The gut microbiome influences host endocrine functions.

Abstract

The gut microbiome is now considered as an organ contributing to the regulation of host metabolism. Since the finding of the existence of a relationship between the gut microbiome and specific diseases, numerous studies have also deciphered molecular mechanisms explaining how gut bacteria dialogue with host cells and eventually shape metabolism. Both metagenomic and metabolomic analyses have contributed to the discovery of bacterial-derived metabolites acting on host cells. In this review, we examine the molecular mechanisms by which bacterial metabolites are acting as paracrine or endocrine factors thereby regulating host metabolism. We highlight the impact of specific short chain fatty acids on the secretion of gut peptides (i.e., GLP-1, PYY) as well as other metabolites produced from different amino acids and regulating inflammation, glucose metabolism or energy homeostasis. We also discuss the role of gut microbes on the regulation of bioactive lipids that belong to the endocannabinoid system as well as specific neurotransmitters (e.g., GABA, serotonin, NO). Finally, we review the role of specific bacterial components (i.e., ClpB, Amuc_1100) also acting as endocrine factors and eventually controlling host metabolism. In conclusion, this review summarizes recent state-of-the art aiming at providing evidence that the gut microbiome influences host endocrine functions via several bacterial-derived metabolites.