Is involved in a saturation metabolic pathway of polyunsaturated fatty acids, that detoxifies unsaturated fatty acids and generates hydroxy fatty acids, oxo fatty acids, conjugated fatty acids such as conjugated linoleic acids (CLAs), and partially saturated trans-fatty acids as intermediates. CLA-ER catalyzes the saturation of the carbon-carbon double bond in 10-oxo-(11E)-octadecenoate to produce 10-oxooctadecanoate, during linoleate metabolism. As part of the gut microbiome, this enzyme modifies host fatty acid composition and is expected to improve human health by altering lipid metabolism related to the onset of metabolic syndrome