Farnesoid X Receptor Agonist GW4064 Protects Lipo-2 Polysaccharide-Induced Intestinal Epithelial Barrier 3 Function and Colorectal Tumorigenesis Signaling 4 Through the αKloth/βKlotho/Fgfs Pathways

The farnesoid X receptor (FXR)/βKlotho/fibroblast growth factors (FGFs) pathway is crucial for maintaining the intestinal barrier and preventing colorectal cancer (CRC). We used an FXR ago-nist, GW4064, and FXR knockout (KO) mice to investigate the role of FXR/Klothos/FGFs pathways in lipopolysaccharide (LPS)-induced intestinal barrier dysfunction and colon carcinogenesis. The results showed that upregulation of FXR in enterocytes effectively ameliorated intestinal tight junction markers (claudin1, Zonula occludens-1), inflammation, and bile acid levels, thereby protecting mice from intestinal barrier dysfunction and colon carcinogenesis. GW4064 treatment increased FXR, αKlotho, βKlotho, FGF19, FGF21, and FGF23 in wild-type mice exposed to LPS, while FXR KO mice had decreased levels. FXR KO mice exhibited elevated colon cancer markers (β-catenin, LGR5, CD44, CD34, Cyclin D1) under LPS, underscoring the pivotal role of FXR in inhibiting the development of colon tumorigenesis. The varying gut microbiota responses in FXR KO mice versus wild-type mice post-LPS exposure emphasize the pivotal role of FXR in pre-serving intestinal microbial health, involving Bacteroides thetaiotaomicron, Bacteroides acidifaciens, and Helicobacter hepaticus. Our study validates the effectiveness of GW4064 in alleviating LPS-induced disruptions to the intestinal barrier and colon carcinogenesis, emphasizing the importance of the FXR/αKlotho/βKlotho/FGFs pathway and the interplay between bile acids and gut microbiota.