G protein - coupled receptor 120 ( GPR 120 )

1The authors thank Trine Poulsen, Annette K. Nielsen, and Kasper B. Poulsen for their skilled technical assistance. The project was fi nancially supported by the Danish Council for Strategic Research (FØSU 2101-07-0111). 2Corresponding author: [email protected] ABSTRACT: Free fatty acids (FFA) are produced in the intestine by microbial fermentation. Recently, a family of G protein-coupled receptors (GPR) acting as FFA transporters has been reported including GPR120, which is expressed by intestinal epithelial cells. The GPR120 has been reported to affect the expression of glucagon-like peptide (GLP)-1 as well as function as a control point for anti-infl ammatory effects. The aim of the present study was to evaluate whether 12 selected intestinal bacteria, representing the 4 major phyla present in the intestine, affect intestinal epithelial cell GPR120 and GLP-1 mRNA abundance. Supernatants of the 12 bacteria were added to differentiated Caco2 intestinal epithelial cells cultured on fi lter inserts in concentrations corresponding to a cell:bacteria ratio of 1:200. After 4 h of incubation, changes in cellular mRNA of GLP-1 and GPR120 by bacterial supernatant were examined using real-time reverse transcriptase polymerase chain reaction. The abundance of GLP-1 mRNA decreased when cells were exposed to 4 of the 12 supernatants (P ≤ 0.05) compared with cells without bacteria added. Supernatants from 8 of the 12 bacteria analyzed increased the mRNA level of GPR120 (P ≤ 0.05) compared with cells without bacteria added. The alteration in cellular GPR120 mRNA was observed with bacteria categorized as either probiotics or bacteria capable of inducing an anti-infl ammatory effect. The benefi cial effect of these bacteria may very well be mediated by regulation of GPR120. The regulation of GPR120 by intestinal microbiota represents a direct signaling pathway for gut bacteria to affect host health and metabolism.