Screening and identification of lactic acid bacteria with potential anti-allergic activity

Allergic disease is a common disease that harms human health and seriously harms patients' normal life. To screen lactic acid bacteria with potential anti-allergic properties. Isolation and identification of lactic acid bacteria from traditional fermented foods by MRS-CaCO₃ plate calcium solubilization and 16S rDNA. The probiotic properties of the strains were determined, including growth performance, acid production, gastrointestinal fluid tolerance, adhesion (co-aggregation, self-aggregation and hydrophobicity), and hyaluronidase inhibition. On this basis, the anti-allergic potential of the strains was determined by establishing a lipopolysaccharide-induced RAW246.7 cell model. The results of the study showed that five strains of lactic acid bacteria were initially isolated and identified as Lactobacillus fermentum 2, Lactiplantibacillus plantarum 14, Latilactobacillus curvatus 27, Lactiplantibacillus plantarum 32 and Lentilactobacillus parabuchneri 138. Except for strain 27, the remaining strains had a high capacity for acid production and growth. Strains 14 and 32 were highly acid-producing and could reach a pH of 3.88, while strain 138 had the strongest growth capacity. All strains showed high tolerance to simulated gastric fluid, with strains 14 and 138 being significantly more tolerant than the positive control Lactobacillus rhamnosus GG (LGG). Strain 14 has the best self-aggregating ability. Strain 14 and 138 had better hydrophobicity towards ethyl acetate, which was significantly higher than that of LGG. This indicates that the strain has good adhesion properties. All strains had similar co-aggregation ability for Escherichia coli and Staphylococcus aureus. Moreover, all strains had high hyaluronidase inhibition rates (> 70%) and significantly inhibited nitric oxide (NO) production in lipopolysaccharide-induced RAW246.7 cells, indicating their potential anti-allergic potential. In addition, the strains all have good antibiotic sensitivity and are strongly susceptible to ampicillin, erythromycin, chloramphenicol, and tetracycline. Hemolytic activity was not detected. In brief, Lactiplantibacillus plantarum 14 and Lentilactobacillus parabuchneri 138 have potential anti-allergic activity. The results of this study provide a certain theoretical basis for the screening of anti-allergic probiotics and help the development and comprehensive utilization of strains.