Tumor-Asociated Microbiota in Esophageal Squamous Cell Carcinoma

Background: Human intestinal tract microbiome dysbiosis plays an emerging pivotal role in tumorigenesis of gastrointestinal tract cancers. For esophageal squamous cell carcinoma (ESCC), the esophageal microbiota plays a critical role during the pathogenesis. The microbiome of esophageal can impact its host decades before the onset of ESCC, and can interact with the host’s physiological situation, which are affected by lifestyle factors, including diet, obesity, alcohol and tobacco use, and oral hygiene.Our objective is to analyze the composition of the ESCC-associated microbiota and characterize its contribution to the development of ESCC. The esophageal microbiota was prospectively investigated in 18 patients with ESCC and 11 patients with physiological normal (PN) esophagus by 16S rRNA gene profiling, using next-generation sequencing. Results: The microbiota composition in tumor tissues of ESCC patients is significantly different from that of patients with PN tissues. The ESCC microbiota was characterized by reduced microbial diversity, by decreased abundance of Bacteroidetes, Fusobacteria and Spirochactes. Employing these taxa into a microbial dysbiosis index demonstrated that dysbiosis microbiota had good capacity to discriminate between ESCC and PN esophagus. Functional analysis of the microbiota characterized that ESCC microbiota had altered nitrate reductase and nitrite reductase functions when compared with PN group. The observations were confirmed in other validation cohorts.Conclusions: Detailed analysis of the microbiota of the ESCC patients revealed that tumor exhibit a dysbiotic microbial community when compared with PN groups. We characterized microbial compositional changes, and further identified significant enrichments of Treponema amylovorum, Streptococcus infantis, Prevotella nigrescens, Porphyromonas endodontalis, Veillonella dispar, Aggregatibacter segnis, Prevotella melaninogenica, Prevotella intermedia, Prevotella tannerae, Prevotella nanceiensis and Streptococcus anginosus in ESCC oncogenic progression.Trial registration number: This study was registered at the Chinese Clinical Trial Registry (ChiCTR1800018897). http://www.chictr.org.cn/.