Imidazole propionate (ImP) is a histidine metabolite formed by microbiota. Blood ImP levels are positively associated with a dysbiotic microbiome (Bacteroides 2 enterotype and reduced gene richness), induced by an unhealthy diet, and elevated circulating ImP is linked to gut inflammation and cardiovascular disease. ImP is increased in pre- and type 2 diabetes and is associated with markers of impaired glucose status, independent of diabetes status (2). Mechanistic studies indicate that ImP impairs insulin signalling at the level of Insulin Receptor Substrate (IRS) through activation of the P38gamma/p62/mTORC1 pathway (3).
Assessment of diabetes risk, and profiling of microbiota-derived metabolites.
Matrix: Serum, EDTA plasma and urine
Volume: Minimum volume is 60 µL, but 200 µL is optimal and allows reanalysis.
Preparation and stability: Probably stable.
Reported values: 3-500 nmol/L
Intraclass correlation coefficient (ICC): na.
1. Midttun, O., Hustad, S., and Ueland, P.M. (2009). Quantitative profiling of biomarkers related to B-vitamin status, tryptophan metabolism and inflammation in human plasma by liquid chromatography/tandem mass spectrometry. Rapid Commun Mass Sp 23, 1371-79.
2. Molinaro, A., Bel Lassen, P., Henricsson, M., Wu, H., Adriouch, S., Belda, E., Chakaroun, R., Nielsen, T., Bergh, P. O., Rouault, C., André, S., Marquet, F., Andreelli, F., Salem, J. E., Assmann, K., Bastard, J. P., Forslund, S., Le Chatelier, E., Falony, G., . . . Bäckhed, F. (2020). Imidazole propionate is increased in diabetes and associated with dietary patterns and altered microbial ecology. Nat Commun, 11, 5881.
3. Koh, A., Molinaro, A., Ståhlman, M., Khan, M. T., Schmidt, C., Mannerås-Holm, L., Wu, H., Carreras, A., Jeong, H., Olofsson, L. E., Bergh, P. O., Gerdes, V., Hartstra, A., de Brauw, M., Perkins, R., Nieuwdorp, M., Bergström, G., & Bäckhed, F. (2018). Microbially produced imidazole propionate impairs insulin signaling through mTORC1. Cell, 175, 947-961.