Pan-genome evolution and its association with divergence of metabolic functions in Bifidobacterium genus

Many works have been performed to characterize the genomic evolution and diversity among type species of the Bifidobacterium genus due to its health-promoting effect on their host. However, those studies were mainly based on species-level taxonomic resolution, adaptation, and characterization of carbohydrate metabolic features of the bifidobacterial species. Here, a comprehensive analysis of the type strain genome unveils the association of pan-genome evolution with the divergence of metabolic function of the Bifidobacterium genus. This study also has demonstrated that the horizontal gene transfer and genome expansion and reduction events in the evolutionary history influencing the diversity of metabolic functions of bifidobacterium genus. Furthermore, the genome-based search of probiotic traits among all the available bifidobacterial type strains gives hints on type species, that could confer health benefits to nutrient-deficient individuals. Altogether, the present study provides insight into the developments of genomic evolution, functional divergence, and potential probiotic type species of the Bifidobacterium genus.