Isolation and Characterization of New Probiotic Strains From Chinese Babies

Abstract

The aims of this study were to isolate, to identify, and to characterize new potential probiotic strains from the feces of Chinese neonates. Probiotic strains approved in China for use in infants were declared to originate from the human gut of Western subjects. Diet is listed among the main factors affecting the composition of the human gut along with other factors such as genetics, lifestyle, and health status. On the basis of this, the lifestyle of mothers, including dietary habits, could have an impact on the bacterial strains that colonize the gut of their babies. Starting from fecal samples, plated onto selective media, of 26 babies, a total of 38 Lactobacillus and 45 Bifidobacterium colonies were isolated and subcultured, identified at the specie level with the partial sequencing of the 16S ribosomal RNA gene, and assessed for safety according to international guidelines for probiotics and European guidance. Only 6 Lactobacillus and 5 Bifidobacterium spp. were included for further analysis for the evaluation of survival rate within the gastrointestinal tract and for adhesive properties on the Caco-2 cell line. Some tests for prebiotic metabolism and growth on reconstituted skimmed milk were also performed. Three Lactobacillus strains and 1 Bifidobacterium strain showing interesting adhesive abilities were included in the in vitro immune-stimulatory test with dendritic cells. Among these isolates, the Bifidobacterium breve 2TA showed the most interesting probiotic properties. The results obtained led to the identification of 4 new potential probiotic strains from Chinese babies to be submitted to further investigations about their metabolic and functional features.