Article Sharing | β-Defensins: Microbiota Regulators for Maintaining Homeostasis and Health — Abstract

β-Defensins: Microbiota Regulators for Maintaining Homeostasis and Health — Abstract

Commensal microbial communities are now recognized as essential for maintaining physiological homeostasis and preventing disease. While bacteria are the most extensively studied and abundant members of the microbiome, it also includes less understood communities of viruses, fungi, archaea, and protozoa.

Host defense peptides (HDPs), originally characterized as antimicrobial peptides, are now increasingly recognized as key regulators of microbiome diversity, microbial load, and host homeostasis. This emerging role has driven a shift away from nonspecific antibiotic-based microbial elimination strategies, particularly in veterinary applications.

β-Defensins, one of the evolutionarily conserved families of HDPs, are multifunctional cationic peptides produced by epithelial and immune cells in various forms. They play a central role in regulating host–microbe interactions and maintaining a healthy and dynamic balance across mucosal systems. As such, β-defensins act as critical guardians of the oral cavity, respiratory tract, reproductive tract, and intestinal tissues, protecting against pathogen-associated inflammation while preserving normal physiological conditions.

Recent studies have shown that the increased copy number of β-defensin genes in certain species may have important functional significance. Disruption of β-defensin expression during prenatal development may impair neonatal immune programming, thereby increasing susceptibility to disease later in life.

This article reviews recent findings highlighting the pivotal role of β-defensins in shaping complex prokaryotic ecosystems across body surfaces and cavities. It also discusses new perspectives on β-defensins as sensors of homeostasis and key mediators of innate immunity.