DOP35 High-fat diet reduces gut microbiota-derived metabolite indole-acetic acid and aggravates colitis

Abstract Background It is widely accepted that high-fat diet (HFD) has been considered as one of the risk factors inflammatory bowel disease(IBD), while mechanism little known. We aimed to examined whether dietary high fat promotes colonic inflammation through modulating gut microbial tryptophan metabolites. Methods The C57BL/6 female mice were fed with chow (12kcal% fat) or HFD (60kcal% for 2 weeks. Fresh fecal samples collected before administration 2% DSS. LC-MS/MS analysis was performed detect Next, 8-week-old administrated 3-indoleacetic acid (IAA) 7 days prior 2.5% DSS treatment. severity colitis assessed and sections collected. RNA sequencing analyze differential genes in intestinal tissue IAA not. Real-time PCR Western blotting transcription protein expression mucin sulfation-related genes. High iron diamine-alcian blue (HID-AB) staining colon tissues LS174T cells used abundance sulfated mucin. Additionally, Chromatin immunoprecipitation (ChIP) confirm binding aryl hydrocarbon receptor(AHR) 3’-phosphoadenosine 5’-phosphosulfate (PAPS) synthase (PAPSS2). Results Short-term increased susceptibility mice. Mice have impaired metabolism remarkable lower level IAA. supplementation resulted ameliorative symptoms. Mechanistically, transcriptome detected enriched cytosolic sulfonation pathway significantly PAPSS2 tissue, a rate-limiting enzyme on sulfation pathway. vivo vitro experiments verified its downstream promoted golgi apparatus AHR. ChIP ChIP-PCR can enhance AHR promoter region , which further PAPS transporter (PAPST2 Slc35b3) ultimately sulfation. Conclusion altered metabolites disrupt protective effect barrier. could relief AHR-PAPSS2-PAPST2-mucin axis, may present potential approach precise prevention treatment IBD.