Freeze-drying enables homogeneous and stable sample preparation for determination of fecal short-chain fatty acids
Freeze-drying enables homogeneous and stable sample preparation for determination of fecal short-chain fatty acids
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DOI：
10.1016/j.ab.2019.113508
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发表时间：
2020-01-15
影响因子：
2.9
通讯作者：
Ohno, Kinji
中科院分区：
文献类型：
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作者：
Ueyama, Jun;Oda, Masaya;Ohno, Kinji
背景：粪便短链脂肪酸（SCFAs）的分析方法有了很大的发展。最近，一些研究报道了SCFAs在胃肠道生理中的作用及其与肠道微生物群和疾病的关系。然而，scfa的粪便内变异性和储存稳定性尚未得到广泛研究。本研究的目的是了解粗粪便中SCFAs测量的局限性，并开发一种使用冷冻干燥技术的有用的预检查程序。方法：采用氯甲酸异丁酯衍生化、正己烷液液萃取、气相色谱-质谱法分离分析健康志愿者粗粪和冻干粪便中的短链脂肪酸。结果：在SCFAS中，异丁酸酯的粪内变异性最大（变异系数为37.7%），而冷冻干燥过程降低了该变异性（变异系数为7.9%）。其他scfa也观察到类似的改善。此外，在4摄氏度下储存24小时，观察到SCFA数量显著减少。结论：冷冻干燥程序提供了粪便SCFA稳定性，即使在室温下储存3天。冷冻干燥程序允许可靠的SCFA测量，而无需劳动密集型过程。因此，冻干方法可用于基础研究、临床研究和流行病学研究。
Background: The analysis methods for fecal short-chain fatty acids (SCFAs) have evolved considerably. Recently, the role of SCFAs in gastrointestinal physiology and their association with intestinal microbiota and disease were reported. However, the intra-fecal variability and storage stability of SCFAs have not been extensively investigated. The aim of this study was to understand the limitations of the measurement of SCFAs in crude feces and develop a useful pre-examination procedure using the freeze-drying technique.Methods: SCFAs in crude feces, obtained from healthy volunteers, and freeze-dried feces were determined by derivatization with isobutyl chloroformate, followed by liquid-liquid extraction with hexane, and separation and analysis using gas chromatography-mass spectrometry.Results: Among the SCFAS, the maximum intra-fecal variability was observed for iso-butyrate (coefficient of variation of 37.7%), but the freeze-drying procedure reduced this variability (coefficient of variation of 7.9%). Similar improvements were also observed for other SCFAs. Furthermore, significant decreases in the SCFA amounts were observed with storage at 4 degrees C for 24 h.Conclusions: The freeze-drying procedure affords fecal SCFA stability, even with storage at room temperature for 3 d. The freeze-drying procedure allows reliable SCFA measurements without labour-intensive processes. Therefore, the freeze-drying procedure can be applied in basic, clinical, and epidemiological studies.