Sodium butyrate

Chr (purity ≥ 99%) was obtained from the National Institute for the Control of Pharmaceutical and Biological Products (Beijing, China). LPS (055:B5), the HMGB1 antagonist sodium butyrate (SB), and the HDAC3 antagonist RGFP966 were obtained from MedChemExpress (New Jersey, United States). Dexamethasone (DEX) was purchased from Shanghai Winherb Medical Technology Co., Ltd. (Shanghai, China). TNF-α, IL-6, IL-1β, and HMGB1 enzyme-linked immunosorbent assay (ELISA) kits were purchased from Multi Sciences Biotech Co. Ltd. (Hangzhou, China). Malondialdehyde (MDA), myeloperoxidase (MPO), and superoxide dismutase (SOD) kits were purchased from the Jiancheng Bioengineering Institute (Nanjing, China). Dual-Luciferase^® reporter assay kits were purchased from Promega (Madison, WI, United States). Antibodies against HMGB1 (#6893), HDAC3 (#3949), TNF-α (#11948), IL-1β (#12703), IL-6 (#12912), inhibitor of nuclear factor kappa B (IκBα) (#4814), acetylated-lysine (#9441), NF-κB p65 (#8242), β-actin (#4970), lamin B (#13435), phospho-p65 (#3031), and phospho-IκBα (#2859) were purchased from Cell Signaling Technology (Danvers, MA, United States). All reagents used for cell culture were obtained from Gibco (Grand Island, NY, United States).

To induce acute DSS colitis, drinking water with 2.5% (wt/vol) DSS (36–50 kDa, MP Biomedicals) was administered to the mice for 10 days (Days 1–10). Mice were gavaged with either LB, EcN or EcN‐Sj16 (1 × 10⁹ bacteria in 200 μL of LB) on Days 0, 4, and 8. The water + LB and DSS + LB groups were gavaged with 200 μL of LB. Sodium butyrate (50 μmol) (MedChemExpress), retinoic acid (400 μg) (MedChemExpress), citral (400 μg) (MedChemExpress), or vehicle were treated to mice from Days 1–9 via intraperitoneal injection. Fresh fecal samples were collected daily in the morning and assayed for EcN and EcN‐Sj16 strains by plating on agar plates containing ampicillin.