Esophageal Dysbiosis in Achalasia and Cancer Development: A Critical Review

Background: Microorganisms provide various benefits to their human hosts, including assisting with digestion, synthesizing certain vitamins, developing the gastrointestinal and immune systems, regulating metabolism, and protecting against some pathogens. However, microbial imbalances can cause tissue damage and contribute to inflammatory disorders and cancers. Microbial dysbiosis refers to an imbalance or disruption in the normal composition and function of the microbial communities that inhabit various body parts, including the gut, oral cavity, skin, and reproductive tract. Emerging research suggests that microbial dysbiosis plays a significant role in cancer development and progression. This issue is particularly relevant in achalasia, in which food stasis, changes in endoluminal pH, and poor esophageal clearance might contribute to esophageal microbial dysbiosis. This study aimed to evaluate the association between dysbiosis and esophageal cancer development, focused on esophageal dysmotility disorders. Methods: This study is a critical review, gathering the current evidence for the association between dysbiosis and the development of esophageal cancer. Results: Studies have shown that microbiota play a role in cancer development, although the mechanisms for how they do so are not yet fully understood. One possible explanation is that microbiota alterations can lead to chronic inflammation, promoting cancer cell growth. Additionally, some bacteria produce toxins that can damage DNA and cause genomic instability, and certain bacterial products can promote tumor growth. Conclusion: Despite the close relationship between dysbiosis and cancer development in esophageal dysmotility disorders, further investigations are still needed to elucidate the precise mechanisms by which dysbiosis contributes to cancer development and to identify potential therapeutic interventions targeting the microbiota to prevent or treat cancer.