Immune function in mice enhanced by lamb soup colloidal nanoparticles: Plasma immune, metabolomics, signaling pathways.

Colloidal nanoparticles (CNPs) are the main form of nutrients in soup products. Lamb soup has the efficacy of improving immunity, benefiting qi and tonifying the kidney. However, its immune mechanism remains unclear. In this study, BALB/c mice were constructed in normal control, prevention (P), model, cyclophosphamide immunodeficiency (CTX) and qi deficiency syndrome (QDS) groups. 18 mice were used for 7-d acclimitization and 5-d intraperitoneal injection modeling. After that, 3 mice were put to death to evaluate the modeling, and 15 mice were used for subsequent detection indicators. The less body weight, shorter exhaustion swimming time, lower organ index and lower plasma immunoglobulin content indicated that the CTX and QDS mouse models were successfully established. Results indicated that CNPs contributed to the weight gain as well as repaired the injury of the spleen and thymus in mice. Plasma immunity indices revealed that CNPs increased the immunoglobulin content of mice in the P, CTX, and QDS groups, thereby improving their immunity. Combined with metabolomics and KEGG database, GnRH, cAMP, Neurotrophin and PI3K-Akt signaling pathways were the key signaling pathways of lamb soup CNPs to enhance mice's immunity. This study aimed to provide a theoretical foundation for lamb soup to enhance immune function.