Esophageal dysbiosis and pathogenesis of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is a condition of symptoms or pathologic changes associated with the retrograde flow of gastric contents into the esophagus (Tack and Pandolfino [1]). While some extent of gastroesophageal reflux may be normal, symptoms caused by increased acid exposure and/or the presence of mucosal injury point toward GERD (Tack and Pandolfino [1]). With the advent of newer tools to characterize the gut microbiome, understanding of factors that contribute to esophageal disease has expanded, and it has become clear that the local flora plays a significant role. In this chapter, we discuss the evolving changes in the understanding of the pathogenesis of GERD.