Margaric acid (Heptadecanoic acid, C17) is a fatty acid of exogenous (primarily ruminant) origin. Many "odd" length long chain amino acids are derived from the consumption of dairy fats (milk and meat). Heptadecanoic acid constitutes 0.61% of milk fat and 0.83% of ruminant meat fat. The content of heptadecanoic acid in the subcutaneous adipose tissue of humans appears to be a good biological marker of long-term milk fat intake in free-living individuals in populations with high consumption of dairy products. Margaric acid is a metabolite in glutamate and lipid metabolism in vivo. Blood-brain barrier permeable. Orally active. Possibly involved in anti-tumor activity.

Glycodeoxycholic acid (GDCA), a bile acid, is formed in the liver from chenodeoxycholate and glycine. GDCA was one of twenty-five plasma metabolites, which were significantly different among asthma and healthy controls. Besides, GDCA was elevated in patients with acetaminophen-induced acute liver failure (AALF) and was significantly increased in non-surviving AALF patients compared with survivors. Thus GDCA level could serve as a prognostic biomarker for AALF patients.