Gut Microbiome: Associations with Liver and Colon Cancer

The human body is home to approximately 100 trillion microorganisms, collectively referred to as the human microbiota, with their genomes forming the human microbiome. Key sites of colonization include the skin, oral cavity, respiratory tract, gastrointestinal tract, and urogenital system, with each site exhibiting a distinct microbial composition due to niche-specific adaptations. The most abundant and diverse microbial community resides in the gastrointestinal tract, particularly the colon. The gut microbiome has emerged as a critical player in human health, influencing metabolic, immunological, and neurological pathways. It is involved in nutrient metabolism, energy harvesting, and the production of short-chain fatty acids (SCFAs) and essential vitamins. The gut microbiome also plays a pivotal role in immune system development, maintaining intestinal homeostasis, and influencing neurodevelopment through the gut–brain axis. Dysbiosis, or alterations in the microbiome composition, is linked to various diseases such as inflammatory bowel disease, liver diseases, metabolic disorders, and cancers. Given its central role in human health, the gut microbiome presents promising therapeutic opportunities, including probiotics, prebiotics, synbiotics, postbiotics, and fecal microbiota transplantation, for disease prevention and treatment.