Simultaneous Determination of 7 Short-Chain Fatty Acids in Human Saliva by High-Sensitivity Gas Chromatography-Mass Spectrometry

Abstract

Upon absorption in the intestine of the host animal, the main function of short-chain fatty acids (SCFAs), mainly acetate, propionate and n-butyrate, is as metabolic energy. SCFAs, n-butyrate in particular, can also be found in the mouth. An excess of oral SCFAs may cause not only periodontal diseases but also systemic abnormalities in humans. Previously, we reported a method for simultaneous detection by gas chromatography-mass spectrometry (GC-MS) of acetate, propionate and n-butyrate in serum, urine and saliva. In the present study we used a modified version of this method to detect not only acetate, propionate and n-butyrate, but also iso-butyrate, n-valerate, iso-valerate and caproate, because the latter are suggested to be associated with periodontal diseases. Detection ranges of SCFAs were as follows; 6.25-400 µmol/L (acetate), 0.781-100 µmol/L (propionate and n-butyrate), 0.391-50 µmol/L (iso-butyrate), 0.781-50 µmol/L (n-valerate and iso-valerate) and 1.56-50 µmol/L (caproate). Furthermore, we validated the modified detection method with triple freeze-thaw-cycle recovery tests and intra-and inter-day repeatability. Freezing and thawing did not influence the concentrations of SCFAs in saliva. Upon analysis of five clinical saliva samples, it was observed that, except for n-valerate, which was detected only in two samples, all SCFAs were detected in saliva samples. To conclude, we were able to use a modified method to analyze successfully by GC-MS the salivary concentrations of SCFAs. In addition, we simultaneously detected the salivary concentrations of iso-butyrate, iso-valerate, nvalerate and caproate. This improved method was proved to be reliable to measure the concentrations of SCFAs in saliva.

L-amino acid oxidase-1 is involved in the gut-liver axis by regulating 5-aminolevulinic acid production in mice

“…SCFA concentrations in the mice feces were analyzed using a gas chromatography-mass spectrometry apparatus (GCMS-QP2010 Ultra, Shimadzu, Kyoto, Japan) equipped with an autosampler (AOC 5000, Shimadzu), as previously described with minor modifications [ 15 ]. Briefly, 300 mg of individual mouse feces was diluted with 0.6 mL distilled water.…”

Propionic Acid, Induced in Gut by an Inulin Diet, Suppresses Inflammation and Ameliorates Liver Ischemia and Reperfusion Injury in Mice

“…After centrifugation at 2000 × g for 10 minutes at room temperature, serum samples were collected and stored at -80°C until the detection of SCFAs. The SCFA extraction procedure and analysis methods were the same as those described previously by the Kyoto Institute of Nutrition and Pathology (Kyoto, Japan) ( 30 , 31 ).…”

Enzymatic measurement of short-chain fatty acids and application in periodontal disease diagnosis

“…These measurements were performed at the Kyoto Institute of Nutrition & Pathology (Kyoto, Japan). More detailed operating procedures have been reported previously [15].…”

“…We hypothesized that if we were able to establish a method to quantify SCFAs, particularly C3-C6 including C4 (henceforth referred to as [C3-C6]) and use it to determine the severity of periodontal disease, such a technique would contribute to the promotion of medical and dental coordination using the same index, as well as contribute to the treatment and prevention of a variety of systemic diseases. We previously established a method for the determination of trace amounts of SCFAs in saliva using conventional gas chromatography-mass spectrometry (GC-MS) that complies with the US Food and Drug Administration validation guidelines and reported the concentration distribution of SCFAs in saliva [15]. However, the clinical application of GC-MS has proven to be difficult owing to the complexity of its operation.…”