Probiotic products have attracted increasing attention for their potential to modulate the microbiota. However, most commercial products are designed for oral administration, and their probiotic properties relevant to topical use in the reproductive tract remain insufficiently evaluated. [Objective] To assess the probiotic properties of lactic acid bacteria (LAB) derived from probiotic products, with a particular focus on their potential for topical application, thus providing scientific evidence for their use in vaginal health. [Methods] Seven common oral probiotic products (P1-P7) containing at least two different LAB species were selected from major e-commerce platforms via keyword screening, along with one clinical probiotic product (P8). LAB strains were isolated and identified from these products. We evaluated the acid tolerance, as well as the growth characteristics under different pH conditions, of the isolates by culturing them in the media of varying pH values. The antimicrobial activities of the isolates were determined via co-culture assays with pathogenic microorganisms, while hemolysis assays and genomic comparison were conducted to assess safety. [Results] The isolation rates of LAB strains from P1 to P8 were 50.0% (2/4), 0 (0/4), 66.7% (2/3), 12.5% (1/8), 33.3% (2/6), 40.0% (2/5), 0 (0/7), and 100.0% (1/1), respectively. Most strains grew well at pH 6.0-7.0, and some maintained growth at pH 4.0. Strains P4 and P8 exhibited superior acid tolerance to the others. The inhibitory effects of different strains against common vaginal pathogens varied significantly. Strains P1-2, P5-1, P6-1 and P6-2 demonstrated moderate to strong broad-spectrum inhibitory activity against all tested pathogens. Other isolated strains except P8 exhibited inhibitory activity against Gardnerellavaginalis, while strain P8 showed weak inhibitory activities against the tested pathogens. Strains P4, P5-2, P6-1, and P6-2 achieved inhibition rates exceeding 99.73% against Candidaalbicans across all three tested inoculum concentrations, and strain P5-1 reached an inhibition rate of over 94.64%. None of the strains exhibited β-hemolytic activity, and no antibiotic resistance or virulence genes were detected. [Conclusion] Several LAB isolates from commercial probiotic products exhibited notable inhibitory activities against pathogenic microorganisms and demonstrated good safety profiles. Topical administration may therefore offer greater practical value in promoting female reproductive tract health.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |