Figure 1.

Taxonomic rank associated with dominant bacteria butyrate producers present in the human gut microbiota. All bacteria belong to the Firmicutes phylum. It is possible to divide these into two clusters by 16 rRNA analyses, each defined as a “clostridial cluster”. The first cluster is composed of Rumnococcaceae and Clostridiaceae bacteria, and the latter is composed of Lachnospiraceae bacteria. The production of butyrate preserves gut barrier functions, as well as exerts immunomodulatory and anti-inflammatory effects [29].