Intestinal dysbiosis in pediatric Crohn's disease patients with IL10RA mutations

Table 1 Clinical characteristics of the study population

	IL10RA	CD	HC	P value1
Number of samples	17	17	26
Demographics
Age (mean ± SD, yr)	1.00 ± 0.68	8.92 ± 4.80	1.61 ± 1.71	< 0.001
Sex (M/F)	10/7	11/6	17/9	0.724
Weight and BMI
Weight (mean ± SD, kg)	7.31 ± 2.58	27.18 ± 13.04	NA	< 0.001
BMI (mean ± SD)	14.53 ± 2.20	15.25 ± 2.44	NA	0.6175
Disease activity
CRP (mean ± SD, mg/L)	40.65 ± 28.13	34.06 ± 31.92	NA	0.4486
wPCDAI (mean ± SD)	52.21 ± 17.65	40.88 ± 20.02	NA	0.1253
SES-CD (mean ± SD)	20.56 ± 7.56	12.94 ± 8.60	NA	0.0158
MINI index (mean ± SD)	19.88 ± 4.96	16.47 ± 2.92	NA	0.0027
Disease duration and anemia
Disease duration (mean ± SD, mo)	9.93 ± 7.75	7.10 ± 9.30	NA	0.0706
Disease location
Ileum only (%)	0 (0)	3 (18)	NA	< 0.001
Colon only (%)	17 (100)	3 (18)	NA
Both (%)	0 (0)	11 (64)	NA
Disease behaviour
Montreal classification B1 (%)	11 (65)	15 (88)	NA	0.106
Montreal classification B2 (%)	5 (29)	2 (12)	NA	0.203
Montreal classification B3 (%)	4 (24)	0 (0)	NA	0.033
Montreal classification P (%)	16 (94)	4 (24)	NA	< 0.001
Serology
IL6 (mean ± SD, pg/mL)	122.47 ± 152.22	37.50 ± 25.08	NA	0.0211
Birth and breast feeding
Cesarian section (%)	11 (65)	8 (47)	NA	0.300
Breast feeding (%)	14 (82)	13 (76)	NA	0.671
IBD medication
Mesalazine (%)	11 (65)	11 (65)	NA	1.000
Steroids (%)	1 (6)	2 (12)	NA	0.542
Thalidomide (%)	4 (24)	0 (0)	NA	0.014
Other medication
Antibiotics (%)	13 (76)	13 (76)	NA	1.000
Proton pump inhibitors (%)	1 (6)	9 (53)	NA	0.001
Marzulene-S (%)	1 (6)	1 (6)	NA	1.000
Self-reported diets
Amino acid formula (%)	2 (12)	0 (0)	NA	0.089
Extensive hydrolyzed formula (%)	3 (18)	1 (6)	NA	0.277
Other diet (%)	12 (71)	10 (59)	NA	0.473

¹P value for the comparison between IL10RA group and CD group. IL10RA: IL10RA group; CD: Crohn's disease group; HC: Healthy control group; NA: Not applicable; BMI: Body mass index; CRP: C-reactive protein; wPCDAI: Weighted pediatric Crohn's disease activity index; SES-CD: Simple endoscopic score for Crohn's disease; MINI: Mucosal-inflammation non-invasive; IL6: Interleukin 6.

Table 2 Variants/mutations in Crohn's disease candidate genes and the alteration of intestinal microbiome

Ref.	Gene	Human/animal	Major findings
[6,19]	IL10	Il10-/- mice	Decrease in diversity and richness
			↑Proteobacteria and Escherichia coli (during onset of inflammation)
			↓Bacteroidetes and Firmicutes
Current study	IL10RA	Human cohort	Decrease in diversity and increase in variability
			↑Firmicutes, Enterococcaceae, Enterococcus, Lactobacillales, Bacilli, and Micrococcales
			↓Bifidobacteriales, Bifidobacteriaceae, Bifidobacterium, Veillonellaceae, Clostridiales, Clostridia, Selenomonadales, and Negativicutes
[4,7,20]	NOD2	Human cohort	↓Roseburia, Faecalibacterium prausnitzii, Bacteroides and Bacteroidia
			↑Eubacteriaceae and Enterobacteriaceae
[21]	NOD2	Nod2-/- mice	Decrease in diversity and richness
			↑Bacteroides, Bacteroidaceae, and B.acidifaciens
			↓Proteobacteria, Helicobacter hepaticus, and Desulfovibro spp
[22]	ATG16L1	Human cohort	↑Fusobacteriaceae
[4]	CARD9	Human cohort	↓Firmicutes
[23]	CARD9	Card9-/- mice	Decreased stability
			↓Adlercreutzia, Actinobacteria, and Lactobacillus reuteri

Table 3 Correlation of dysbiosis index with clinical variables

Variable	Combined, r1 (P value)	IL10RA, r (P value)	CD, r (P value)
wPCDAI	0.52 (0.002)	0.51 (0.040)	0.54 (0.027)
SES-CD	0.48 (0.005)	0.51 (0.044)	0.35 (0.174)
MINI index	0.26 (0.131)	0.32 (0.213)	0.17 (0.510)
CRP, mg/L	0.11 (0.532)	0.16 (0.526)	0.18 (0.493)
IL6, pg/mL	0.17 (0.346)	0.22 (0.417)	0.01 (0.961)
Hb, g/L	-0.54 (0.0009)	-0.56 (0.022)	-0.51 (0.037)
Disease duration (mo)	-0.35 (0.045)	-0.50 (0.043)	-0.40 (0.109)

¹Spearman's rank order correlation coefficient. wPCDAI: Weighted pediatric Crohn's disease activity index; SES-CD: Simple endoscopic score for Crohn's disease; MINI: Mucosal-inflammation non-invasive; CRP: C-reactive protein; IL6: Interleukin 6; Hb: Hemoglobin.