Correlation between the neuroendocrine axis, microbial species, inflammatory response, and gastrointestinal symptoms in irritable bowel syndrome

Table 1 Comparison of clinical data between two study groups

		Patient group	Healthy group	t/χ2	P value
Number of cases	-	80	80	-	-
Gender	Male	33	35	0.102	0.749
	Female	47	45
Age (years)	-	22-55	22-55	-	-
	Mean	34.96 ± 6.17	35.08 ± 6.12	0.124	0.902
BMI (kg/m2)	-	19-24	19-24	-	-
	Mean	22.19 ± 1.37	22.07 ± 1.44	0.540	0.590
Education levels	High school	18	20	0.025	0.874
	Associate degree	26	27
	Bachelor's degree	36	33

BMI: Body mass index.

Table 2 Comparison of neuroendocrine axis indicators between different phenotypes of irritable bowel syndrome

	IBS-D	IBS-C	IBS-M	IBS-U	F value	P value
Number of cases	36	24	15	5	-	-
ACTH (ng/mL)	16.45 ± 2.41	16.33 ± 2.39	17.48 ± 2.37	16.78 ± 2.54	1.315	0.274
COR (pg/mL)	191.37 ± 20.11	189.81 ± 20.45	190.23 ± 20.47	189.46 ± 20.73	3.552	0.338
5-HT (ng/mL/mg)	0.52 ± 0.24	0.58 ± 0.34	0.54 ± 0.21	0.57 ± 0.246	0.452	0.638

IBS-D: Diarrhea predominant IBS; IBS-C: Constipation predominant IBS; IBS-M: Mixed-type IBS; IBS-U: Unspecified-type IBS; ACTH: Adrenocorticotropic hormone; COR: Cortisol; 5-HT: 5-hydroxytryptamine.

Table 3 Comparison of gut microbiota indicators between different phenotypes of irritable bowel syndrome

	IBS-D	IBS-C	IBS-M	IBS-U	F	P value
Number of cases	36	24	15	5	-	-
Bacteroides (lgCFU/g)	8.55 ± 0.75	8.62 ± 0.82	8.61 ± 0.90	8.70 ± 0.95	0.719	0.491
Lactobacillus (lgCFU/g)	7.47 ± 0.62	7.38 ± 0.48	7.65 ± 0.71	7.22 ± 0.59	5.872	0.430
Bifidobacterium (lgCFU/g)	6.23 ± 0.71	6.17 ± 0.56	5.96 ± 0.62	6.08 ± 0.48	6.754	0.217
Escherichia coli (lgCFU/g)	8.45 ± 0.66	8.58 ± 0.91	8.23 ± 0.83	8.64 ± 0.72	2.519	0.846
Enterococcus (lgCFU/g)	8.75 ± 0.83	8.92 ± 0.74	8.85 ± 1.02	8.28 ± 0.91	3.719	0.290

IBS-D: Diarrhea predominant IBS; IBS-C: Constipation predominant IBS; IBS-M: Mixed-type IBS; IBS-U: Unspecified-type IBS.

Table 4 Comparison of inflammatory factor levels between different phenotypes of irritable bowel syndrome

	IBS-D	IBS-C	IBS-M	IBS-U	F	P value
Number of cases	36	24	15	5	-	-
IL-6 (ng/L)	18.37 ± 4.76	22.05 ± 6.34	19.92 ± 4.98	20.68 ± 5.59	3.801	0.285
IL-8 (ng/L)	45.80 ± 12.56	59.23 ± 17.28	53.91 ± 15.03	49.77 ± 13.94	1.917	0.477
IL-10 (ng/L)	19.43 ± 7.82	28.15 ± 5.94	25.67 ± 6.32	22.08 ± 6.51	1.253	0.253

IBS-D: Diarrhea predominant IBS; IBS-C: Constipation predominant IBS; IBS-M: Mixed-type IBS; IBS-U: Unspecified-type IBS.

Table 5 Correlation of neuroendocrine axis with intestinal microbiota and inflammatory response in irritable bowel syndrome patients

	ACTH		COR
	r	P value	r	P value
Bacteroides	0.378	< 0.001	0.392	< 0.001
Lactobacillus	-0.359	< 0.001	-0.336	< 0.001
Bifidobacterium	-0.315	< 0.001	-0.348	< 0.001
Clostridium	-0.333	< 0.001	-0.329	< 0.001
Fusobacterium	-0.362	< 0.001	-0.347	< 0.001
IL-6	0.482	< 0.001	0.392	< 0.001
IL-8	0.513	< 0.001	0.496	< 0.001
IL-10	0.396	< 0.001	0.423	< 0.001

ACTH: Adrenocorticotropic hormone; COR: Cortisol.