Departments of Medicine and Pathology, New York University School of Medicine, 423 East 23rd Street, New York, United States of America
For unclear reasons, the incidence of esophageal adenocarcinoma (EA) has risen more than 600% in the United States since the 1970s. Although specific host factors might predispose one to disease risk, such a rapid increase in incidence must be predominantly environmental. The widespread use of antibiotics since 1950s could have contributed to this drastic change. Although not directed at H. pylori, antibiotic exposure prior to 1980s could unintentionally eradicate H. pylori leading to the observed increase in EA. Obesity has had a drastic increase in prevalence since 1970s, similar to EA in trend. Both human and animal studies suggest that exposure to antibiotics changes the colonic microbiome in favour of gaining body weight. Antibiotic use could also have altered the microbiome in the distal esophagus. Overall, esophageal diseases tend to be associated with depletion of Gram-positive bacteria and enrichment of Gram-negative bacteria. Microbiome alteration often extended to the mouth and sometimes to the stomach and rectum. The altered microbiome could play a role in the initiation and progression of EA by in situ induction of chronic inflammation and/or activation of carcinogens. Normalization of the microbiome by selected antibiotics and/or probiotics could become a new way for prevention of EA.