Quantitative analysis of short chain fatty acids in biological samples by liquid chromatography-mass spectrometry

Abstract

Short chain fatty acids (SCFAs) are one of main metabolites produced by gut microbiota activity. The major interest for SCFA research was to find out its relation in energy metabolism, gastrointestinal tract functions and effect of gut-brain axis. In this study, we analyzed relation between cognitive ability and SCFA concentration in colon along with SCFA content change caused by bacterial strain. The idea is originated from gut-brain axis, the bidirectional responses between nervous system and intestinal function. Here, the quantitative analysis of SCFAs were done by liquid chromatography tandem mass spectrometry (LC-MS/MS) in two instruments via 3-nitrophenylhydrazine (3-NPH) chemical derivatization for nine C2-C6 SCFAs. In our quantification, the SCFA content change by SR79 (Agathobaculum butyriciproducens) bacterial strain in mice feces and cell culture medium is tested. The cell culture experiment regarding SR79 strain showed increased content of 6 out of 9 SCFAs in supernatant and 3 out of 9 SCFAs in pellet samples. The overall concentration showed most of SCFA present in supernatant rather than pellet samples. SR79 strain injected mice fecal samples showed increased content of 4 out of 9 SCFAs. In comparison with other mice without SR79 injection, the SR79 strain injected mice showed increased cognitive ability and showed reduced production of SCFAs in colon. Hence, it is assumed that not only production of SCFA affects the colon health but adjusting the optimal concentration of SCFAs would be recommended.