A fast and accurate way to determine short chain fatty acids in mouse feces based on GC-MS.

Short-chain fatty acids (SCFAs) in the gut are mainly produced by the anaerobic microbial fermentation of unabsorbed dietary carbohydrates in the large bowel. Quantitative determinations of SCFAs in feces and colonic contents are necessary when studying the impact of fiber-rich food (such as fruits and vegetables) on health. We made the following crucial improvements to the method currently widely used: optimized the lyophilization period from 12 h to 3.5 h; disposed of the procedure for precise weight control; lowered the extraction temperature from 25 °C to 4 °C; shortened the extraction time from 45 min to 15 min; and significantly improved the extraction efficiency of acetic acid, propionic acid and butyric acid by 12.91%, 19.95% and 13.08%, respectively. Furthermore, to evaluate the applicability of this novel approach, we applied our method to determine the SCFAs in the feces and colonic contents of mice fed on different diets, and observed distinct results.