Emerging Insights into the Esophageal Microbiome

PURPOSE OF REVIEW: Analysis of the esophageal microbiome remains a relatively new field of research, and most studies to date have focused on characterizing the esophageal microbiome in states of health and disease. Microbiome alterations have been implicated in the pathogenesis of inflammatory and neoplastic conditions in the colon and elsewhere in the gastrointestinal tract. The epidemiology of various esophageal conditions including Barrett’s esophagus (BE), esophageal adenocarcinoma (EAC), esophageal squamous cell carcinoma (ESCC) and eosinophilic esophagitis (EoE) point to the microbiome as a potential co-factor in disease pathogenesis, and the possibility exists that these microbiome alterations could contribute directly to the inflammatory environments necessary for the carcinogenesis or atopy involved in these conditions. RECENT FINDINGS: The native esophageal microbiome is similar in composition to the oral microbiome, with a high relative abundance of the phylum Firmicutes and the genus Streptococcus. Limited studies to date suggest that there are certain microbiome alterations associated with esophageal diseases. Additionally, it may be possible to indirectly assess the esophageal microbiome via non-endoscopic means. This raises the possibility that non-invasive microbiome analysis could be used for disease screening and monitoring. SUMMARY: Further understanding of the role of the esophageal microbiome in disease pathogenesis, as well as methods for microbiome alteration may help elucidate future targets for disease modifying therapies, or minimally invasive screening tools in patients at high risk for development of various esophageal conditions.