Characterization of high-vitamin B6 producing probiotics from human milk

BACKGROUND: The objective of this study is to screen high-yield vitamin B6 (VB6) probiotic strains from human milk and explore their probiotic properties and application potential in functional fermented milk. METHODS: A total of ten probiotic strains were isolated from human milk and subsequently cultured in MRS broth to compare their VB6 production capacity. The superior strain was identified via 16S rRNA sequencing, and its tolerance, aggregation, survival rate, and antioxidant properties were determined. The fermentation conditions were optimized, and the quality of the fermented milk was evaluated. It demonstrated adequate gastrointestinal tolerance, aggregation ability, and antioxidant activity. Under optimal fermentation conditions, the maximum VB6 yield reached 5.17 μg/mL. The total phenol content and antioxidant capacity of fermented milk were significantly enhanced, with increases ranging from 5.2-fold to 4-12.9-fold compared to raw milk. Strain XY15 is a promising probiotic strain, exhibiting high levels of VB6-yield performance. CONCLUSION: The potential applications of this strain are significant, particularly in the development of VB6-enriched functional fermented milk. The provision of reliable strain resources and technical support for related product development is a key benefit.