Abstract:This study analyzed the biological properties of 38 Bifidobacterium longum strains isolated from host with different ages, including growth curve, carbohydrate fermentation test, short-chain fatty acid composition, production of exopolysaccharide and alignment and phylogenetic analysis of priming glycosyltransferase. The results showed that infant originated strains were mostly able to ferment mannose, but adult originated strains were mostly not able to ferment mannose. In addition, we found that the production of cell-surface-bound EPS of infant originated strains were lower than adult originated strains, especially elder originated strains. Finally, the phylogenetic analysis of amino acid sequence of priming glycosyltransferase indicated that infant originated strains were largely clustered together.