Adherence to the pro-inflammatory diet in relation to prevalence of irritable bowel syndrome.

OBJECTIVE: There is no prior study that examined the association between nutrient-based dietary inflammatory index (DII) and odds of Irritable Bowel Syndrome (IBS). We examined the association between DII score and odds of IBS and its severity among Iranian adults.

METHODS: In this cross-sectional study, dietary intakes of 3363 Iranian adults were examined using a validated Dish-based 106-item Semi-quantitative Food Frequency Questionnaire (DS-FFQ). DII was calculated based on dietary intakes derived from DS-FFQ. IBS was assessed using a modified Persian version of Rome III questionnaire.

RESULTS: After adjustment for potential confounders, we found that participants in the highest quintile of DII score had greater chance for IBS compared with those in the lowest quintile (OR: 1.36; 95% CI: 1.03-1.80). By gender, we found a significant association between DII score and IBS among women (OR: 1.41; 95% CI: 1.00-2.00). By BMI status, overweight or obese (BMI ≥ 25 kg/m2 ) individuals in top quintile of DII score had greater odds for IBS than those in the bottom quintile (OR: 1.64; 95% CI: 1.07-2.53). No significant association was observed between a pro-inflammatory diet and severity of IBS symptoms.

CONCLUSIONS: Consumption of a pro-inflammatory diet was associated with increased odds of IBS, in particular among women and those with BMI ≥ 25 kg/m2 .