Objective: Among patients with disorders of gut-brain interaction (DGBI), food intake is a known symptom trigger and dietary modifications are encouraged as a first line treatment. Although the current dietary management approaches promote healthy eating patterns, the evidence of their efficacy is lacking. Here, we aimed to explore if certain eating habits are associated with gastrointestinal (GI) symptoms, and which specific foods are identified as triggers of GI symptoms among participants with functional dyspepsia (FD), irritable bowel syndrome (IBS), and a control group.
Methods: A population-based online survey was conducted including 825 women and men aged 18-70 years who met minimum Rome IV diagnostic symptom frequency thresholds for at least one bowel symptom used to diagnose a functional bowel disorder. An age- and sex-matched control group without bowel symptoms was also recruited from the general Swedish population (n=1738). The survey included questions on demographics, dietary preferences, eating speed, liquid intake during meals and meal frequency per day. An adapted food frequency questionnaire that assesses intakes of 38 commonly consumed food items was used. For each food, participants had to answer whether they considered the specific food to be a trigger for GI symptoms. IBS symptom severity was assessed with the IBS severity scoring system.
Results: In total, n=159 fulfilled the Rome IV criteria for FD and n=136 for IBS, hereafter referred to as patients. Adhering to any special diet was more common in patients compared to controls (p<0.001) (Table). Eating speed or meals/day did not differ significantly between patients and controls. The controls reported drinking less liquids during mealtime compared to patients with FD (p=0.027).
Among patients, neither eating speed, liquid intake during meals, nor the number of meals/day were significantly associated with IBS symptom severity. When dividing patients into non-frequent meal consumers (NFMC, mean 1.8 ± 0.4) and frequent meal consumers (FMC, mean 4.1 ± 1.3), NFMC reported that IBS interfered with their daily life more compared to FMC (p<0.001). Foods that were least commonly reported to cause GI symptoms in patients included hard bread, fish, berries, and seeds (Figure). The most frequently reported food triggers include pizza, crisps, ice cream, white bread, and dairy. Having overlapping IBS and FD increased the prevalence of foods that were considered to cause symptoms.
Conclusion: In this cross-sectional study, no clear associations between eating patterns and GI symptoms were noted. In patients with FD and IBS, food items associated with a healthy Nordic diet were less commonly reported to cause GI symptoms, whereas junk foods were more commonly reported to cause GI symptoms. Promoting healthy food choices seems compatible with dietary treatment of patients with FD and IBS.

