Study on rapid determination of short-chain fatty acids in human feces by GC-FID

Short-chain fatty acids are important energy sources exisiting in colon mucosa, which have functions of coordinating intestinal flora homeostasis, regulating immunity and anti-inflammation. In order to accurately and rapidly ascertain whether the body is healthy and abundance of intestinal flora, a low-cost and high sensitivity detection method for short-chain fatty acids in human feces by gas chromatography was established. The results showed that the extraction rate of acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid and caproic acid was more than 97% in 10 mg fresh samples stored at 4 ℃. The lowest detection limits of short-chain fatty acids by GC-FID were 0.01~0.02 mM, and the lowest limits of quantitation were 0.02~0.08 mM. The standard recoveries were 83.32%~111.89%, with intra-day precision of 0.91%~1.79% and intra-day precision of 1.21%~2.29%. The experimental results of fecal samples from healthy people and patients with functional dyspepsia showed that the method had excellent accuracy, simple operation and low cost. The experimental results provide guidance for large sample crowd experiments.