초록
<P><B>Abstract</B></P> <P>Although most members of the genus <I>Bifidobacterium</I> are unable to utilize xylan as a carbon source, the growth of these species can be induced by this polysaccharide in the gut environment. This indicates a requirement for an association between <I>Bifidobacterium</I> species and some other members of gut microbiota. In this study, the role of cross-feeding between <I>Bifidobacterium</I> and <I>Bacteroides</I> species in the bifidogenic effect of xylan was investigated using <I>in-vitro</I> pure and co-culture fermentations. The pure culture studies showed that among the <I>Bifidobacterium</I> species tested, only <I>Bifidobacterium animalis</I> subsp. <I>lactis</I> was able to utilize xylooligosaccharides. The co-culture of this strain with <I>Bacteroides</I> species enabled it to grow in the presence of xylan. These results suggest that the ability of <I>Bacteroides</I> species to hydrolyze xylan could allow the proliferation of specific <I>Bifidobacterium</I> species in the gut through substrate cross-feeding.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Xylan is a widely available carbohydrate with prebiotic potential. </LI> <LI> Among five <I>Bifidobacterium</I> species, none could grow on xylan in pure cultures. </LI> <LI> Only <I>B. animalis</I> subsp. <I>lactis</I> utilized XOS in pure cultures. </LI> <LI> <I>B. animalis</I> subsp. <I>lactis</I> could grow on xylan in a co-culture with <I>Bacteroides</I> species. </LI> <LI> Results indicate a cross-feeding between <I>Bacteroides</I> and <I>Bifidobacterium</I>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>