Dextran sulphate sodium dss

Dextran sulphate sodium (DSS, MW: 36,000–50,000 Da) was obtained from Yeasen Biotechnology (Shanghai) Co., Ltd. Male C57BL/6 J mice (4 weeks old) were purchased from Shanghai Laboratory Animal Research Center (Shanghai, China). Ethical approval for all animal experimental procedures was provided by the Animal Ethics Committee of Shanghai Laboratory Animal Research Center (Ethics No. 2021082003). Mice were kept in a room with a controlled light schedule (12-h light–dark cycle) and temperature (25 ± 2 °C) with free access to food and water throughout the study. After a 7-day adaptive feeding period prior to study initiation, the mice were randomly divided into three groups (n = 10/group): the control (CTL) group, UC group and BLa80 group. Mice in the CTL group were given tap water; while those in the UC and BLa80 groups were given tap water with DSS (2.5%). Mice in the BLa80 intervention group were administered 10⁹ CFU of BLa80 daily intragastrically by gavage from the next day of DSS administration, while mice in the CTL and UC groups were administered an equal volume of normal saline by gavage. The duration of the modelling and intervention process was 8 days, after which mice in all of the three groups were given untreated drinking water for the rest 4 days.

Dextran sulphate sodium (DSS) (Lot number D7002900) was obtained from Yeasen Biotechnology (shanghai) Co., Ltd (Shanghai, China). Andrographolide (Lot number 110797-201609) and dehydroandrographolide (Lot number 110854-201710) were purchased from National Institutes for Food and Drug Control (Beijing, China). 1-methoxicabony-β-carboline and 4-methoxy-5-hydroxy-canthin-6-one were purified and identified using Infrared Spectroscopy (IR), UV–visible spectroscopy (UV), mass spectrometry (MS), and Nuclear Magnetic Resonance Spectroscopy (NMR) as described in our previous studies, and the purity of them was more than 98% (Yang et al., 2016 (link); Liu et al., 2020 (link); Zhang et al., 2021 (link)). Chloramphenicol (Lot number Y27M6C2), internal standard (IS), was purchased from Shanghai Yuanye Bio-Technology Co., Ltd (Shanghai, China). MS-grade methanol, acetonitrile, and formic acid were obtained from Merck Co., Ltd (Darmstadt, Germany). Deionized water was purified using the Milli-Q system (Millipore, Milford, MA, United States) and used for the entire study. Furthermore, all other reagents were analytical grade from Guangzhou Chemical Reagent Co., Ltd (Guangzhou, China).