Thanks for your suggestion, we have sorted out the method part again, and now the modification is as follows: “Feces samples and food samples were pretreated in the same way. The digestion process was repeated until the sample becomes sticky.
Then, the feces were freeze‒dried (under vacuum conditions, the vacuum freeze drier temperature is ‒40°C to ‒50°C for 48 h) after measuring the weight with a vacuum freeze dryer.” Point 4.