Table 3.

IBS symptom severity scores and BDNF levels according to sex.

Parameter	Group
	Control (n = 10)			IBS (n = 20)
	Women (n = 2)	Men (n = 8)	p	Women (n = 14)	Men (n = 6)	p
IBS-SSS	21.5 ± 19.5 (2–41)	29.3 ± 10.1 (0–72)	n.c.	293.7 ± 23.0 (124–439)	361.8 ± 39.8 (220–486)	0.133
BDNF mRNA (arbitrary unit)	8.1 ± 1.4 (6.7–9.4)	10.2 ± 1.2 (7.5–16.8)	n.c.	13.2 ± 3.6 (1.4–48.1)	4.7 ± 1.1 (1.9–8.6)	0.048
BDNF protein (ng/mg)	2.7 ± 1.6 (1.1–4.3)	1.5 ± 0.1 (0.9–1.9)	n.c.	2.0 ± 0.3 (0.6–3.4)	1.2 ± 0.2 (0.6–1.8)	0.076

BDNF levels were assessed using nCounter analysis and ELISA and corrected for housekeeping gene expression or total tissue protein, respectively. Data are presented as mean ± sem, the range is indicated in parentheses. Normality was assessed using the Kolmogorow-Smirnov test. Differences were assessed using t-tests or the Mann-Whitney-U test depending on the distribution of the data. Significant differences are displayed in bold. BDNF, brain-derived neurotrophic factor; IBS, irritable bowel syndrome; IBS-SSS, IBS Symptom Severity Score; n.c., not calculated.