Introduction
The microbiome's impact on human health and illness is becoming increasingly evident. The microbiome has a major impact on the pathophysiology and risk of cancer. The human microbiota is essential to numerous biological functions in both health and illness. A collection of bacteria, viruses, fungi, and archaea that live in a host is known as the microbiota. In contrast, the microbiome is the genomes and genes of the microbiota and the environment they inhabit. There is a symbiotic equilibrium between the gut microbiota and the host.
Stressors, including illness, aging, food, smoking, and numerous other environmental variables, can disturb this homeostasis state, leading to microbial dysbiosis. To comprehend the microbiome's function in numerous disease processes, including the etiology of cancer, it is essential to comprehend the mechanisms underlying this particular niche and balance.
Modulating the immune system through mediators of chronic inflammation is the main mechanism by which the microbiota can change cancer risk and progression. Reactive oxygen and nitrogen species, which can damage DNA and cause cancer, are examples of carcinogenic metabolites that these can turn on. The second most frequent malignancy in men worldwide is prostate cancer.
What Is Microbiome?
The human microbiome is regarded as the second genome. Compared to humans, it has 150 times more gene coding. The microbiome varies with age, but after adulthood, it stabilizes comparatively. Hence, one may consider a person's distinct microbiome their "fingerprint." With the development of metagenomics, it has become easier to identify and understand the roles of most anaerobic microbes in the intestinal microbiota.
According to recent research, the microbiome interacts with the human host to influence various aspects of health, development, homeostasis, gene expression, and disease occurrence. The microbiota's two main functions are protecting the host from harmful microbes and controlling metabolic processes. Most significantly, the microbiome contributes to homeostasis maintenance and the maturation of the innate and adaptive immune systems. Globally, prostate cancer is the second most frequent cancer among men.
Dysbiosis is the term used to describe the imbalance between the harmful and protective dynamics of microorganisms. It has been documented that inflammatory bowel disease, obesity, diabetes, colorectal cancer, cardiovascular disease, and neurological disorders are linked to intestinal microbial dysbiosis. In most cases, environmental and host genetic variables interact to cause cancer. Microbes may be a significant component in cancer biology in addition to hereditary components.
What Is Prostate Cancer?
In Korea, prostate cancer ranks fourth among all cancers inflicted on males, but in the United States, it is the most prevalent variety. Its incidence in Korea is rising extremely fast, much like its high frequency in the United States. Determining the process by which prostate cancer progresses is so crucial. Diet and lifestyle factors are known to play a role in the onset of prostate cancer. Obesity and a diet high in animal fat are specifically identified as risk factors for prostate cancer. Prostate cancer development is linked to persistent inflammation. A major factor in these illnesses is the gut microbiome. The host's inflammatory and immunological responses are impacted by the gut microbiota, which is also highly controlled by dietary habits.
How Short Chain Fatty Acid Affect Prostate Cancer?
The breakdown of indigestible food substrates by intestinal microbes produces short-chain fatty acid, a form of waste. The three main short-chain fatty acids are butyrate, propionate, and acetate. Two main categories of bacteria make short-chain fatty acids. Bacteroidetes create propionate and acetate, while Firmicutes make butyrate.
Since short-chain fatty acids are generated during the digestion of dietary fiber, modifications to the host's diet can significantly alter the composition of the gut microbiota and impact microbial metabolite production. It has been shown that a high-fiber diet can enhance microbial short-chain fatty acid production, and a continuous low-fiber diet can limit short-chain fatty acid production, resulting in abrupt shifts in serum short-chain fatty acid levels.
As previously stated, patients with prostate cancer may have distinct microbiomes based on their race. Nonetheless, high-grade prostate cancer is linked to an increase in the metabolism of starch and sucrose in addition to changes in the microbiome. The gut microbiota's short-chain fatty acids play a role in the control of HDACs (histone deacetylases). Given that it impacts immune cell migration, chemotaxis, cell adhesion, cytokine production, and programmed cell death, this may be crucial for maintaining cell homeostasis. Therefore, changing the microbiota to manipulate short-chain fatty acid levels in the digestive tract may be a viable cancer treatment and prevention approach.
How Microbiota Affect Prostate Cancer Treatment?
Evidence suggests that the gut microbiota influences how the body reacts to many medications, including chemotherapy. It has been shown that cyclophosphamide shortens the gut's villi, facilitating microorganism translocation and entry into secondary lymphoid organs such as the tonsils, spleen, and lymph nodes. According to their hypothesis, cyclophosphamide enhances the gut microbiota's anti-tumor immune responses through lymphoid organ invasion. Additionally, the investigation revealed that cyclophosphamide-induced accumulation of type 17 T helper (TH17) and type 1 T helper (TH1) cell responses required a particular subset of gram-positive bacteria, including Lactobacillus johnsonii, Lactobacillus murinus, and Enterococcus hirae. An association between compositional variations in the gut microbiota and the use of oral androgen deprivation treatments (ADT), such as Bicalutamide, Enzalutamide, and Abiraterone acetate, was proposed by a study. According to the study, individuals who have been diagnosed with prostate cancer have significantly different gut microbiota alpha diversity than men who have not.
Conclusion
The microbiome can influence tumor growth and progression, either favorably or unfavorably. By boosting anti-tumor immunity, certain bacteria may prevent or cure cancer. On the other hand, microbiota may generate substances that lead to tumor growth by causing inflammatory or immunosuppressive reactions. The microbiome can affect both systemic and local immune responses by using several metabolites, including short-chain fatty acids. While the exact impact of short-chain fatty acids on prostate cancer is yet unknown, new research indicates that it negatively affects the disease's ability to progress.
