Related Experiment Video
Updated: Jun 25, 2026
Production of Germ-Free Fast-Growing Broilers from a Commercial Line for Microbiota Studies
Published on: June 18, 2020
Effect of oral administration of microcin Y on growth performance, intestinal barrier function and gut microbiota of
Wenjing Li1, Zhiwei Zeng1, Di Zhou1
1College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.
Abstract:
The lasso peptide microcin Y (MccY) effectively inhibits various serotypes of Salmonella in vitro, but the antibacterial effect against S. Pullorum in poultry is still unclear. This study was the first to evaluate the safety and anti-S. Pullorum infection of MccY in specific pathogen-free (SPF) chicks. The safety test showed that the body weight, IgA and IgM levels of serum, and cecal microbiota structure of 3 groups of chicks orally administrated with different doses of MccY (5 mg/kg, 10 mg/kg, 20 mg/kg) for 14 days were not significantly different from those of the control group. Then, the chicks were randomized into 3 groups for the experiment of anti-S. Pullorum infection: (I) negative control group (NC), (II) S. Pullorum-challenged group (SP, 5 × 108 CFU/bird), (III) MccY-treated group (MccY, 20 mg/kg). The results indicated that compared to the SP group, treatment of MccY increased body weight and average daily gain (P < 0.05), reduced S. Pullorum burden in feces, liver, and cecum (P < 0.05), enhanced the thymus, and decreased the spleen and liver index (P < 0.05). Additionally, MccY increased the jejunal villus height, lowered the jejunal and ileal crypt depth (P < 0.05), and upregulated the expression of IL-4, IL-10, ZO-1 in the jejunum and ileum, as well as CLDN-1 in the jejunum (P < 0.05) compared to the SP group. Furthermore, MccY increased probiotic flora (Barnesiella, etc.), while decreasing (P < 0.05) the relative abundance of pathogenic flora (Escherichia and Salmonella, etc.) compared to the SP group.
Insights
Microcin Y (MccY) is safe for chicks and effectively combats Salmonella Pullorum infection. This study shows MccY improves chick growth, reduces bacterial load, and enhances gut health by modulating microbiota.
Area of Science:
- Veterinary Microbiology
- Animal Science
- Peptide Therapeutics
Background:
- Salmonella Pullorum causes significant economic losses in poultry farming.
- Microcin Y (MccY), a lasso peptide, shows in vitro efficacy against Salmonella but its in vivo effect in poultry is unknown.
- Specific pathogen-free (SPF) chicks are a suitable model for evaluating MccY's safety and efficacy.
Purpose of the Study:
- To evaluate the safety of Microcin Y (MccY) in specific pathogen-free (SPF) chicks.
- To assess the efficacy of MccY against Salmonella Pullorum infection in poultry.
- To investigate MccY's impact on chick growth, gut health, immune response, and cecal microbiota.
Main Methods:
- Safety assessment involved oral administration of MccY at varying doses (5-20 mg/kg) to SPF chicks for 14 days, monitoring body weight, serum IgA/IgM, and cecal microbiota.
- Efficacy study involved challenging chicks with Salmonella Pullorum (5 × 10^8 CFU/bird) and treating with MccY (20 mg/kg).
- Parameters measured included body weight, average daily gain, Salmonella burden, organ indices, jejunal morphology, gene expression (IL-4, IL-10, ZO-1, CLDN-1), and cecal microbiota composition.
Main Results:
- MccY administration did not cause significant adverse effects on chick body weight, serum immunoglobulin levels, or cecal microbiota structure.
- MccY treatment significantly increased body weight and average daily gain in S. Pullorum-challenged chicks.
- MccY reduced Salmonella Pullorum burden in feces, liver, and cecum, enhanced thymus, and modulated spleen/liver indices.
- Histological analysis revealed increased jejunal villus height and decreased crypt depth in MccY-treated chicks.
- MccY upregulated key immune and tight junction genes (IL-4, IL-10, ZO-1, CLDN-1) in the jejunum and ileum.
- MccY treatment promoted beneficial bacteria (e.g., Barnesiella) and suppressed pathogenic bacteria (e.g., Escherichia, Salmonella) in the cecum.
Conclusions:
- Microcin Y (MccY) is safe for SPF chicks at the tested dosages.
- MccY demonstrates significant therapeutic potential against Salmonella Pullorum infection in poultry.
- MccY enhances host immunity, improves gut barrier function, and rebalances the gut microbiota, contributing to its anti-Salmonella effects.
