Alleviating effects and mechanism of Lacticaseibacillus paracasei BHP06 on the allergic reactions induced by ovalbumin

Abstract

Food allergy (FA) has caused significant impacts on patients' quality of life. This study comprehensively investigated the therapeutic and prophylactic effects of Lacticaseibacillus paracasei BHP06 on an ovalbumin (OVA)-induced allergy model, while elucidating its immunomodulatory mechanisms. The results showed that compared with the model group, mice in high-dose prophylaxis group (PH6 group) exhibited lower clinical scores for allergic symptoms and decreased levels of OVA-specific IgE (OVA-sIgE), OVA-sIgG1, histamine, mouse mast cell protease (mMCP) 1, and interleukin (IL) 4 by 52.00%, 54.43%, 18.82%, 6.48%, and 29.04%, respectively. Meanwhile, the PH6 group demonstrated significant mitigation of jejunal inflammation, and decrease in the number of mast cells in the intestines of mice. In addition, oral administration of L. paracasei BHP06 maintained immune organ homeostasis in allergic mice, decreased gene expression of IL-4, TNF-α, and GATA-3 in the spleen, increased gene expression of IL-10, T-bet, Foxp3, and TGF-β, and modulated the expression of genes associated with the TLR4/NF-κB signaling pathway. 16S rDNA sequencing analysis revealed that the intake of L. paracasei BHP06 enhanced the ratio of Firmicutes/Bacteroidota in the gut, leading to significant alterations in the diversity. In summary, oral administration of L. paracasei BHP06 exhibited multiple beneficial effects in alleviating FA by regulating immune balance, intestinal inflammation, TLR4/NF-κB signaling pathway, and intestinal flora. Additionally, the preventive intervention strategy using L. paracasei BHP06 demonstrates a more comprehensive and stable effect. These findings suggested the potential development of L. paracasei BHP06 as a functional food for the prevention and management of FA.