Effects of 2′-fucosyllactose on 2 Bifidobacterium infantis strains: Focus on intraspecific metabolism, environmental tolerance, and adhesion

Human milk oligosaccharides (HMO) play an important role in the growth and development of infants. Some bifidobacteria have been shown to use HMO through conserved and strain-specific pathways and also have shown different physiological characteristics under different carbon sources. Previous studies have concentrated on representative strains of each genus, yet there is a paucity of research on the metabolic and function differences between strains within subspecies. In this work, we compared the differences between Bifidobacterium infantis CICC 6069 and B. infantis Z-081 under glucose, lactose, galactooligosaccharides, and 2'-fucosyllactose (2'-FL), including growth and metabolic, gastrointestinal digestive resistance, and adhesion to Caco-2. Compared with the type strain CICC 6069, B. infantis Z-081 had higher tolerance characteristics under different carbon sources, but its adhesion characteristics were lower than those of CICC 6069. And it was proved that 2'-FL could promote the adhesion of B. infantis. Furthermore, the distinct global gene transcription response was observed among the strains. The results of this study provide a comprehensive understanding of the genomic differences between 2 strains of B. infantis, ideas for the screening of functional probiotics, and further support the potential application of 2'-FL as a prebiotic supplement.