Intestinal Epithelial Tet2 Deficiency Reprograms the Gut Microbiota through Bile Acid Metabolic Alterations

Epigenetic mechanisms are increasingly recognized as critical regulators of host-microbiota interactions. Here, we report that intestinal epithelial-specific deletion of Tet2, a key DNA demethylase, leads to structural abnormalities, impaired barrier function, and remarkable reprogramming of the gut microbial community. Mechanistically, Tet2 deficiency significantly downregulated the expression of the apical sodium-dependent bile acid transporter (ASBT/Slc10a2), resulting in altered bile acid homeostasis with specific accumulation of hyocholic acid (HCA) in the intestinal lumen. This metabolic shift created a favorable niche for selective expansion of bile salt hydrolase (BSH)-expressing Lactobacillus species. Furthermore, we identified an age-dependent regulatory role of HCA in shaping microbial composition, promoting Lactobacillus in young mice while enriching Akkermansia in aged animals. Our findings unveil an epigenetic-metabolic-microbial axis centered on Tet2-mediated regulation of bile acid metabolism, providing new insights into how host epigenetic factors shape the gut microbial ecosystem.