Screening of Probiotic Lactic Acid Bacteria from Naturally Fermented Vegetable Products of Sikkim, India

Sinki and gundruk are spontaneously fermented vegetable products traditional to the Himalayan communities in Sikkim, India. This study focused on examining the role of lactic acid bacteria (LAB) obtained from sinki and gundruk as possible probiotic candidates. Eight LAB isolates were selected based on 16S rRNA gene sequencing, with four identified as Levilactobacillus brevis from sinki and three Levilactobacillus brevis and one Lactiplantibacillus plantarum from gundruk. The probiotic potential of all isolates was assessed through in vitro tests and genetic screening for probiotic-related genes. The LAB isolates from both sinki and gundruk showed good survival rates under simulated digestion conditions in the in vitro digestion model. Genetic analysis indicated the presence of marker genes (groEL, tdc, ir1584, apf, fbp, mub1, and plnEF) associated with probiotic traits. According to the PCA-biplot analysis of probiotic qualities based on in vitro tests and genetic screening, L. brevis S2-4 (from sinki) and L. brevis 4AG4 (from gundruk) were identified as the most promising potential probiotic strains.