ACTH	adrenocorticotropin hormone
ALA	α-linolenic acid
AST	aspartate aminotransferase
BBB	blood–brain barrier
BDNF	brain-derived neurotrophic factor
BUN	blood urea nitrogen
CCK	cholecystokinin
CNS	central nervous system
COVID-19	coronavirus disease 2019
CRF	cortisol release factor
CRP	C-reactive protein
DHA	docosahexaenoic acid
DHCA	dihydrocaffeic acid
DSM-5	Diagnostic and Statistical Manual of Mental Disorders, 5th Edition
EC	epicatechin
ECG	epigallocatechin
EGCG	epigallocatechin-3-gallate
ELS	Early Life Stress
EPA	eicosapentaenoic acid
EVOO	extra virgin olive oil
GABA	gamma-aminobutyric acid
GAL	galanin
GDNF	glial-derived neurotrophic factor
GHDx	Global Health Data Exchange
HAM-D	Hamilton Depression Rating Scale
HDL-C	high-density lipoprotein cholesterol
HPA axis	hypothalamus–pituitary–adrenal
IL-1β	interleukin 1β
IL-6	interleukin 6
LAB	lactic acid bacteria
LCD	low-carbohydrate diet
LPS	lipopolysaccharide
MADRS	Montgomery-Åsberg Depression Rating Scale
Mal-gluc	malvidin-3′-O-glucoside
MAO-A	monoamine oxidase
MCH	melanin-concentrating hormone
MDA	malondialdehyde
MDD	Major Depressive Disorder
MDiet	Mediterranean Diet
MGB axis	microbiota–gut–brain axis
MNA	Mini Nutritional Assessment
NCDs	non-communicable diseases
NPS	neuropeptide S
NPY	neuropeptide Y
OXT	oxytocin
PREDIMED trials	Prevención con Dieta Mediterránea trials
SAMe	S-adenosylmethionine
SCFAs	short-chain fatty acids
SCOBY	symbiotic culture of bacteria and yeast
SD	Sprague-Dawley
SMILES trial	Supporting the Modification of lifestyle in Lowered Emotional States trial
SUN project	Seguimiento Universidad de Navarra project
TNF-α	tumor necrosis factor-α
TrkB	tropomyosin receptor kinase B
VDBP	vitamin D-binding protein
VP	vasopressin
WHO	World Health Organization
ω-3 PUFA	omega 3 polyunsaturated fatty acids