Oligosaccharides in breast milk are key

Overview

Assistant Professor Hiroshi Mori, Associate Professor Takuji Yamada, and Adjunct Professor Ken Kurokawa (also a Professor at the National Institute of Genetics), who teach Life Science and Technology, and Master's student Kazuya Yamamoto* (Department of Life Science and Technology), in collaboration with researchers of the Yakult Central Institute and the Teikyo University School of Medicine, et al., identified that "fucosyllactose" (FL), a component of breast milk oligosaccharide, is vital in the formation of infant intestinal flora dominated by bifidobacteria.

They found that the stool of infants with colonization of FL-utilizing bifidobacteria had a greater proportion of bifidobacteria, higher acetate concentrations, a lower proportion of Enterobacteriaceae, and lower pH values compared to those of infants without. They discovered the fact that a type of ABC transporter³ existing in specific bifidobacteria, which transports FL to bacterial cells, plays a central role in the formation of bifidobacteria-dominated intestinal flora. This shows that the utilization of oligosaccharides by bifidobacteria is vital in forming the symbiotic relationship between an infant and bifidobacteria, and is expected to lead to the unraveling of the significance of the bifidobacteria-dominant intestinal flora in infants.

*Position at time of research

Infant microbiota development and molecular mechanisms of FL utilization by bifidobacteria.

Figure. Infant microbiota development and molecular mechanisms of FL utilization by bifidobacteria.

Infant gut microbiota showed 3 distinct clusters, which underwent directional transition to Bifidobacteriaceae-dominant microbiota, and displayed individual variations in the pace of progression. Isolated bifidobacterial strain showed differences in FL utilization. Colonization of FL-utilizing bifidobacteria are associated with altered gut acetate concentrations, pH, and Enterobacteriaceae and Bifidobacteriaceae abundances in the cohort, which have been previously shown to affect infant health. We subsequently identified a substrate binding protein of the multiple-sugar ABC transporter system is a key genetic factor of FL utilization.

1 Intestinal Flora

a wide variety of microorganisms forms a community and inhabits the intestines of various organisms. This intestinal community of microorganisms can be called intestinal flora. In the case of adult human intestines, the community is estimated to be made up of over tens of trillions of cells, of over hundreds of species.

2 Fucosyllactose (FL)

a type of oligosaccharide most present in human breast milk, with the molecular formula C₁₈H₃₂O₁₅.

3 ABC Transporter

a structure composed of multiple proteins grouped together and existing on biological membranes such as cell membranes. Transports specific substrates through the membrane by utilizing ATP.

Reference

Authors:	Takahiro Matsuki¹, Kana Yahagi¹, Hiroshi Mori², Hoshitaka Matsumoto¹, Taeko Hara¹, Saya Tajima¹, Eishin Ogawa³, Hiroko Kodama³, Kazuya Yamamoto², Takuji Yamada², Satoshi Matsumoto¹, & Ken Kurokawa^{2, 4}
Title of original paper:	A key genetic factor for fucosyllactose utilization affects infant gut microbiota development
Journal:	Nature Communications
DOI :	10.1038/ncomms11939