Genomic level reveals potential probiotic properties of Lentilactobacillus kefiri

Lentilactobacillus kefiri (L. kefiri) is one of the common Lactobacillus strains in kefir and other fermented milk products. Evaluation of probiotic indicators in vitro showed that Lactobacillus kefiri NM119-2 has strong acid and bile salt tolerance, with a survival rate of 67.55% after 3 hours in gastric juice at pH 2.5 and 95.79% survival after 4 hours in 0.3% bile salt. It is sensitive to six common antibiotics, including chloramphenicol, penicillin, and ciprofloxacin. L. kefiri NM119-2 is a highly hydrophobic strain with over 40% auto-aggregation capacity. Its overall antioxidant ability is relatively strong, with DPPH radical scavenging at 97.91%, hydroxyl radical scavenging at 52.2%, and superoxide anion scavenging at 27.81%. Additionally, this strain exhibits cholesterol degradation capability. Based on these phenotypic results, further research on the relationship between genes and probiotic functions at the genetic level is warranted.