Hippurate produced by gut microbiota: a marker of the gut microbiota diversity and of metabolic health

Aug 10, 2021
Sébastien Bouley

The proper functioning of the gut microbiota has an impact on the general, physical and psychological health. Understanding how the architecture of the microbiota and the function of the bacteria influence the body has become a major objective of research in recent years. In this context, researchers from Inserm, CNRS and University of Paris, in collaboration with teams from INRAE, Imperial College in London and the University of Copenhagen in Denmark have shown that a metabolite from intestinal bacteria, hippurate, is associated with the diversity of the microbiota. It would play an important role for the cardiovascular and metabolic health, in particular by participating in the regulation of blood sugar. For several years, the intestinal microbiota has played a decisive role in health. Numerous scientific studies have pointed out that there is a link between the diversity of intestinal bacteria and certain health parameters, in particular cardiovascular and metabolic. Scientists were interested in hippurate, a metabolite produced by intestinal bacteria that is found in the urine. The scientists combined two methods, DNA sequencing (analysis of the genetic profile) of bacteria in the gut microbiota and the analysis of small metabolites present in the urine, in 271 people in a Danish cohort (the MetaHIT study). It was shown that high levels of hippurate in the urine are associated with a greater diversity of the intestinal flora and an increase in the richness of the microbiota genes, which are two protective parameters of the cardiometabolic risk. In addition, in obese people with a diet high in saturated fat, and at risk of developing cardiovascular and metabolic problems, high levels of hippurate had beneficial effects on weight and metabolic health. These results were supplemented by a validation study in obese mice fed a fatty diet. In these animal models, administration of hippurate improved blood sugar control and stimulated insulin secretion.

The interest of these results is both diagnostic, since hippurate can be considered as a biomarker of microbiota diversity, but also therapeutic. Indeed, one could, for example, consider modifying the microbiota in order to increase the number of intestinal bacteria which can synthesize the precursors of hippurate. This would then increase the levels of hippurate with protective effects on cardiometabolic risk.