Abstract:Lactic acid bacteria were isolated from Allium macrostemon in different regions，and the strains were screened and identified；the probiotic functions of the screened strains were evaluated.The results showed that a total of 173 Gram-positive strains were isolated and screened，and their cholesterol-lowering，acid-resistant，and bile salt-resistant abilities were evaluated in vitro. Among them，strains HBXB-19，GZXB-22，GZXB-28，and JXXB-18 had good performance，and their cholesterol degradation rates were all greater than 50%.The survival rates after 4 h treatment in pH2 solution were all greater than 90%，and the survival rates after 4 h treatment in solution containing 0.3% bovine bile salt were all greater than 70%. The 16S rRNA sequence analysis showed that the four strains were all Lactiplantibacillus plantarum. The results of probiotic function evaluation of the four strains showed that the growth performance of strain GZXB-28 was the best，and the absorbance at 600 nm reached 2.485 after 24 h of culture. Strain GZXB-28 had good tolerance to gastrointestinal fluid. The survival rates of strain GZXB-28 was 80.85% after 2 h treatment in artificial gastric fluid and 55.60% after 2 h treatment in artificial intestinal fluid. Strains GZXB-22 and GZXB-28 had strong hydrophobicity，with hydrophobicity of 46.28% and 54.64%，respectively. Strains GZXB-28 and JXXB-18 had strong self-aggregation，with self-aggregation of 58.32% and 62.43%，respectively. Strains GZXB-22，GZXB-28，and JXXB-18 all had inhibitory effects on four pathogenic bacteria. Among them，strain GZXB-22 had the strongest inhibitory effect on Salmonella C79-13 and Bacillus cereus ATCC 14579，and strain GZXB-28 had the strongest inhibitory effect on Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922.The four strains were all intolerant to penicillin，ampicillin，erythromycin，tetracycline，vancomycin，chloramphenicol，amoxicillin，and cefazolin，and the safety was good.In summary，Lactobacillus plantarum GZXB-28 had excellent properties and could be used as a potential strain for the development of new cholesterol-lowering products.