Transporter that facilitates the transmembrane diffusion of D/L-lactic acid. Is involved in the cellular racemization of lactate and lactate metabolism. The transported molecule is indeed lactic acid and not the lactate anion, in agreement with the assumption that, with very few exceptions, MIPs (major intrinsic proteins) only facilitate the transport of uncharged solutes. Also facilitates urea and H(2)O(2) diffusion across membranes, but is not permeable to water, glycerol and dihydroxyacetone. Induced by L-lactate and repressed by D-lactate. Is thus regulated by the L-lactate/D-lactate ratio. Makes part of the lar operon (larABCDE). Cells lacking this gene show a decreased lactate transport ability (PubMed:23799297). Deletion of this gene does not affect lactate racemase activity (PubMed:24710389). Belongs to the MIP/aquaporin (TC 1.A.8) family.