5-HT	Serotonin
5-HT2A	Serotonin 5-HT2A receptor
5-HT2C	Serotonin 5-HT2C receptor
5-HT3	Serotonin 5-HT3 receptor
ACR	American College of Rheumatology
ANXA1	Annexin A1
AP-1	Activator protein 1
ASIC	Acid-sensing ion channel
AXIN1	Axis inhibition protein 1
BBB	Blood–brain barrier
BDNF	Brain-derived neurotrophic factor
C1QC	Complement C1q C chain
C4A	Complement component 4
CB1	Cannabinoid receptor 1
CB2	Cannabinoid receptor 2
CCL13	Chemokine (C-C motif) ligand 13
CCL2	Chemokine (C-C motif) ligand 2
CCL4	Chemokine (C-C motif) ligand 4
CD163	Cluster of differentiation 163
CNS	Central nervous system
CoQ10	Coenzyme Q10
CRP	C-reactive protein
CSF	Cerebrospinal fluid
CSU	Chronic spontaneous urticaria
CX3CL1	Chemokine (C-X3-C motif) ligand 1
D2	Dopamine D2 receptor
DII	Dietary Inflammatory Index
DNA	Deoxyribonucleic acid
DRG	Dorsal root ganglia
ELISA	Enzyme-linked immunosorbent assay
ERK	Extracellular signal-regulated kinase
EULAR	European Alliance of Associations for Rheumatology
FBD	Functional bowel disorder
FMT	Fecal microbiota transplantation
FODMAP	Fermentable oligo-, di-, and mono-saccharides and polyols
GDNF	Glial-cell-line-derived neurotrophic factor
JNK	c-Jun N-terminal kinase
IBS	Irritable bowel syndrome
IGF-1	Insulin-like growth factor 1
IL-10	Interleukin 10
IL-13	Interleukin 13
IL-17	Interleukin 17
IL-1β	Interleukin 1 beta
IL-21	Interleukin 21
IL-22	Interleukin 22
IL-37	Interleukin 37
IL-4	Interleukin 4
IL-6	Interleukin 6
IL-8	Interleukin 8
IGUBAC-Diet®	Inflammatory gut–brain axis control diet
MMP-3	Matrix metalloproteinase-3
MOR	μ-opioid receptor
NA	Noradrenaline
NF-κB	Nuclear factor kappa-light-chain-enhancer of activated B cells
NMDA	N-methyl-D-aspartate
NPY	Neuropeptide Y
NRI	Selective noradrenaline reuptake inhibitor
NSAID	Non-steroidal anti-inflammatory drug
p38 MAPK	p38 mitogen-activated protein kinase
PGAM1	Phosphoglycerate mutase 1
RAGE	Receptor for advanced glycation end products
RCT	Randomized controlled trial
RLS	Restless leg syndrome
RNA	Ribonucleic acid
RT-qPCR	Reverse transcription-quantitative polymerase chain reaction
S100	S100 protein
S100A8	S100 calcium-binding protein A8
S100A9	S100 calcium-binding protein A9
SERPINA1	Serpin family A member 1
SIRT2	NAD-dependent deacetylase sirtuin 2
SNRI	Serotonin-noradrenaline reuptake inhibitor
SP	Substance P
SS	Symptom Severity
SSRI	Selective serotonin reuptake inhibitor
TCA	Tricyclic antidepressant
TLR4	Toll-like receptor 4
TNF-α	Tumor necrosis factor alpha
TRPV	Transient receptor potential vanilloid
VCAM	Vascular cell adhesion molecule
VGCC	Voltage-gated calcium channel
WPI	Widespread Pain Index