Psychological comorbidity increases the risk for postinfectious IBS partly by enhanced susceptibility to develop infectious gastroenteritis.

Psychological factors increase the risk to develop postinfectious IBS (PI-IBS), but the mechanisms involved are unclear. As stress affects the immune system, we investigated the potential interaction between psychological factors, the immune response against infectious gastroenteritis (IGE) and the development of IGE and PI-IBS in a large cohort exposed to contaminated drinking water. 18 620 people exposed to contaminated drinking water (norovirus, Giardia lamblia, Campylobacter jejuni) were invited to participate in a prospective controlled cohort study. They were asked to complete questionnaires assessing demographic, psychological and clinical data during the outbreak and 1 year later. At both time points, in-depth immune function (peripheral blood and rectal biopsies) was studied in a subgroup of subjects. 1379 subjects completed the questionnaires during the outbreak, of which 271 developed IGE. Risk factors for IGE included younger age, pre-existing dyspepsia-like symptoms, anxiety and drinking contaminated tap water. Anxiety scores before the outbreak inversely correlated with interleukin-2-expressing CD4+ T cells (r=0.6, p=0.01, n=23). At follow-up, 34 of 172 (20%) IGE subjects developed IBS compared with 24/366 exposed participants (7%, p<0.0001, χ(2) test). A Th2 cytokine phenotype at time of infection was associated with increased risk for PI-IBS 1 year later. Except for increased B cell numbers, no evidence for systemic or rectal mucosal immune activation in PI-IBS was demonstrated at follow-up. Our study shows that the increased risk of patients with psychological comorbidity to develop PI-IBS may partly result from an increased susceptibility to develop IGE, possibly resulting from a Th2-immune bias. (ClinicalTrials.gov NCT01497847).

Wouters MM ，Van Wanrooy S ，Nguyen A ，Dooley J ，Aguilera-Lizarraga J ，Van Brabant W ，Garcia-Perez JE ，Van Oudenhove L ，Van Ranst M ，Verhaegen J ，Liston A ，Boeckxstaens G ... -  《-》

Post-infectious irritable bowel syndrome following water contamination.

Marshall JK 《-》

Psychometric scores and persistence of irritable bowel after Campylobacter concisus infection.

Nielsen HL ，Engberg J ，Ejlertsen T ，Nielsen H ... -  《-》

Incidence and epidemiology of irritable bowel syndrome after a large waterborne outbreak of bacterial dysentery.

Marshall JK ，Thabane M ，Garg AX ，Clark WF ，Salvadori M ，Collins SM ，Walkerton Health Study Investigators ... -  《-》

An outbreak of acute bacterial gastroenteritis is associated with an increased incidence of irritable bowel syndrome in children.

Thabane M ，Simunovic M ，Akhtar-Danesh N ，Garg AX ，Clark WF ，Collins SM ，Salvadori M ，Marshall JK ... -  《-》