ADHD	Attention-deficit hyperactivity disorder
ASD	Autism spectrum disorder
BAI	Beck Anxiety Inventory
CFU	Colony-forming unit
CIs	Confidence intervals
DASS-42	Depression Anxiety Stress Scale 42
DHA	Docosahexaenoic acid
EPA	Eicosapentaenoic acid
FOS	Fructooligosaccharides
GABA	Gamma-aminobutyric acid
GBA	Gut–brain axis
GOS	Galactooligosaccharides
miRNA	Micro-RNA
mRNA	Messenger RNA
PGN	Peptidoglycan
PSWQ	Penn State Worry Questionnaire
PUFAs	Omega-3-polyunsaturated fatty acids
RoB-2	Risk of bias tool for randomization trials
SCFAs	Short-chain fatty acids
STAI	State-Trait Anxiety Inventory
VAS	Visual Analogue Scale