The Esophageal Microbiome in Health and Disease

Abstract

While the esophagus was previously considered devoid of a significant bacterial population, development of culture-independent techniques, specifically 16S rRNA gene sequencing, as well as novel, minimally invasive microbial sampling modalities, has facilitated characterization of the esophageal microbiome in both health and several disease states. Although limited, there is evidence that the esophagus contains a diverse microbial population, with Gram-positive bacteria, specifically Streptococcus, dominating in health, while Gram-negative bacteria prevail in reflux disorders including GERD and Barrett's esophagus. The microbiome is altered with other esophageal disorders as well, including eosinophilic esophagitis and esophageal motility disorders, though these changes have been less well characterized. Characterization of the gut microbiome has advanced significantly; however, further investigation is essential. Understanding changes in the esophageal microbiome could affect our understanding of the natural history of diseases of the esophagus and present potential therapeutic approaches.

The Role of the Cervicovaginal Microbiome on the Genesis and as a Biomarker of Premalignant Cervical Intraepithelial Neoplasia and Invasive Cervical Cancer

“…It was shown that the microbial patterns were different from control samples and, interestingly, the bacterial composition changed according to the affected site [35], suggesting that each gastrointestinal cancer has its own microbial signature. Concerning the esophagus, a shift in its microbiome to a less diverse community with dominance of single bacterial species (such as Campylobacter and Lactobacillus) was correlated with esophageal adenocarcinoma [36]. Further, Helicobacter pylori infection is a recognized risk factor for gastric cancer development, but other species from the gastric microbiome are also being associated with carcinogenesis [37].…”

The Effects of Nutrition on the Gastrointestinal Microbiome of Cats and Dogs: Impact on Health and Disease

“…The composition of the microbiome across the GI tract is not uniform, as qualitatively and quantitatively distinct communities have been identified in each ecological and anatomical niche ( Alarcón et al, 2017 ; Proctor and Relman, 2017 ; Gorkiewicz and Moschen, 2018 ; Yadav et al, 2018 ). Research in pets and humans now recognizes distinct microbiomes in the oral cavity ( Dewhirst et al, 2012 , 2015 ; Davis, 2016 ), esophagus ( Corning et al, 2018 ), and stomach ( Bik et al, 2006 ; Gorkiewicz and Moschen, 2018 ). Even within a single anatomical region, evidence in humans and dogs suggests there may be distinct subpopulations that vary with the terrain and topography of the region, as well pH, oxygen, and nutrient gradients ( Suchodolski et al, 2008 ; Segata et al, 2012 ; Wlodarska et al, 2015 ; Hoffmann et al, 2016 ; Honneffer et al, 2017 ; Proctor and Relman, 2017 ; Gorkiewicz and Moschen, 2018 ).…”

Exploring Esophageal Microbiomes in Esophageal Diseases: A Systematic Review

“…Traditionally, the esophagus is regarded as devoid of a significant bacterial population. 1,2 In addition, microbial flora in a normal esophagus has been considered transient and translocated from the oropharynx. 3 In 1998, Gagliardi et al 3 revealed that Streptococcus viridans is the most commonly found microorganism in esophageal cultures, which is also isolated from oropharyngeal cultures.…”

“…6,7 Additionally, several studies evaluated the microbial composition of a normal esophagus as well as various esophageal diseases such as gastroesophageal reflux disease (GERD), Barrett's esophagus, esophageal cancer, and eosinophilic esophagitis (EoE). 2 Here, we performed a systematic review on the variation in microbial composition according to the esophageal diseases.…”