Abstract: The in vivo and in vitro safety and probiotic properties of Lactobacillus gasseri LGZ 1029, isolated from the intestinal tract of a 1-month-old baby in Guangzhou and identified by molecular biology methods were evaluated. The results showed that L. gasseri LGZ 1029 did not produce hemolytic toxin, and was sensitive to many kinds of antibiotics. It had no acute oral toxicity to mice and had good gastrointestinal tolerance and self-aggregation capacity. Its hydrophobicity (79.75%) was stronger than that (43.01%) of the commercial standard strain L. rhamnosus ATCC 7469. The diameter of inhibition zone of Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 12598 when exposed to L. gasseri LGZ1029 was 17.31–20.70 and 21.71–31.08 mm, respectively, and the inhibitory effect was stronger than L. rhamnosus ATCC 7469. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of 1 × 107 CFU/mL L. gasseri LGZ 1029 was determined as 87.07%. These results may provide a theoretical basis for the application of L. gasseri LGZ 1029 in dietary supplements and dairy products manufacturing and its application as a bioprotective agent.

Key words: Lactobacillus gasseri; intestinal tract of infants; safety; probiotic properties