Bifidobacterium longum, a Predominant Bifidobacterium in Early-life Infant Potentially Used as Probiotic

In early life, Bifidobacteria are reported as dominant bacteria in the human digestive tract. Bifidobacterium is potential as a probiotic. The probiotic property of Bifidobacterium is strain-specific. This study aimed to identify the Bifidobacterium (isolated from less than one-month-old healthy infant stool that potentially used as probiotic) based on the 16S rRNA gene and determining their simi-larities among Bifidobacteria. The probiotic-potentially Bifidobacterium was re-characterized by performing a Gram�s staining and catalase test. The DNA extraction process was followed by the 16S rRNA amplification using 27F-1492R primers. Sequence similarity was checked by using the BLAST program in the GenBank. The phylogenetic tree was constructed by using a neighbor-joining (NJ) method within the MEGA version 7.0 package. The 16S rRNA gene was presented at 1,500 bp length. Bifidobacterium strains have a 91.14-94.26 sequence similarity to B. longum subsp. longum strain CCUG30698 which is considered as insufficient for species and genus identifications. However, those isolates could be assigned in a phylogenetic position. This present study suggested the B. longum as the dominant strain of Bifidobacterium in the gut of early-life infants which has potential as a probiotic and is considered as an ideal probiotic for human consumption. This study is useful as basic information for other related research, as well as its application in indus-trial or community service fields. © 2023 Elsevier B.V., All rights reserved.