Neonatal oral fluid as a transmission route for bifidobacteria to the infant gut immediately after birth

• Published in: Scientific reports Vol. 9; no. 1; pp. 8692 - 9
• Main Authors: Toda, Kazuya, Hisata, Ken, Satoh, Takumi, Katsumata, Noriko, Odamaki, Toshitaka, Mitsuyama, Eri, Katayama, Takane, Kuhara, Tetsuya, Aisaka, Kohzo, Shimizu, Toshiaki, Xiao, Jin-zhong
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 18-06-2019; Nature Publishing Group
• Subjects: 38/23; 38/77; 45/22; 631/326/2565/107; 631/61/212/748; Babies; Bacteria; Bifidobacteriales Infections - microbiology; Bifidobacteriales Infections - transmission; Bifidobacterium; Bifidobacterium - classification; Bifidobacterium - genetics; Bifidobacterium - isolation & purification; Birth; Breastfeeding & lactation; Cesarean section; Cluster Analysis; Feces - microbiology; Female; Gastrointestinal Microbiome - genetics; Gastrointestinal Tract - microbiology; Homology; Humanities and Social Sciences; Humans; Infant; Infant, Newborn; Intestinal microflora; Male; Microbiota; Mouth - microbiology; multidisciplinary; Neonates; RNA, Ribosomal, 16S - genetics; rRNA 16S; Saliva - microbiology; Science; Science (multidisciplinary); Sequence Analysis, DNA - methods; Species Specificity; Strains (organisms); Vagina
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-019-45198-9

Bifidobacteria are one of the most abundant bacterial groups in the infant gut microbiota and are closely associated with infant health and can potentially affect health in later life. However, the details regarding the source of bifidobacteria have yet to be completely elucidated. This study aimed to assess neonatal oral fluid (OF) as a transmission route for bifidobacteria to the infant gut during delivery. Neonatal OF and infant feces (IF) were collected immediately and one month after birth from 15 healthy vaginally delivered newborns.
Bifidobacterium
strains were isolated from OF and IF samples, and the similarity of strains between the OF-IF pairs was evaluated based on the average nucleotide identity (ANI) value. The 16S rRNA gene sequencing results revealed the presence of Bifidobacteriaceae at >1% relative abundance in all OF samples.
Bifidobacterium
strains were isolated from OF (9/15) and IF (11/15) samples, and those sharing high genomic homology (ANI values >99.5%) between the neonatal OF and IF samples were present in one-third of the OF-IF pairs. The results of this study indicate that viable bifidobacteria are present in neonatal OF and that OF at birth is a possible transmission route of bifidobacteria to the infant gut.