The Effect of a Low FODMAP Diet in Functional Dyspepsia Patients With Meal Related Symptoms on Complaint Pattern and Urinary Histamine Excretion

What this Trial Is About

Researchers are studying the effects of a low-FODMAP diet on patients with functional dyspepsia (FD), a condition causing upper digestive symptoms like fullness, pain, and burning without an obvious organic cause. The study aims to see if this diet can reduce these symptoms and understand how it might work, focusing on duodenal changes and urinary histamine levels related to FD. Functional dyspepsia is common and can significantly impact daily life and healthcare costs, especially in patients with severe symptoms and psychosocial effects. Participants will follow a structured dietary plan starting with a 2-week baseline period, followed by 6 weeks on a strict low-FODMAP diet. Next, a 5-week single-blind reintroduction phase tests individual FODMAP groups and a control substance. Finally, a 2-week moderate FODMAP diet phase allows consumption of non-triggering FODMAPs. The study provides educational materials and recipes to support diet adherence. Urine samples and duodenal biopsies are collected before and after the strict diet to examine physiological changes. During the study, participants will have symptom assessments using the Leuven-postprandial distress scale before and after the diet. Researchers will measure urinary histamine, N-methylhistamine, duodenal mucosal integrity, and low-grade inflammation to explore diet effects. Endoscopies and 24-hour urine collections occur at baseline and after six weeks. The total participation includes about 15 weeks of dietary phases and monitoring, allowing detailed evaluation of symptom changes and biological responses.

Low FODMAP Diet in FD (PDS)