Used as a stable isotope-labeled internal standard in mass spectrometry and metabolic studies to accurately quantify butyrate and its metabolites in biological samples. Enables tracing of metabolic pathways involving short-chain fatty acids, particularly in gut microbiome research, where it helps assess microbial fermentation, energy metabolism, and host-microbe interactions. Also applied in epigenetic studies due to butyrate’s role as a histone deacetylase inhibitor, allowing researchers to monitor changes in gene expression with precise isotopic tracking.