L-isoleucine is the L-enantiomer of isoleucine. It has a role as a mouse metabolite, a Saccharomyces cerevisiae metabolite, a plant metabolite, an Escherichia coli metabolite, a human metabolite and an algal metabolite. It is a L-alpha-amino acid, an aspartate family amino acid, an isoleucine and a proteinogenic amino acid. It is a conjugate base of a L-isoleucinium. It is a conjugate acid of a L-isoleucinate. It is an enantiomer of a D-isoleucine. It is a tautomer of a L-isoleucine zwitterion. L-Isoleucine often impacts muscle repair function, cirrhosis, obesity, cardiovascular disease, glucose and lipid metabolism, blood glucose levels and other conditions. L-Isoleucine administration can regulate the inflammatory response to protect against pathogens in vivo and in vitro, making it for research in dextran sulfate sodium (DSS) (HY-116282) -induced colitis.