Time-Restricted Feeding Enhances Cerebromicrovascular Bioenergetic Health via Increased Ketone Body Production

Ketone bodies, traditionally associated with ketoacidosis as a toxic metabolite have been studied in recent years as a beneficial alternative fuel source. In states of fasting, when glucose levels are low, the liver undergoes ketogenesis to produce ketone bodies; however, this function becomes impaired with aging. Additionally, modern lifestyle patterns, characterized by reduced fasting windows and prolonged periods of continuous feeding, further diminish the natural production of ketone bodies. This study investigated the effects of time-restricted feeding (TRF) to promote ketogenesis in aged mice and an elderly population of adults, exploring its potential effects on endothelial mitochondrial function. To test this hypothesis, we collected serum samples from 24-month-old mice that underwent 6 months of TRF and compared their ketone profiles to both young and age-matched controls on an unrestricted (ad-lib) diet, as well as serum samples from elderly individuals before and after 6 months of TRF. We then evaluated the effects of exogenous ketone bodies on primary human brain microvascular endothelial cell mitochondrial health in vitro. Elisa analysis revealed that TRF in both mice and humans increased levels of circulating β-Hydroxybutyrate (BHB) and AcetoAcetate (AcAc) demonstrating liver ketogenesis is improved following treatment with TRF. Treatment of ketone bodies in vitro enhanced mitochondrial bioenergetics, increased mitochondrial membrane potential, decreased mitochondrial ROS production, increased Nitric Oxide production, and enhanced cellular proliferation. These findings hold significant implications, as aging-induced mitochondrial dysfunction is well-documented, and ketone bodies show promising evidence to enhance mitochondrial health markers in vitro. This study also highlights the role of lifestyle and diet interventions as a therapeutic for vascular health. Future directions involve investigating the effects of ketone bodies on brain endothelial cell mitochondrial biogenesis, mitophagy, and the transcriptome to identify activated genes and pathways in response to ketone body stimulation. CRISPR/Cas9 will be employed to validate these findings. Stephenson Cancer Center, National Institute on Aging R03 AG070479, American Heart Association, HEVO/AFAR This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.