Hyperlactatemia is intimately correlated with severity and poor prognosis of patients with sepsis. However, little experimental evidence on this process is known. We report here that lactate dehydrogenase B (LDHB), the glycolytic enzyme that catalyzes conversion of lactate to pyruvate, is transcriptionally downregulated in blood samples of hyperlactatemic patients, while mice receiving lactate injection have reduced LDHB activity in liver and kidney. LDHB knockout (Ldhb