HS-GC with A Simple Pretreatment Protocol to Determine Short-chain Fatty Acids in Mouse Feces and the Effect of Polysaccharide from Acanthopanax trifoliatus (L.) Merr on Their Distribution in Diabetic Mice

Increasing numbers of studies suggest that short-chain fatty acids (SCFAs) are closely related to diabetes. However, the complexity of fecal pretreatment makes the detection of SCFAs in feces relatively difficult. In this study, we established a sample pretreatment protocol that involved no tedious steps, requiring only the grinding of appropriate amounts of feces into powder in liquid nitrogen. The SCFA content in feces was then detected using the headspace-gas chromatography (HS-GC) method. The method achieved good linearity ( R 2  ≥ 0.9940), and the limits of quantification (LOQs) and detection (LODs) of all investigated SCFAs ranged from 0.15 to 0.45 mM and 0.05 to 0.15 mM, respectively. The recoveries of the SCFAs ranged from 91.55 to 103.96% in mouse fecal samples. The HS-GC method was then applied to evaluate the effects of a neutral polysaccharide from Acanthopanax trifoliatus (ATP1-1) on the fecal SCFA content in streptozotocin (STZ)-induced diabetic mice. After 6 weeks of treatment with 140 mg/kg/d ATP1-1, the expression levels of acetic acid, propionic acid, butyric acid, isobutyric acid, isovaleric acid and valeric acid were increased by 215.4, 88.8, 95.3, 300.8, 260.7 and 158.0%, respectively, which indicated that the hypoglycemic effect of ATP1-1 may be related to its impact on SCFAs. Our simplified pretreatment of fecal samples is suitable for the analysis and detection of SCFAs in mouse feces by HS-GC.