Opinion Review
Copyright ©The Author(s) 2019.
World J Gastroenterol. May 14, 2019; 25(18): 2149-2161
Published online May 14, 2019. doi: 10.3748/wjg.v25.i18.2149
Table 1 Esophageal microbiota studies on Barrett's esophagus and esophageal adenocarcinoma
Publication yearSample populationSequencing approachRelated notable findingsRef
2004Four patients with normal esophagus16S rDNA1 Members of six phyla, Firmicutes, Bacteroides, Actinobacteria, Proteobacteria, Fusobacteria, and TM7, were represented.[32]
2 Streptococcus (39%), Prevotella (17%), and Veilonella (14%) were most prevalent.
2007Seven subjects without BE and seven patients with BE16S rRNACampylobacter colonized the esophagus in the majority of BE patients and could not be identified in the control group.[35]
2009Thirty-four patients with normal, esophagitis, or Barrett's esophagus16S rRNA1 Esophageal microbiomes can be classified into two types.[33]
2 The type I microbiome was mainly composed of gram-positive bacteria, dominated by the genus Streptococcus and concentrated in the phenotypically normal esophagus.
3 The type II microbiome contained a greater proportion of gram-negative anaerobes/microaerophiles and primarily correlated with esophagitis (Odds Ratio: 15.4) and BE (Odds Ratio: 16.5).
2012Fifteen subjects16S rRNAThe compositions of the esophageal microbiota were similar between the traditional biopsy and the overnight esophageal string test.[52]
2014Thirteen patients with esophagitis, six patients with BE, fifteen normal controls16S rRNAThe Enterobacteriaceae family (mainly the genus Escherichia) is associated with esophageal abnormalities, such as esophagitis and BE.[36]
2015Twelve participants enrolled in the Seattle Barrett's Esophagus Research Program16S rRNA1 Streptococcus and Prevotella species dominate the upper GI and the ratio of these two species is associated with waist-to-hip ratio and hiatal hernia length, two known EAC risk factors in Barrett’s esophagus.[27]
2 Mucosal brush samples enhanced the detection of bacterial diversity in the esophagus and stomach, and the microbiota compositions were similar after replicate sampling.
2017Twenty normal controls, twenty-four non- dysplastic BE twenty-three dysplastic BE16S rRNA1 The microbial diversity in the esophagus is decreased in EAC patients, regardless of the exact sampling locations.[12]
2 Lactobacillus fermentum was enriched in EAC patients, and lactic acid bacteria dominated and affected the microenvironment.
2018Twenty-seven dental and esophageal disease-free individuals16S rRNA1 The phyla Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria, Fusobacteria, and TM7 were most abundant in both the oral cavity and the esophagus.[28]
2 The genera Streptococcus, Neisseria, Prevotella, Actinobacillus, and Veillonella were most abundant in both oral cavity and esophagus, and Streptococcus in the esophagus.
3 No site-specific bacteria were found for three different segments (upper, middle, and lower) of the esophagus.