Abundant data has now shown that natural plant polysaccharides can be used as substitutes for antibiotic growth promoters in animal production, and significantly improve respiratory health.
Licorice
Glycyrrhiza polysaccharides (GPS) are compounds extracted from licorice roots. They are complex structures composed of various types and proportions of sugar residues, such as glucose, arabinose, rhamnose, and xylose. These polysaccharides have attracted increasing interest for their positive effects on immune modulation and for their anti-inflammatory, antioxidant, antiviral, and antibacterial effects.
While previous studies have highlighted the benefits of GPS in promoting broiler growth, their potential impact on respiratory health remains underexplored. Therefore, a recent Chinese study aimed to evaluate the effects of GPS supplementation on broiler growth performance, respiratory barrier function, lung microbiota, lung transcriptomics and serum metabolomics.
The study
240 male day-old chickens were randomly assigned to two groups: basal diet (CON) and GPS (supplemented with 150 mg/kg Glycyrrhiza polysaccharides). Compared with the CON group, the GPS group significantly increased broiler chickens’ average daily weight, serum immunoglobulins A, M and G, antioxidant capacity, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and tracheal messenger RNA (mRNA) expression levels of SOD1, SOD2 and GSH-Px. The GPS group also had increased food conversion efficiency, decreased lung levels of IL-1β and IL-6, and increased tracheal mRNA expression of occludin, claudin1 and mucin-2.
In addition, the GPS group had alterations in lung microbial diversity and composition.
Transcriptomic and metabolomic analyses revealed activation of the T-cell receptor (TCR) signaling pathway and the linoleic acid metabolic pathway in the GPS group. Correlation analysis demonstrated significant associations between differential bacteria, genes, serum metabolites and phenotypic indicators.
This study showed that the addition of GPS can modulate the lung microbiota, activate the TCR signaling pathway, and thereby influence the linoleic acid metabolism pathway. This process improves antioxidant capacity, immune function and respiratory tract barrier function, ultimately improving respiratory health and promoting improved growth performance of broiler chickens.
Reference
Yingying Qiao, Yongpeng Guo, Xinlei Wang, Wei Zhang, Weibing Guo, Zhixiang Wang, Changzhong Liu, Multi-omics analysis reveals the enhancing effects of Glycyrrhiza polysaccharides on the respiratory health of broilers, International Journal of Biological Macromolecules, Volume 280, Part 3, 2024, 135953, ISSN 0141-8130, https://doi.org/10.1016/j.ijbiomac.2024.135953
