Propionate is a type of fatty acid that occurs naturally in the body and in some foods. It is produced during the fermentation of dietary fibers in the gut and is known for its role in energy metabolism. Propionate can also be found in certain dairy products and is used as a food preservative to inhibit mold growth. In addition to its natural occurrence, propionate is often used in the livestock industry as a feed additive to promote growth and improve feed efficiency. It is also studied for its potential health benefits, including its effects on gut health and appetite regulation.