Patients with Inflammatory Bowel Disease (IBD) exhibit a dysregulated immune response that may be further exacerbated by bioactive compounds, such as histamine. Current dietary guidelines for IBD primarily focus on symptom management and flare-up prevention, yet targeted nutritional strategies addressing histamine metabolism remain largely unexplored. This narrative review aims to summarize the existing literature on the complex interplay between IBD and histamine metabolism and propose a novel dietary framework for managing IBD progression in patients with histamine intolerance (HIT). Relevant studies were identified through a comprehensive literature search of PubMed/MEDLINE, Google Scholar, ScienceDirect, Scopus, and Web of Science. The proposed low-histamine diet (LHD) aims to reduce the overall histamine burden in the body through two primary strategies: (1) minimizing exogenous intake by limiting high-histamine and histamine-releasing foods and (2) reducing endogenous histamine production by modulating gut microbiota composition, specifically targeting histamine-producing bacteria. In parallel, identifying individuals who are histamine-intolerant and understanding the role of histamine-degrading enzymes, such as diamine oxidase (DAO) and histamine-N-methyltransferase (HNMT), are emerging as important areas of focus. Despite growing interest in the role of histamine and mast cell activation in gut inflammation, no clinical trials have investigated the effects of a low-histamine diet in IBD populations. Therefore, future research should prioritize the implementation of LHD interventions in IBD patients to evaluate their generalizability and clinical applicability.

Patients with Inflammatory Bowel Disease (IBD) exhibit a dysregulated immune response that may be further exacerbated by bioactive compounds such as histamine. Current dietary guidelines for IBD primarily focus on symptom management and flare-up prevention, yet targeted nutritional strategies addressing histamine metabolism remain largely unexplored. This narrative review aims to summarize existing literature on the complex interplay between IBD and histamine metabolism and to propose a novel dietary framework for managing IBD progression in patients with histamine intolerance. Relevant studies were identified through a comprehensive literature search in PubMed/MEDLINE, Google Scholar, ScienceDirect, Scopus, and Web of Science. The proposed low-histamine diet (LHD) aims to reduce the overall histamine burden in the body through two primary strategies: (1) minimizing exogenous intake by limiting high-histamine and histamine-releasing foods, and (2) reducing endogenous histamine production by modulating gut microbiota composition, specifically targeting histamine-producing bacteria. In parallel, identifying histamine-intolerant individuals and understanding the role of histamine-degrading enzymes, such as diamine oxidase (DAO) and histamine-N-methyltransferase (HNMT), are emerging as important areas of focus. Despite growing interest in the role of histamine and mast cell activation in gut inflammation, no clinical trials have investigated the effects of a low-histamine diet in IBD populations. Therefore, future research should prioritize the implementation of LHD interventions in IBD patients to evaluate their generalizability and clinical applicability.

Background/Objectives: Enteral nutrition (EN), delivered either exclusively (EEN) or partially (PEN) in combination with the Crohn’s Disease Exclusion Diet (CDED), represents an evidence-based dietary therapy for active Crohn’s Disease (CD), recommended in clinical guidelines. However, adherence to this therapy remains suboptimal among adult patients. This study aimed to explore the intention to repeat CDED & PEN alongside perceived factors affecting adherence to CDED & PEN in CD adult patients. Methods: A single-center, cross-sectional qualitative study was conducted between October 2025 and March 2026 at a private dietetic practice in Larissa, Greece. Semi-structured interviews were undertaken and analyzed using thematic analysis. Results: Out of the 88 patients screened, 15 adults with CD participated in semi-structured interviews. Four overarching themes emerged: (1) intention to repeat CDED & PEN, with all participants reporting willingness to repeat CDED & PEN in the event of future relapse; (2) barriers to CDED & PEN adherence, including challenges in social situations involving food; (3) facilitators of CDED & PEN adherence, such as improved symptom control and increased sense of security; and (4) dual factors affecting CDED & PEN adherence, whereby meal preparation demands, taste and variety, and social and environmental support acted as either facilitators or barriers against adherence depending on individual circumstances. Conclusions: Greek adults with CD showed strong willingness to reinitiate CDED & PEN during relapse. Addressing modifiable barriers, particularly dietary monotony and financial burden, alongside strengthening structured dietitian support and personalized dietary guidance, may help optimize adherence in clinical practice.

Background/Objectives: Enteral nutrition (EN), delivered either exclusively (EEN) or partially (PEN) in combination with the Crohn’s Disease Exclusion Diet (CDED), represents an evidence-based dietary therapy for active Crohn’s Disease (CD), recommended in clinical guidelines. However, adherence to this therapy remains suboptimal among adult patients. This study aimed to explore the intention to repeat CDED & PEN alongside perceived factors affecting adherence to CDED & PEN in CD adult patients. Methods: A cross-sectional qualitative study was conducted. Semi-structured interviews were undertaken and analysed using thematic analysis. Results: Out of the 88 patients screened, 15 adults with CD participated in semi-structured interviews. Four overarching themes emerged: (1) intention to repeat PEN & CDED, with all participants reporting willingness to repeat CDED & PEN in the event of future relapse; (2) barriers to CDED & PEN adherence, including challenges in social situations involving food; (3) facilitators of CDED & PEN adherence, such as improved symptom control and increased sense of security; and (4) dual factors affecting CDED & PEN adherence, whereby meal preparation demands, taste and variety, and social and environmental support acted as either facilitators or barriers against adherence depending on individual circumstances. Conclusions: Greek adults with CD showed strong willingness to reinitiate CDED and PEN during relapse. Addressing modifiable barriers, particularly dietary monotony and financial burden, alongside strengthening structured dietitian support and personalized dietary guidance, may help optimize adherence in clinical practice.