Adrian McCann, PhD: No relevant financial relationship(s) with ineligible companies to disclose.
Objectives: Short chain fatty acids (SCFAs) are a group of organic acids produced by the fermentation of dietary fiber by gut bacteria in the colon. SCFAs have important physiological roles including the regulation of immune function, inflammation and metabolism and are increasingly linked with chronic diseases such as inflammatory bowel disease, type 2 diabetes, obesity and colorectal cancer.
However, there are several challenges with measuring SCFAs in serum or plasma, including their rapid metabolism and interference from other metabolites, and there is a need to develop accurate and reliable methodology for research and diagnostic purposes. Herein, we describe the development and validation of an isotope-labeled gas chromatography-tandem mass spectrometry (GC-MS/MS) method with automated sample workup for the determination of 8 SFCAs in serum/plasma.
Methods: 50μL of serum/plasma was mixed with acetonitrile, benzyl alcohol, pyridine, and methylchloroformate, derivatized and extracted by addition of hexane. The resulting hexane layer was used for GC-MS/MS analysis of formate, acetate, propionate, isobutyrate, butyrate, α-methylbutyrate, isovalerate and valerate.
Results: Chromatographic run time was 8 min. The limit of detection for the lowest concentration SCFAs (α-methylbutyrate, isovalerate, and valerate) were 0.05, 0.02 and 0.05 umol/L, respectively, while all other SCFAs demonstrated sensitivity substantially lower than endogenous concentrations. Recoveries ranged from 82-110% and within- and between-day coefficient of variance were 3.3-9.3% and 2.3-5.9%, respectively.
Conclusions: This low-volume, high-throughput assay is currently in use in our laboratory, and can be used for intervention and epidemiological studies investigating SCFAs and the microbiome in relation to health and disease outcomes.
