The Bidirectional Link between Nutritional Factors and Inflammatory Bowel Diseases: Dietary Deficits, Habits, and Recommended Interventions—A Narrative Review

Abstract

Inflammatory bowel diseases comprise Crohn’s disease and ulcerative colitis, two chronic inflammatory disorders of the digestive tract that develop in adolescence and early adulthood and show a rising pattern in industrialized societies, as well as in developing countries, being strongly influenced by environmental pressures such as nutrition, pollution and lifestyle behaviors. Here, we provide a narrative review of the bidirectional link between nutritional factors and IBD, of dietary deficits observed in IBD patients due to both the disease itself and dietary habits, and of the suggested nutritional interventions. Research of the literature was conducted. Clinical and basic research studies consistently demonstrate that diet could alter the risk of developing IBD in predisposed individuals. On the other hand, dietary interventions represent a valid tool in support of conventional therapies to control IBD symptoms, rebalance states of malnutrition, promote/maintain clinical remission and improve patients’ quality of life. Although there are no official dietary guidelines for patients with IBD, they should receive nutritional advice and undergo oral, enteral, or parenteral nutritional supplementation if needed. However, the dietary management of malnutrition in IBD patients is complex; future clinical studies are required to standardize its management.

Nutritional Biomarkers for the Prediction of Response to Anti-TNF-α Therapy in Crohn’s Disease: New Tools for New Approaches

“…The percentage of total daily calories derived from ultra-processed (UP) foods that may interfere with IBD progression or remission [ 6 ] were not significantly different comparing patients in remission to those still active at V3 and at V1 and ranged between 15% and 17% at V1, and between 20% and 22% at V3 ( see Supplementary File S2, Figure S1A –D). These values are in line with the average value of 13% reported in 2022 for the Italian population [ 14 ].…”

“…Nevertheless, the role of nutrients in the clinical management of CD patients has not yet been fully investigated. Data reported in the literature mainly concern surveys on dietary habits in patients with IBD or focus on interventional studies in CD patients aimed at evaluating the effectiveness of specific dietary protocols to aid or to maintain clinical remission [ 6 ]. Our research group had already highlighted substantial differences in the nutrient intake of subjects with Crohn’s disease in comparison with healthy subjects [ 7 ].…”

Fat and proteolysis due to methionine, tryptophan, and niacin deficiency leads to alterations in gut microbiota and immune modulation in inflammatory bowel disease

“…Diet is closely related to the development of IBD, and diets centered on high‐protein meats, fatty foods, and sugary drinks have been shown to increase the risk of IBD. 17 Therefore, it is important to identify natural ingredients and dietary practices that regulate the intestinal environment that are effective in alleviating IBD symptoms. It has been reported that methionine metabolism is abnormal in IBD, with methionine levels in intestinal mucus are elevated in IBD patients, 18 whereas methionine deficiency regulates the expression of IBD‐related genes in animal models of IBD.…”