Intestinal inflammatory profile shows increase in a diversity of biomarkers in irritable bowel syndrome

Abstract

Background: It has been proposed that irritable bowel syndrome (IBS) is a low-grade mucosal inflammatory disease.

Objective: To characterize the intestinal inflammatory profile in IBS patients with or without fructose intolerance.

Design: Patients referred to colonoscopy with IBS complaints were screened for participation. IBS patients diagnosed according to the Rome II criteria and with no organic gastrointestinal disease were included in the study. One subgroup was patients included in a fructose-reduced diet study for 2 months with effects based on VAS symptom scores. Healthy controls were subjects under investigation of colorectal cancer screening with no IBS or other gastrointestinal diseases. All patients included had normal histology from rectum. Mucosal cytokines, chemokines and growth factors were measured by multiplex technology.

Results: Of 27 inflammatory markers tested in the mucosal tissue, 13 were significantly increased and none was significantly decreased in IBS as compared to controls. Significantly increased were the proinflammatory cytokines tumor necrosis factor, the typical TH1 markers IFNγ, IL-1β, IL-2 and RANTES, the typical TH2 markers IL-5 and IL-9, the TH17 marker IL-17, TNF, the pleiotropic IL-15, and the growth factors bFGF and GM-CSF. In IBS patients with fructose intolerance only IL-5 was significantly increased compared to patients without fructose intolerance.

Conclusions: A dysregulated mucosal inflammatory profile with an increased level of TH1, TH2 and TH17 markers, and growth factors were observed in bowel mucosa in of IBS patients when compared to healthy controls.

Keywords:

• Chemokine
• cytokine
• fructose intolerance
• functional bowel disease
• growth factor

Acknowledgements

The authors thank for our colleagues at the Departments of Gastroenterology at Hospital of Helgeland, Rana; Nordlandssykehuset, Bodø; and University Hospital North Norway, Tromsø, Norway in support in recruiting patients. Guarantor of article: Jon Florholmen.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

The project was funded by the Northern Norway Regional Health Authority (ID Helse Nord RHF), the Gastro Fund, University Hospital North Norway, Helgeland Hospitals Research Committee, The Odd Fellow Foundation and the European Community’s Seventh Framework Programme under grant agreement 602699 (DIREKT).