Increase in terminal restriction fragments of Bacteroidetes-derived 16S rRNA genes after administration of short-chain fructooligosaccharides.

It is well known that short chain fructooligosaccharides (scFOS) modify intestinal microbiota in animals as well as in humans. Since most murine intestinal bacteria are still uncultured, it is difficult for a culturing method to detect changes in intestinal microbiota after scFOS administration in a mouse model. In this study, we sought markers of positive change in murine intestinal microbiota after scFOS administration using terminal restriction fragment length polymorphism (T-RFLP) analysis, which is a culture-independent method. The T-RFLP profiles showed that six terminal restriction fragments (T-RFs) were significantly increased after scFOS administration. Phylogenetic analysis of the 16S rRNA partial gene sequences of murine fecal bacteria suggested that four of six T-RFs that increased after scFOS administration were derived from the 16S rRNA genes of the class Bacteroidetes. Preliminary quantification of Bacteroidetes by real-time PCR suggests that the 16S rRNA genes derived from Bacteroidetes were increased by scFOS administration. Therefore, the T-RFs derived from Bacteroidetes are good markers of change of murine intestinal microbiota after scFOS administration.