Acute effects of ketone monoester ingestion on monocyte phenotype and cytokine secretion in healthy humans

Thirteen healthy adults (age 28 +/- 7 years) consumed a ketone monoester at 0.750 g/kg of body mass, with blood drawn before and 2 hours after ingestion. Blood beta-hydroxybutyrate (BHB) peaked at 5.0 +/- 0.8 mmol/L at 2 hours, and total white blood cells rose, mainly because of higher neutrophils. TNF-alpha secretion from LPS-stimulated whole blood was unchanged after ingestion (P = 0.616). In ex vivo experiments, BHB cotreatment decreased TNF-alpha secretion dose-dependently in whole blood and monocyte cultures (P ≤ 0.0012) and reduced monocyte CD80 expression, and lowering pH alone also reduced TNF-alpha, though to a lesser extent.