1. Characterization of the butyrate-producing community in samples derived from healthy individuals of nine metagenomic studies (I to IX; n = 826).
Characterization of the butyrate-producing community in samples derived from healthy individuals of nine metagenomic studies (I to IX; n = 826). (A) Overview of butyrate-forming pathways, including all major genes involved. (B) Abundances of bacteria exhibiting respective pathways as percentages of total bacteria. (C) Mean number of observed taxa associated with each pathway in these samples. (D) Relative abundances of taxa comprising all pathways. Only taxa that were detected in >70% of all individuals are shown (along with Butyrivibrio crossotus, which showed high abundances in several samples); all taxa shown are known butyrate producers. Bacteria exhibiting the acetyl-CoA pathway are arranged according to their terminal enzymes, butyryl-CoA:acetate CoA transferase (but) and butyrate kinase (buk); bacteria exhibiting but and buk (both) or lacking both enzymes (alternative [alt.]) are also indicated. Members of the Lachnospiraceae are indicated in bold, Ruminococcaceae are indicated in italics, and Bacteroidetes are underlined. Black bars in violin plots (B) represent means. Error bars represent standard deviations. *, taxa detected in >90% of individuals. gct, glutaconate-CoA transferase (α, β subunit); hgCoAd, 2-hydroxyglutaryl-CoA dehydratase (α, β, and γ subunit); gcd, glutaconyl-CoA decarboxylase (α, β subunit); thl, acetyl-CoA acetyltransferase (thiolase); bhbd, β-hydroxybutyryl-CoA dehydrogenase; cro, crotonase; bcd, butyryl-CoA dehydrogenase (including electron transfer protein α, β subunit); kamA, lysine-2,3-aminomutase; kamDE, β-lysine-5,6-aminomutase (α, β subunit); kdd, 3,5-diaminohexanoate dehydrogenase; kce, 3-keto-5-aminohexanoate cleavage enzyme; kal, 3-aminobutyryl-CoA ammonia-lyase; abfH, 4-hydroxybutyrate dehydrogenase; abfD, 4-hydroxybutyryl-CoA dehydratase and vinylacetyl-CoA 3,2-isomerase (same gene); 4hbt, butyryl-CoA:4-hydroxybutyrate CoA transferase; ato, butyryl-CoA:acetoacetate CoA transferase (α, β subunit).
Marius Vital et al. mSystems 2017; doi: /mSystems