Microbiological quality assessment oral probiotics in Ho Chi Minh city

Introduction: The global probiotic market continues to expand, yet concerns about product quality persist, particularly regarding mismatches between labeled and actual probiotic content. Assessing the microbiological quality of probiotic pharmaceuticals and supplements in Ho Chi Minh City is crucial to reflect market status and guide quality control. Methods: Species identity was confirmed by PCR and sequencing. Viable counts were measured by the plate count method at baseline and after 3 months. Key probiotic traits were evaluated following FAO/WHO (2001) guidelines, including tolerance to simulated gastrointestinal conditions, antimicrobial activity against enteric pathogens, and antibiotic susceptibility via broth microdilution. Results: Of 26 products tested, 18 initially matched label claims for viable count. After 3 months of storage, there was a gradual decrease in viable count, especially among those containing Lactobacillus spp. and Saccharomyces spp., which decreased the number of compliant products to 15. Species mislabeling occurred in 7 products (26.9%), including 3 contained fewer species than claimed, 1 had mismatched species identification, and 3 contained additional species that were not listed on the label. Bacillus spp. showed superior survival rate under acidic and bile salt conditions, while Lactobacillus spp. exhibited the strongest antimicrobial activity. Most strains were antibiotic-susceptible, except some Bacillus spp., displaying minor non-susceptibility to clindamycin. Conclusions: Discrepancies between the labeled and actual probiotic content, both in quantity and species, remain a major challenge for ensuring product reliability and rational use.