The Firmicutes are a phylum of bacteria, most of which have the Gram-positive type of cell walls.
Classes
The group is typically divided into the Clostridia, which are anaerobic, the Bacilli, which are aerobic, and the Mollicutes, a class of bacteria which do not have cell walls.
On phylogenetic trees, the first two groups show up as paraphyletic or polyphyletic, as do their main genera, Clostridium and Bacillus.[1]
Health
Firmicutes make up the largest portion of the mouse and human gut microbiome.[2] The division Firmicutes as part of the gut flora has been shown to be involved in energy resorption and obesity.[3][4][5]
References