不同提取方法对粪便中短链脂肪酸含量及稳定性的影响

目的 测定粪便中乙酸、丙酸、丁酸和戊酸等短链脂肪酸的含量,研究不同提取方法和不同计算方法对SCFA含量和稳定性的影响。 方法 采用HPLC法测定粪便中SCFA的含量,采用高通量测序方法测定粪便菌群。 结果 在超纯水提取法中,以粪便湿重计算SCFA含量时,第4天测定的丙酸含量与第1天相比具有较大差异( t =-4.30, P =0.05);以OUT计算时,第4天测定的丁酸含量与第2天相比具有显著差异( t =5.63, P =0.03),而以属数目计算时,第4天测定的丙酸含量显著高于第1天( t =7.03, P =0.02)。在硫酸过滤法中,当以OUT计算时,第2天测定的丁酸含量高于第1天( t =-4.67, P =0.04),第4天测得的总SCFA含量低于第2天( t =5.98, P =0.03);而分别以湿重和属数目计算的各SCFA含量间均无显著差异。对超纯水提取法和硫酸过滤法进行比较后发现,两种提取方法间无显著差异。 结论 两种SCFA提取方法间无统计学差异,但采用硫酸过滤法提取、以粪便湿重计算时获得的SCFA含量具有较好的稳定性。

Effect of different extraction methods on content and stability of short chain fatty acid in human feces

Objective To determinate the contents of short-chain fatty acids (SCFAs) in human feces and research the effects of different extraction methods and algorithms on the contents and stabilities of SCFAs. Methods The contents of SCFAs were determined by high-performance liquid chromatography (HPLC),and the sequences of gut flora were determined using 16S rRNA high-throughput sequencing. Results In using the ultra-pure water extract method,propionic acid content had marginal significance at the 4th day compared with the 1st day normalized by feces wet weight ( t =-4.30, P =0.05),butyric acid content had significant difference at the 4th day compared with the 2st day normalized by Operational Taxonomic Unit (OUT) of the gut microbial community ( t =5.63, P =0.03),meanwhile,propionic acid content at the 4th day was higher than that at the 1nd day normalized by genus number ( t =7.03, P =0.02). When using the sulfuric acid filtration extract method,butyric acid content in the 2nd day was higher than the 1st day normalized by OUT ( t =-4.67, P =0.04),and the total content of SCFAs at the 4th day was lower than that on the 2nd day ( t =5.98, P =0.03). There was no significant difference of SCFA content among difference measurement time when normalized by feces wet weight and genus number,respectively. Besides,our analysis showed that there was no difference in the SCFA content between the ultra-pure water extract method and the sulfuric acid filtration extract method. Conclusion There was no statistical difference between the two extraction methods. However,under the sulfuric acid filtration method,the fecal SCFAs normalized by wet weight had a better stability.