The Crohn's Disease Exclusion Diet With Early Dairy Introduction vs Partial Enteral Nutrition for Crohn's Disease

Crohn's disease (CD) is a chronic relapsing inflammatory bowel disease that has a significant impact on patients' quality of life and is of increased incidence worldwide. The disease aetiology is complex and not fully understood. Accumulated data indicate that environmental factors, including diet, might play a key role in the pathogenesis and inflammation, through mechanisms involving gut dysbiosis, in genetically susceptible people. Epidemiological data suggest that a Mediterranean dietary pattern is associated with decreased risk for CD, whereas a Western diet, rich in animal fat, processed foods and food additives, seems to be linked with an increased disease risk.

Exclusive Enteral Nutrition (EEN) is the only well-established dietary therapy in CD and is used as the first line therapy for the induction of remission in mild to moderate pediatric CD. Evidence according to EEN efficacy in adults is not consistent, which could partly be explained by the compliance difficulty. It is of interest, that feacal inflammation increases rapidly after food re-introduction following EEN in children. Partial enteral nutrition (PEN) has been shown to be beneficial in maintaining remission, but poor compliance due to low formula palatability and patients' fatigue remains an important barrier in the clinical practice. Moreover, PEN is inferior to EEN in inducing remission. Crohn's Disease Exclusion Diet (CDED), which eliminates specific dietary components hypothesized to induce dysbiosis, appears to be effective in inducing and maintaining remission both in pediatric and adult populations. In parallel, patients express a strong interest in ways to manage their disease through diet, so the establishment of a palatable and as flexible as possible dietary pattern, not merely for inducing remission, but also as a feasible maintenance strategy is one of the main priorities in CD research at present.

Therefore, the aim of this study is to explore the effectiveness of the CDED and PEN in both inducing and maintaining remission of CD in adults. The investigators also wish to challenge patients with an early exposure to dairy products, to assess tolerability, prospecting for the development of a more flexible dietary approach based on the CDED principles. The investigators aim to assess the intervention effect on CD activity, based on routinely used clinical indices, blood and faecal inflammatory biomarkers (CRP, FC), health-related quality of life, nutritional status and dietary intake, in patients with mildly active CD.