Background
Micro‐inflammation is involved in the pathogenesis of irritable bowel syndrome (IBS). The parasympathetic nervous system, via acetylcholine (ACh), and its hydrolytic enzymes, plays a role in regulating inflammation. Increased serum cholinesterase activity, named cholinergic Status (CS), is associated with decreased inflammatory inhibition (ie, pro‐inflammation). We assessed the association between IBS diarrhea‐predominant (IBS‐D) symptoms, CS, and inflammatory biomarkers.
Methods
Women with IBS‐D were prospectively recruited. Serum acetylcholinesterase (AChE), CS, and high‐sensitivity C‐reactive protein (hs‐CRP) levels were analyzed and fecal calprotectin (FC) in a subgroup of patients. The control group included women attending routine health checkups (matched by age and BMI).
Key Results
Ninety‐four women with IBS‐D were compared to matched controls (1:1). Serum CS, AChE, and the AChE/butyrylcholinesterase (BChE) ratios were significantly increased in the IBS‐D group compared to matched controls (P = 0.018, P = 0.001, and P = 0.004, respectively). Using a multiple logistic regression model, IBS‐D was almost twice as likely in women with high CS compared to women with low CS (adjusted OR=1.84 (95% CI: 1.01‐3.33), P = 0.045). Furthermore, IBS‐D patients with higher hs‐CRP levels demonstrated lower CS and BChE activity and elevated AChE and AChE/BChE ratios compared to patients with lower hs‐CRP levels (P = 0.026, P = 0.036, P = 0.002; and P = 0.0007, respectively). CS was not correlated with the IBS symptoms score.
Conclusions and Inferences
This is the first study to explore the potential role of serum CS in IBS‐D. The findings emphasize the possible role of the autonomic nervous system and its anti‐inflammatory properties in IBS.