Extensive genomic characterization, pre-clinical probiotic evaluation, and safety analysis of Bifidobacterium longum subsp. longum BL21 isolated from infant feces.

2024-12
Microbial pathogenesis 197

PubMed: 39505088
DOI: 10.1016/j.micpath.2024.107100

Study Design

Population: Bifidobacterium longum subsp. longum BL21 isolated from infant feces
Methods: Whole-genome sequencing; physiological and biochemical assessments; enzymatic assays; metabolite, antibiotic sensitivity, cell adhesion and cytotoxicity, and tolerance tests; and a 14-day oral toxicity study

Objective

This study aimed to evaluate the safety and probiotic properties of Bifidobacterium longum subsp. longum BL21 isolated from infant feces for use as a commercial probiotic strain.

Methods

Whole-genome sequencing; physiological and biochemical assessments; enzymatic assays; metabolite, antibiotic sensitivity, cell adhesion and cytotoxicity, and tolerance tests; and a 14-day oral toxicity study were conducted.

Results

BL21 exhibited genetic integrity, and its genome lacked genes related to antibiotic resistance or virulence. It was found to be non-pathogenic, had efficient carbohydrate metabolism and mucin degradation ability, and was free from biogenic amines. It also showed susceptibility to antibiotics, strong cell adhesion, and resilience to adverse conditions. The aforementioned results confirm that BL21 is a functional probiotic strain with genetic stability, enzymatic capabilities, and non-pathogenic properties that mean it is safe for oral consumption, demonstrating that it is a promising candidate for probiotic applications.

Conclusion

The study demonstrates that BL21 is a genetically stable, non-pathogenic probiotic strain with metabolic potential. The strain lacks virulence and antibiotic resistance genes, and its resilience to gastrointestinal conditions, as well as the results of the 14-day oral toxicity study, suggest that BL21 is safe for oral consumption. However, further long-term studies and clinical trials are needed to confirm its safety and efficacy for therapeutic use.

Research Insights

Supplement	Dose	Health Outcome	Effect Type	Effect Size	Source
Bifidobacterium longum subsp. longum	—	Enhanced Gastrointestinal Stress Resistance	Beneficial	Small	View source resilience to adverse conditions... its resilience to gastrointestinal conditions... suggest that BL21 is safe for oral consumption
Bifidobacterium longum subsp. longum	—	Reduced Toxicity	Beneficial	Moderate	View source the results of the 14-day oral toxicity study, suggest that BL21 is safe for oral consumption