Microbiota-immunity-hormones axis: what the impact on cancer development and progression

The human microbiota, made up of trillions of microorganisms residing in our body, plays a critical role in preserving host health and immune homeostasis but its dysbiosis has a relevant impact on development and progression of various diseases, including cancer. The most studied links between the microbiota and cancer are: 1. Inflammation and Immune System Modulation: GM plays a key role in modulating inflammation and immunity. Persistent inflammation is a known risk factor for various cancer types. When dysbiosis occurs, it can contribute to chronic inflammation which, in turn, can promote cancer development. 2. The modulation of circulating hormones: since GM can metabolize estrogen and androgens compounds, it can potentially affect the balance of circulating hormones in the body with implications for hormones-related cancers. 3. Anti-cancer therapies: GM can modulate and influence the effectiveness of ant-cancer treatments, such as chemo-radio therapies or immune checkpoint inhibitors. 4. Short chain fatty acids (SCFAs): Some GM bacteria are able to produce the SCFA that have been shown to have anti-inflammatory and anti-cancer properties by regulating cell proliferation and differentiation and inhibiting cancer cells growth. By comprehensively exploring the interaction between the microbiota, immunity and the endocrine system, this special issue aims to elucidate the mechanisms by which microbiota dysbiosis may contribute to the cancer onset, progression and treatments; and to provide valuable insights into future directions of research and clinical interventions in this exciting field.