Dietary Lysozyme Effects on Animal Growth and Gut Health

Dietary lysozyme, an antimicrobial enzyme naturally present in bodily secretions such as milk and tears, has emerged as a multifunctional feed additive in livestock production. When incorporated into diets, lysozyme exhibits bacteriolytic activity against a range of Gram-positive and, to a lesser extent, Gram-negative pathogens. Beyond direct antimicrobial effects, it modulates the composition and metabolic activity of the gut microbiota, supporting a more favourable community of bacteria that contribute to nutrient breakdown and barrier integrity. Enhanced gut morphology—characterised by increased villus height and optimised crypt architecture—facilitates nutrient absorption, while immunomodulatory properties of lysozyme reduce intestinal inflammation under challenge. These combined effects lead to improvements in growth performance metrics such as body weight gain and feed conversion ratio across poultry, swine and other monogastric species. As concerns mount over antibiotic resistance, lysozyme offers a natural alternative to subtherapeutic antimicrobials, helping to safeguard animal health, productivity and food security on a global scale.

Research from Nature Portfolio

A multi-omics study in broiler chickens evaluated a dietary muramidase—an enzyme functionally analogous to lysozyme—at low and high inclusion levels over a 42-day trial. High-dose supplementation yielded superior feed conversion ratio and increased final body weight compared with control. Caecal microbiota analyses revealed reduced alpha diversity alongside a shift from Firmicutes towards Bacteroidetes and an enrichment of Lactobacillaceae at higher enzyme doses. Concurrent metabolomic profiling indicated alterations in systemic metabolites, including elevated pyruvate and 2-oxoglutarate levels, suggesting enhanced energy metabolism. By integrating microbial, transcriptomic and metabolic data, this work illuminates the mechanistic pathways through which dietary muramidase optimises gut ecology and host performance, laying groundwork for targeted enzyme-based interventions in poultry nutrition.

Dietary Lysozyme Effects on Animal Growth and Gut Health publication trend

The graph below shows the total number of articles in dietary lysozyme effects on animal growth and gut health across all publications each year (not limited to Nature Index journals).

Technical terms

Lysozyme: A naturally occurring enzyme that cleaves bacterial cell-wall peptidoglycan, used in feed to control pathogens and modulate gut ecology.

Muramidase: An enzyme similar to lysozyme derived from microbial sources, employed in diets to enhance gut health and nutrient utilisation.

Feed conversion ratio (FCR): The amount of feed required to produce a unit of body mass gain; lower values indicate more efficient growth.

Gut microbiota: The complex community of microorganisms residing in the gastrointestinal tract, crucial for digestion, immunity and barrier function.

Villi and crypts: Finger-like projections (villi) and invaginations (crypts) in the intestinal lining that determine absorptive surface area and epithelial renewal, respectively.

References

1. Exogenous dietary lysozyme improves the growth performance and gut microbiota in broiler chickens targeting the antioxidant and non-specific immunity mRNA expression. PLOS ONE (2017).
2. Lysozyme improves gut performance and protects against enterotoxigenic Escherichia coli infection in neonatal piglets. Veterinary Research (2018).
3. Lysozyme as an alternative to growth promoting antibiotics in swine production. Journal of Animal Science and Biotechnology (2015).
4. A multi-omics approach to elucidate the mechanisms of action of a dietary muramidase administered to broiler chickens. Scientific Reports (2022).