The human gut microbiome and noncoding RNAs (ncRNAs) represent interconnected regulatory networks that profoundly influence cancer development, particularly in gastrointestinal and endocrine-related malignancies. This chapter delineates the intricate interplay of microbiome-ncRNA crosstalk in the context of gastrointestinal and endocrine-related cancers. The chapter begins with a comprehensive overview of the taxonomic and functional landscape of the healthy adult gut microbiome. The gut microbiome, comprising trillions of microorganisms, plays a crucial role in endocrine regulation through hormone metabolism, synthesis of bioactive compounds, and modulation of immune responses, thereby establishing a critical crosstalk with the host endocrine system. Dysbiosis, or microbial imbalance, has been linked to endocrine dysfunction and the pathogenesis of various diseases, including gastrointestinal and endocrine-related cancers. We then elucidate the classifications of noncoding RNAs and their function as key molecular regulators in cellular communication, gene expression, and disease progression. NcRNAs contribute significantly to the development and progression of endocrine-related malignancies. The intricate crosstalk between the gut microbiome and host ncRNAs demonstrates how gut dysbiosis can disrupt host ncRNA expression patterns, thereby affecting oncogenic pathways, immune surveillance, and metabolic reprogramming linked to tumor initiation, progression, and metastasis. Conversely, host-derived ncRNAs, secreted into the gut lumen, can directly shape microbial gene expression. In this section, we explore how dysregulation of this axis contributes to carcinogenesis through the promotion of chronic inflammation, epithelial barrier dysfunction, and oncogenic signaling. Therapeutic strategies targeting this interplay, including probiotics, prebiotics, fecal microbiota transplantation, and dietary interventions, are introduced in the context of restoring microbial balance. This comprehensive chapter provides crucial insights into the molecular mechanisms governing microbiome-ncRNA interactions and their implications for cancer biology, offering new perspectives for therapeutic interventions in gastrointestinal and endocrine-related malignancies.