Maturation of the murine cecal microbiota as revealed by terminal restriction fragment length polymorphism and 16S rRNA gene clone libraries.

The maturation of murine cecal microbiota was determined by terminal restriction fragment polymorphism (T-RFLP) and 16S rRNA gene clone libraries. Cecal microbiota in specific pathogen free (SPF) mice aged four to 10 weeks were collected. The cluster of samples in 4-week-old mice was different from those of other ages based on T-RFLP profiles. The majority of clones obtained in this study belonged to the Clostridium coccoides (C. coccoides) group, the Bacteroides group or the Lactobacillus group. Phylogenetic analysis showed characteristic clusters composed of new operational taxonomic unit (OTU) of the C. coccoides and Bacteroides groups. The existence of a large number of yet unidentified bacteria inhabiting the murine cecum was demonstrated by 16S rRNA gene clone libraries. T-RFLP analysis data were more complex and more sensitive than the patterns generated by computer simulation of 16S rRNA gene clone library analysis data. T-RFLP revealed development with maturation of cecal microbiota including unidentified bacteria of SPF mice.