In Vitro Probiotic Properties of Human-derived Lactiplantibacillus plantarum in Yining, Xinjiang

Lactiplantibacillus plantarum is widely distributed in nature and is one of the most widely developed and used lactic acid bacteria species at present. Most developed and used L. plantarum are derived from fermented food or plant-based materials. In this study, L. plantarum was isolated from fecal samples of healthy Uyghur and Kazakh children in Yining, Xinjiang, and 20 representative strains were selected by fingerprinting to remove the identical bands. The clustering results of fingerprinting classified the strains into three major groups, and strains of the same ethnicity and age group were more likely to be clustered in the same small branch. The phylogenetic tree based on groEL gene showed that strains of the same ethnic origin tended to cluster together. At the same time, the acid and bile salt tolerance, self-aggregation, hydrophobicity (xylene), bacteriostatic capacity, antibiotic sensitivity and carbohydrate utilization ability of 20 strains were tested in vitro. The results showed that strains YLW2L-108-29, YLW2L-61-7 and YLW1L-44-7 had better acid (pH2.5) resistance, and YLW1L-44-6 had the best bile salt tolerance (0.3% concentration). Strains YLW2L-61-7, YLW2L-57-4, YLW2L-66-30 had the best self-aggregation and hydrophobics results, and all strains grew well on fructooligosaccharide, galactooligosaccharide, isomaltooligosaccharide, maltodextrin, raffinose, D-(+)-trehalose dihydrate, pectin, stachyose tetrahydrate and soybean oligosaccharide. Most strains had poor growth on inulin and resistant starch, and worst growth on xylo-oligosaccharide. Combined with the results of bacterial inhibition and antibiotic resistance, strain YLW2L-61-7 was screened as a potential probiotic strain for subsequent studies, laying the foundation for the development of excellent probiotic strains and products suitable to regional populations.