Antimicrobial host defense in the upper gastrointestinal tract

Aims: With the exception of fungi, microbial infections are rare in the esophagus. Herein, we aimed to systematically assess the distribution and quantity of different antimicrobial host factors as well as, for the first time, functional mucosal antimicrobial activity in the upper gastrointestinal tract. Methods: We investigated biopsies from the healthy esophagus, 3 different locations in the stomach and the duodenum in a total of 32 individuals. Using real-time-PCR with external standards, we compared absolute expression of mRNA encoding antimicrobial peptides including defensins, cathelicidin, bactericidal/pe…