Intestinal Crosstalk between Bile Acids and Microbiota and Its Impact on Host Metabolism.

The gut microbiota is considered a metabolic "organ" that not only facilitates harvesting of nutrients and energy from the ingested food but also produces numerous metabolites that signal through their cognate receptors to regulate host metabolism. One such class of metabolites, bile acids, is produced in the liver from cholesterol and metabolized in the intestine by the gut microbiota. These bioconversions modulate the signaling properties of bile acids via the nuclear farnesoid X receptor and the G protein-coupled membrane receptor 5, which regulate numerous metabolic pathways in the host. Conversely, bile acids can modulate gut microbial composition both directly and indirectly through activation of innate immune genes in the small intestine. Thus, host metabolism can be affected through microbial modifications of bile acids, which lead to altered signaling via bile acid receptors, but also by altered microbiota composition.

Wahlström A ，Sayin SI ，Marschall HU ，Bäckhed F ... -  《-》

The Role of the Gut Microbiota in Bile Acid Metabolism.

Ramírez-Pérez O ，Cruz-Ramón V ，Chinchilla-López P ，Méndez-Sánchez N ... -  《Annals of Hepatology》

The Role of the Gut Microbiota in Bile Acid Metabolism.

The gut microbiota has been considered a cornerstone of maintaining the health status of its human host because it not only facilitates harvesting of nutrients and energy from ingested food, but also produces numerous metabolites that can regulate host metabolism. One such class of metabolites, the bile acids, are synthesized from cholesterol in the liver and further metabolized by the gut microbiota into secondary bile acids. These bioconversions modulate the signaling properties of bile acids through the nuclear farnesoid X receptor and the G protein-coupled membrane receptor 5, which regulate diverse metabolic pathways in the host. In addition, bile acids can regulate gut microbial composition both directly and indirectly by activation of innate immune response genes in the small intestine. Therefore, host metabolism can be affected by both microbial modifications of bile acids, which leads to altered signaling via bile acid receptors, and by alterations in the composition of the microbiota. In this review, we mainly describe the interactions between bile acids and intestinal microbiota and their roles in regulating host metabolism, but we also examine the impact of bile acid composition in the gut on the intestinal microbiome and on host physiology.

Ramírez-Pérez O ，Cruz-Ramón V ，Chinchilla-López P ，Méndez-Sánchez N ... -  《Annals of Hepatology》

Bile Acid-Activated Receptors, Intestinal Microbiota, and the Treatment of Metabolic Disorders.

The composition of the bile acid pool is a function of the microbial metabolism of bile acids in the intestine. Perturbations of the microbiota shape the bile acid pool and modulate the activity of bile acid-activated receptors (BARs) even beyond the gastrointestinal tract, triggering various metabolic axes and altering host metabolism. Bile acids, in turn, can also regulate the composition of the gut microbiome at the highest taxonomic levels. Primary bile acids from the host are preferential ligands for the farnesoid X receptor (FXR), while secondary bile acids from the microbiota are ligands for G-protein-coupled bile acid receptor 1 (GPBAR1). In this review, we examine the role of bile acid signaling in the regulation of intestinal microbiota and how changes in bile acid composition affect human metabolism. Bile acids may offer novel therapeutic modalities in inflammation, obesity, and diabetes.

Fiorucci S ，Distrutti E 《-》

Bile Acids Activated Receptors Regulate Innate Immunity.

Fiorucci S ，Biagioli M ，Zampella A ，Distrutti E ... -  《Frontiers in Immunology》