Review of the gut microbiome and esophageal cancer: Pathogenesis and potential clinical implications

Esophageal cancer ranks among the most aggressive malignant diseases. The limited improvements in treatment outcomes provided by conventional therapies have prompted us to seek innovative strategies for treating this cancer. More than 100 trillion microorganisms inhabit the human intestinal tract and play a crucial role in health and disease conditions, including cancer. The human intestinal microbiome is thought to influence tumor development and progression in the gastrointestinal tract by various mechanisms. For example, Fusobacterium nucleatum, which primarily inhabits the oral cavity and causes periodontal disease, might contribute to aggressive tumor behavior through activation of chemokines such as CCL20 in esophageal cancer tissue. Composition of the intestinal microbiota is influenced by diet, lifestyle, antibiotics, and pro- and prebiotics. Therefore, by better understanding how the bacterial microbiota contributes to esophageal carcinogenesis, we might develop novel cancer prevention and treatment strategies through targeting the gastrointestinal microflora. This review discusses the current knowledge, available data and information on the relationship of microbiota with esophagitis, Barrett's esophagus, esophageal adenocarcinoma and squamous cell carcinoma.