Bioactive host–microbial metabolites in human nutrition with a focus on aromatic amino acid co‐metabolism

Rapid simultaneous determination of gut microbial phenylalanine, tyrosine, and tryptophan metabolites in rat serum, urine, and faeces using LC–MS/MS and its application to a type 2 diabetes mellitus study

“…It has been well demonstrated that the essential and aromatic amino acids phenylalanine (Phe), tyrosine (Tyr), and tryptophan (Trp) are extensively metabolized by gut microbiota into physiologically active multiple aromatic acids (Figure 1; Dodd et al, 2017; Oliphant & Allen‐Vercoe, 2019; Wikoff et al, 2009). Furthermore, the imbalances of Phe, Tyr, and Trp metabolisms in gut microbiota could result in many metabolic diseases, particularly type 2 diabetes mellitus (T2DM) (Martin & Kussmann, 2017; Neis, Dejong, & Rensen, 2015; Palau‐Rodriguez et al, 2015), suggesting that the gut microbial amino acid metabolites are important factors to clarify the development of T2DM and other related metabolic diseases.…”

“…As shown in Figure 1, Phe, Tyr, and Trp are metabolized into several kinds of indolic and phenolic compounds by gut microbiota (Martin & Kussmann, 2017). By providing various enzymes for biochemical metabolic pathways, gut microbiota can take part in Trp metabolic pathways, producing indole derivatives such as indole‐3‐aldehyde (IAld), indole‐3‐acetic acid (IAA), indole‐3‐propionic acid (IPA), and indole‐3‐acrylic acid (IArA), which are able to mitigate inflammatory responses, improve insulin resistance, and reduce the symptoms of T2DM (Agus, Planchais, & Sokol, 2018).…”

“…Furthermore, the imbalances of Phe, Tyr, and Trp metabolisms in gut microbiota could result in many metabolic diseases, particularly type 2 diabetes mellitus (T2DM) (Martin & Kussmann, 2017;Neis, Dejong, & Rensen, 2015;Palau-Rodriguez et al, 2015), suggesting that the gut microbial amino acid metabolites are important factors to clarify the development of T2DM and other related metabolic diseases.…”