Determination of Short-Chain Fatty Acids in Serum as Biomarkers of Renal Dysfunction

Short-chain fatty acids (SCFAs) produced by the gut microbiota play an important role in maintaining the immune status of the body. Chronic kidney disease is associated with decreased microbial diversity in the gut and impaired production of SCFAs. In chronic kidney disease, the level of SCFAs in circulating blood decreases; therefore, the development of highly sensitive methods is required for the determination of SCFAs in serum. We have developed a technique for the determination of SCFAs in serum and tested it in a comparative study of serum samples from healthy volunteers and patients with diagnosed chronic kidney disease. The determination of SCFAs (acetic, propionic, oily, valerian, caproic, isobutyric and isovalerian) in blood serum was performed by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS). The limits of determination of the investigated SCFAs by GC-MS method are in the range of 0.05–0.09 µg/mL, by GC-MS/MS method – 0.002–0.007 µg/mL. We showed that in blood serum samples of patients with chronic kidney disease the concentrations of all investigated SCFAs are reduced in comparison with the control group and lie below the limits of detection by GC-MS method.