The plates prepared on the previous day were heated to 37 °C and then 100 μL of the fecal suspension (sodium phosphate buffer as a control) and 25 μL of the silymarin working solution (DMSO as a control) were added. The final concentration of the tested extract in the solution was thus 50 µg mL -1 . The plates were sealed in vacuum bags with GENbag anaer and incubated at 37 °C on a shaker (100 rpm). At time points 0, 2, 4, 8 and 24 h, one plate was removed from the experiment and 950 μL of each well was aspirated in microtubes containing 50 μL of sodium azide (the final concentration of NaN3 in the samples was 1.5 mg mL -1 ) to stop the fermentation process. The fermentation liquids were stored at -80 °C until final analysis.