Figure 1.

Ketone bodies have neuroprotective effects in the brain. Ketone bodies containing acetoacetate, β-hydroxybutyrate, and acetone generated from a ketogenic diet cross the blood–brain barrier. Firstly, ketone bodies improve the energy metabolism and enhance adenosine triphosphate (ATP) production. Secondly, they normalize mitochondrial function by stimulating mitochondrial biogenesis and reducing oxidative stress, which reduces neuronal death. Thirdly, ketone bodies regulate neurotransmitters and increase γ-aminobutyric acid (GABA) levels. Fourthly, they also inhibit the activation of the mammalian target of rapamycin (mTOR) signaling pathway and decrease seizures. Lastly, ketone bodies modulate the gut microbiota.