Short chain fatty acids (SCFAs) are important regulators of host physiology and metabolism and may contribute to obesity and associated metabolic diseases. Interest in SCFAs has increased in part due to the recognized importance of how production of SCFAs by the microbiota may signal to the host. Therefore, reliable, reproducible, and affordable methods for SCFA profiling are required for accurate identification and quantitation. In the current study, four different methods for SCFA (acetic acid, propionic acid, and butyric acid) extraction and quantitation were compared using two independent platforms including gas chromatography coupled with mass spectrometry (GC–MS) and 1H nuclear magnetic resonance (NMR) spectroscopy. Sensitivity, recovery, repeatability, matrix effect, and validation using mouse fecal samples were determined across all methods. The GC–MS propyl esterification method exhibited superior sensitivity for acetic acid and butyric acid measurement (LOD < 0.01 μg mL–1, LOQ < 0.1 μg mL–1) and recovery accuracy (99.4%–108.3% recovery rate for 100 μg mL–1 SCFA mixed standard spike in and 97.8%–101.8% recovery rate for 250 μg mL–1 SCFAs mixed standard spike in). NMR methods by either quantitation relative to an internal standard or quantitation using a calibration curve yielded better repeatability and minimal matrix effects compared to GC–MS methods. All methods generated good calibration curve linearity (R2 > 0.99) and comparable measurement of fecal SCFA concentration. Lastly, these methods were used to quantitate fecal SCFAs obtained from conventionally raised (CONV-R) and germ free (GF) mice. Results from global metabolomic analysis of feces generated by 1H NMR and bomb calorimetry were used to further validate these approaches.
Elsa Fonseca says
Regards,
I am very interested in your work on SCFA by CG-EM and H1 NMR. Currently I am developing my doctoral thesis and I need to quantify the SCFA present in 25 cryopreserved samples of fecal chicken feces subjected to experimental diets with prebiotics.
I would like to know if you have implemented the method and provide the analysis service or if there is any possibility of different collaboration, in this semester I must go to the Material Research Institute at Penn State to carry out some other research trials, so I would love in this Visit to meet you and your research group.