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Updated: Jun 19, 2026

Quantitative Polymerase Chain Reaction-based Analyses of Murine Intestinal Microbiota After Oral Antibiotic Treatment
Published on: November 17, 2018
Enteric defensins are essential regulators of intestinal microbial ecology
Nita H Salzman1, Kuiechun Hung, Dipica Haribhai
1Division of Gastroenterology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA. nsalzman@mcw.edu
Abstract:
Antimicrobial peptides are important effectors of innate immunity throughout the plant and animal kingdoms. In the mammalian small intestine, Paneth cell alpha-defensins are antimicrobial peptides that contribute to host defense against enteric pathogens. To determine if alpha-defensins also govern intestinal microbial ecology, we analyzed the intestinal microbiota of mice expressing a human alpha-defensin gene (DEFA5) and in mice lacking an enzyme required for the processing of mouse alpha-defensins. In these complementary models, we detected significant alpha-defensin-dependent changes in microbiota composition, but not in total bacterial numbers. Furthermore, DEFA5-expressing mice had striking losses of segmented filamentous bacteria and fewer interleukin 17 (IL-17)-producing lamina propria T cells. Our data ascribe a new homeostatic role to alpha-defensins in regulating the makeup of the commensal microbiota.
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