The Relationship of Dietary Nutrient Patterns and Irritable Bowel Syndrome: A Multicenter Case-Control Study

Despite the connotations between some dietary patterns and irritable bowel syndrome (IBS), we are aware of no study about the link between IBS and patterns of nutrient intake. This study aimed to investigate the association between nutrient-based dietary patterns and IBS in the Iranian adult population. This multicenter case-control study was conducted across three states in the west of Iran from 2021 to 2023. In this study, 317 patients with IBS and 601 healthy people were selected from the companions of other patients as a control group. Participants' dietary habits were evaluated using the validated and reliable 168-item food frequency questionnaire (FFQ). The severity of extra-intestinal IBS symptoms was measured using the Extra-Intestinal Symptoms Severity Scale (EISSS). Three nutrient patterns were as follows: The first nutrient pattern was high in β-carotene, vitamin C, vitamin A, α-carotene, lutein, beta-cryptoxanthin, lycopene, and vitamin E. The second nutrient pattern was rich in maltose, total fiber, glucose, and fructose. The third nutrient pattern included high consumption of sugars, sucrose, galactose, lactose, and caffeine. Logistic regression analysis after adjusting for the confounding variables showed that participants with higher adherence to pattern I (OR 0.75, 95% CI 0.62-0.92, p value 0.00) and pattern II (OR 0.52, 95% CI 0.42-0.64, p value 0.00) had lower odds of IBS. However, there was no significant connection between the third nutrient pattern and IBS (OR 0.95, 95% CI 0.80-1.12, p value > 0.05). Our study found that following nutrient patterns high in antioxidants, as well as those rich in monosaccharides and fiber, was primarily associated with lower odds of IBS.