Short-chain fatty acids in the normal human feces

Area of Science:

• Gastroenterology
• Microbiome Research
• Analytical Chemistry

Background:

• Short-chain fatty acids (SCFAs) are crucial metabolites produced by gut bacteria.
• Understanding SCFA profiles in human feces is important for microbiome research.
• Previous studies have investigated SCFA levels, but variations and comparisons between specific subject groups require further elucidation.

Purpose of the Study:

• To quantify the concentrations and relative compositions of SCFAs in the feces of healthy individuals.
• To compare SCFA profiles between methane-excreting and non-methane-excreting subjects.
• To assess the reliability and variability of a specific analytical method for fecal SCFA determination.

Main Methods:

• Fecal samples from 20 healthy subjects (10 methane excretors, 10 non-methane excretors) were analyzed.
• A validated analytical procedure involving homogenization, vacuum distillation, and gas chromatography was employed.
• Method validation demonstrated high recoveries (90-109%) and acceptable inter-assay reproducibility (6.0-19.7%).

Main Results:

• SCFAs were identified as the quantitatively dominant anions in healthy human feces.
• No significant differences in SCFA concentrations or relative compositions were observed between methane-excreting and non-methane-excreting groups.
• Individual variations in SCFA concentrations were substantial and deemed biological rather than methodological.

Conclusions:

• The study confirms SCFAs as major fecal anions in healthy individuals.
• Methane excretion status does not appear to influence fecal SCFA profiles in this cohort.
• Observed SCFA variations represent genuine biological differences among individuals.