AD Alzheimer's disease ADL Activities of daily living ASD Autism spectrum disorder BAIBA β-Aminoisobutyric acid BDNF Brain-derived neurotrophic factor BHB β-Hydroxybutyrate CBF Cerebral blood flow EEG Electroencephalogram FGF21 Fibroblast growth factor 21 HPA Hypothalamic-pituitary-adrenal m6A N6-methyladenosine MCI Mild cognitive impairment NF-κB Nuclear factor kappa-B PD Parkinson's disease PFC Prefrontal cortex PGC-1α Peroxisome proliferator-activated receptor gamma coactivator 1-alpha SAM...