing the gut microbiota to combat prostate cancer.” Microbial cell (Graz, Austria) vol. 11 187-197. 23 May. 2024, doi:10.15698/mic2024.05.824
Zhang, Jintao et al. “Sodium Butyrate Induces Endoplasmic Reticulum Stress and Autophagy in Colorectal Cells: Implications for Apoptosis.” PloS one vol. 11,1 e0147218. 19 Jan. 2016, doi:10.1371/journal.pone.0147218
