SCFA Analysis of Culture Medium

The SCFA analysis was conducted according to a previous study report [10 (link)]. Samples (2 mL) were collected from the culture medium using a sterile syringe at 12 h intervals and stored at −80 °C until the SCFA analysis. Briefly, the samples were centrifuged (5000× g) at room temperature for 15 min, and the supernatant was used for analysis. Gas chromatography (Agilent Technologies, Santa Clara, CA, USA) was equipped with a GC column (DBFFAP 123-3253, 50 m × 0.32 mm × 0.50 μM), flame ionization detector, and an autosampler. The injector and detector port temperatures were 200 and 240 °C, respectively. The carrier gas was N₂ at a flow rate of 1.4 mL/min. The SCFA concentration was expressed in mM.