Metabolite sample preparation
The samples were first lyophilized using a lyophilizer (Toffon, Shanghai, China). Then, a mix mill (Retsch, Haan, Germany) equipped with zirconia beads was used to ground the sample into powder form at 35 Hz for 1 min. Approximately 100 mg of the powder sample was then mixed with 70% methanol to achieve 0.1 g/mL of aqueous solution. The metabolites were extracted by ultrasonicating the aqueous sample mixture at 40 Hz for 10 min, followed by centrifugation and filtering.