As in humans, the
two most abundant divisions are the Firmicutes (60-80% of sequences) and the Bacteroidetes (20-40%).
Greater than 75% of the Firmicutes are in Clostridium cluster XIVa, a common clade in humans that
includes butyrate producers and Eubacterium eligens. The majority (>88%) of the Bacteroidetes belong to
Bacteroidetes 4b, which lacks a cultured representative. Proteobacteria, Actinobacteria and Cyanobacteria,
present at low levels in the human colonic microbiota, and TM7, previously identified in the
human mouth (gingival) microbiota, each comprise ≤1% of the mouse cecal bacterial community.