Sensitive and quantitative determination of short-chain fatty acids in human serum using liquid chromatography mass spectrometry

Armaghan Shafaei,David Broadhurst,Veronica Vamathevan,Mary C Boyce,Nathan G Lawler,Jessica Pandohee

doi:10.1007/s00216-021-03589-w

Armaghan Shafaei, David Broadhurst + Show 4 more

Open Access

https://doi.org/10.1007/s00216-021-03589-w

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Journal: Analusis	Publication Date: Aug 11, 2021
Citations: 24	License type: open-access

Affiliation: Edith Cowan University, Murdoch University, Curtin University

Abstract

Short-chain fatty acids (SCFAs) are increasingly being monitored to elucidate the link between gut health and disease. These metabolites are routinely measured in faeces, but their determination in serum is more challenging due to their low concentrations. A method for the determination of eight SCFAs in serum is described here. High-resolution mass spectrometry and gas chromatography were used to identify the presence of isomeric interferences, which were then overcome through a combination of chromatographic separation and judicious choice of MS fragment ion. The SCFAs were derivatised to form 3-nitrophenylhydrazones before being separated on a reversed-phase column and then detected using liquid chromatography tandem mass spectrometry (LC-QQQ-MS). The LODs and LOQs of SCFAs using this method were in the range 1 to 7 ng mL−1 and 3 to 19 ng mL−1, respectively. The recovery of the SCFAs in serum ranged from 94 to 114% over the three concentration ranges tested.

Highlights

Short-chain fatty acids (SCFAs) are the end products of fermentation of dietary fibre by anaerobic intestinal microbiota
We report the use of gas chromatography (GC) and LC both coupled to a high-resolution mass spectrometry as orthogonal methods that use fundamentally different principles to inform the development of an LC-MS/MS method
For parallel reaction monitoring (PRM) analysis, at least two product ions were monitored and the collision energy which gave the optimal signal for these product ions was experimentally determined and adopted (Table S1)

Summary

Introduction

Short-chain fatty acids (SCFAs) are the end products of fermentation of dietary fibre by anaerobic intestinal microbiota. As humans lack the enzymes to degrade the bulk of dietary fibres, nondigestible carbohydrates pass the upper gastrointestinal tract unaffected and are fermented in the caecum and the large intestine by the anaerobic caecal and colonic microbiota. The SCFAs produced in the caecum/large intestine are absorbed in the colon and either utilised in colonocytes or transported via the portal vein to reach the blood circulation and other organs. Transported SCFAs act as substrates or signal molecules that provide a link between the diet, the microbiota, and the host, and mediate health benefits locally in the gut and at the systemic level [2]. The amount and type of fibre consumed have dramatic effects on the composition of the intestinal microbiota and on the type and amount of SCFAs produced

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