Elevated pro-inflammatory and lipotoxic mucosal lipids characterise irritable bowel syndrome

Table 1 Sociodemographic and clinical characteristics of IBS patients (n = 15) (mean ± SD)

Age (yr)	42 ± 16
Sex (n): F/M	11/4
BMI (kg/m2)	23.3 ± 5.0
Predominant bowel habit1: (n)
Diarrhoea	2
Constipation	3
Alternating	10

¹According to the Rome II criteria; BMI: Body mass index.

Table 2 The 15 lipids with the largest and most significant differences between patients and controls

Lipid name	Fold (IBS/healthy control)	P value1	FDR Q value
Cer (d18:1/24:1)	1.3	0.001	0.022
Cer (d18:1/24:2)	1.4	0.00004	0.0018
DG (36:2)	1.9	0.000001	0.0003
GlycoSL (m/z = 1199.805)	1.9	0.001	0.018
GlycoSL (m/z = 1195.851)	2.0	0.0003	0.0069
lysoPC (16:0)	2.1	0.00006	0.0020
lysoPC (18:0)	1.9	0.0002	0.0049
lysoPC (18:1)	2.8	0.00002	0.0013
lysoPE (18:1e)	2.4	0.00002	0.0013
7TG (46:5)	1.4	0.04	0.19
TG (48:5)	1.6	0.03	0.17
TG (48:6)	1.7	0.03	0.18
TG (49:3)	2.1	0.009	0.089
TG (51:4)	1.6	0.04	0.19
TG (51:5)	1.8	0.02	0.12

¹Wilcoxon rank sum test. Cer: Ceramide; DG: Diacylglycerol; GlycoSL: Glycosphingolipid; lysoPC: Lysophosphatidylcholine; lysoPE: Lysophosphatidylethanolamine; TG: Triacylglycerol.

Table 3 Major water soluble metabolites contributing to differentiation between patients and controls¹

Metabolite	Fold (IBS/healthy control)	P value2	FDR Q value
2(3H)-furanone	13.7	0.03	0.25
Ribitol	3.6	NS	0.25
Heptan	2.9	0.02	0.25
L-Mannose	2.8	NS	0.25
Creatinine	1.7	0.04	0.25
Dodecane	1.5	NS	0.29
Decanoic acid	1.3	NS	0.52
Dodecanoic acid	-1.5	NS	0.25
n-Butylamine	-1.5	0.01	0.25
D-ribose	-1.5	NS	0.25
Glucopyranose	-1.6	NS	0.29
Azelaic acid	-1.8	0.02	0.25
Adipic acid	-2.7	0.0008	0.05

¹Separation is based on a variable importance projection (VIP) analysis with a cut-off value of 2;

²Wilcoxon rank sum test. NS: Not significant.