Recombinant lactobacillin PlnK adjusts the gut microbiome distribution in broilers.

Area of Science:

• Microbiology
• Immunology
• Animal Science

Background:

• The biological functions of Lactobacillus bacteriocin plantaricin K (PlnK) are not well understood.
• Investigating PlnK's properties can reveal novel antimicrobial and immunomodulatory applications.

Purpose of the Study:

• To achieve heterologous expression of PlnK in E. coli.
• To determine the antibacterial spectrum of recombinant PlnK.
• To evaluate the effects of PlnK on the gut microbiome and intestinal immunity in broilers.

Main Methods:

• PlnK was expressed in E. coli BL21 using isopropyl β- d-1-thiogalactopyranoside (IPTG) induction.
• The antibacterial activity of PlnK was tested against gram-positive and gram-negative bacteria.
• Broilers were administered PlnK, and their gut microbiome composition and duodenal immune gene expression were analyzed.

Main Results:

• PlnK was efficiently expressed in E. coli and showed inhibitory effects on both gram-positive and gram-negative bacteria at concentrations above 0.10 mg/ml.
• PlnK administration altered the gut microbiome in broilers, increasing Firmicutes and decreasing Bacteroidetes, with specific changes at family and genus levels.
• PlnK did not significantly increase sIgA but reduced mRNA levels of TLR3, MDA5, and interferon-related genes in the broiler duodenum.

Conclusions:

• Recombinant PlnK exhibits broad-spectrum antibacterial activity.
• PlnK can modulate the intestinal microbiome composition in broilers.
• PlnK downregulates key components of the interferon signaling pathway in the broiler gut.