Fatty acids can be categorized into several groups according to the length of the chains: short-chain fatty acids (SCFA) with aliphatic tails of 2-6 carbons; medium-chain fatty acids (MCFA) with aliphatic tails of 6–12 carbons; long-chain fatty acids (LCFA) 13 to 21 carbons in aliphatic tails and Very long chain fatty acids (VLCFA) with aliphatic tails longer than 22 carbons. Here are some studys.