Effects of gut microbiota and metabolites on the host defense peptide expression.

The widespread use of antibiotics has led to the emergence of multidrug-resistant bacteria, which pose significant threats to animal health and food safety. Host defense peptides (HDPs) have emerged as promising alternatives because of their unique antimicrobial properties and minimal resistance induction. However, the high costs associated with HDP production and incorporation into animal management practices hinder their widespread application.

Human cathelicidin LL-37 exerts amelioration effects against EHEC O157:H7 infection regarding inflammation, enteric dysbacteriosis, and impairment of gut barrier function.

Enterohaemorrhagic Escherichia coli (EHEC) O157:H7 infection impairs intestinal barrier function, causing intestinal inflammation and enteric dysbacteriosis. The human cathelicidin LL-37 can regulate excessive inflammatory responses, barrier function, and balance the intestinal microbial community; however, little is known about its effects on inflammation, intestinal barrier function, and microbiota disorders in EHEC O157:H7-infected mice. In this study, we investigated the protective effect of LL-37 against EHEC O157:H7 infection and elucidated the underlying mechanism using a mouse model.