BMI	Body mass index
C3	Complement component 3
CXCR3	C-X-C chemokine receptor type 3
ELISA	Enzyme-linked immunosorbent assay
FODMAP	Fermentable oligosaccharides, disaccharides, monosaccharides, and polyols
GRADE	Grading of Recommendations Assessment, Development and Evaluation
HP	Haptoglobin
HP1	Haptoglobin 1 allele
HP2	Haptoglobin 2 allele
HP1-1	Haptoglobin 1-1 genotype
HP2-1	Haptoglobin 2-1 genotype
HP2-2	Haptoglobin 2-2 genotype
IBD	Inflammatory bowel disease
IBS	Irritable bowel syndrome
IBS-C	Irritable bowel syndrome, constipation-predominant
IBS-D	Irritable bowel syndrome, diarrhoea-predominant
IBS-M	Irritable bowel syndrome, mixed
I-FABP	Intestinal fatty acid-binding protein
IP	Immunoprecipitation
IQR	Interquartile range
mAb	Monoclonal antibody
MyD88	Myeloid differentiation primary response 88
NCGS	Non-coeliac gluten sensitivity
NOS	Newcastle–Ottawa Scale
NR	Not reported
pre-HP2	Pre-haptoglobin-2
PRISMA	Preferred Reporting Items for Systematic Reviews and Meta-Analyses
SD	Standard deviation
ZO-1	Zonula occludens-1