Table 1.

Precursors, biosynthetic pathways, and producers of SCFAs.

SCFAs	Precursors	Pathways	Producers
Acetate	Pyruvate	Acetyl-CoA pathway	Most intestinal bacteria, such as Bacteroides spp., Prevotella spp., Ruminococcus spp., Bifidobacterium spp., and Akkermansia muciniphila
		Wood–Ljungdahl pathway	Clostridium spp., Streptococcus spp., and Blautia hydrogenotrophica
Propionate	Phosphoenol-pyruvate	Succinic pathway	Bacteroides spp., Dialister spp., Phascolarctobacterium succinatutens, and Veillonella spp.
		Acrylic pathway	Coprococcus catus and Megasphaera elsdenii
	Deoxyhexose	Propanediol pathway	Ruminococcus obeum, Roseburia inulinivorans, and Salmonella spp.
Butyrate	Acetyl-CoA	Acetate CoA-transferase pathway	Faecalibacterium prausnitzii, Eubacterium hallii, and Roseburia spp.
		Butyrate kinase pathway	Coprococcus catus and Coprococcus comes
	Proteins	Lysine pathway	Odoribacter splanchnicus and Alistipes putredinis