Abstract
The ketogenic diet (KD) is a low-carbohydrate, high-fat and adequate-protein diet. As a diet mimicking fasting, it triggers the production of ketone bodies (KBs) and brings the body into a state of ketosis. Recent and accumulating studies on humans and animal models have shown that KD is beneficial to neurodegenerative diseases through modulating central and peripheral metabolism, mitochondrial function, inflammation, oxidative stress, autophagy, and the gut microbiome. Complicated interplay of metabolism, gut microbiome, and other mechanisms can regulate neuroinflammation in neurodegenerative diseases by activating multiple molecular and cellular pathways. In this review, we detail the physiological basis of the KD, its functions in regulating neuroinflammation, and its protective role in normal brain aging and neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), and Huntington's disease (HD). We aimed to elucidate the underlying neuroinflammatory mechanisms of KD therapies in neurodegenerative diseases and provide novel insights into their application for neurodegenerative disease prevention and treatment.