Nutrition as a Therapeutic Tool in the Management of Inflammatory Bowel Disease

Author: Hannah J. Moir

Support statement: The writing and publication of this news feature was supported by Viatris, who were not involved in the creation of this content.

December marks the Annual Crohn’s and Colitis Awareness Week, which is a great opportunity to educate people about these two inflammatory bowel diseases (IBD), and raise awareness about their impact on individuals. The clinical care of IBD focuses on reducing inflammation and symptom reoccurrence, to achieve symptom remission and mucosal healing.

However, IBD is often associated with malnutrition, a condition where the imbalance of energy, protein, and other micronutrients can adversely affect function; clinical outcomes; and body composition, such as the loss of lean mass or fat-free mass, and skeletal muscle mass, even with a normal BMI.¹ Those with IBD often have dietary restrictions, nutritional deficiencies, and micronutrient inadequacies, which can negatively impact their physical activity and quality of life.^1,2

A multidisciplinary team with an integrated dietician is key to supporting patients with IBD, in order to improve nutritional therapy, and to avoid malnutrition and nutrient-related disorders.³

NUTRITIONAL CHALLENGES IN CROHN’S DISEASE AND ULCERATIVE COLITIS

The INTICO2 cohort study, presented at the United European Gastroenterology (UEG) Week 2023, identified the nutritional risk factors and nutritional status of adults with Crohn’s disease during disease remission.² This observational study identified that adult Crohn’s disease outpatients reported an average of 4±3 dietary impact factors, such as food restriction and impaired appetite, with 92% (180/196) reporting at least one such factor.² Food restriction was reported by 34% (67/196) of patients, with dairy, wheat, red meat, pulses, garlic, and onion identified as the most restricted food items.² An analysis of food diaries reported inadequacy of dietary micronutrients, with an average of 6±4 nutrients falling below the Lower Reference Nutrient Intake (LRNI) threshold. Additionally, 30% (57/192) of participants reported impaired appetite.² This study identified a correlation between a higher number of dietary impact factors, associated with a lower fat-free mass index (R=-0.214; P=0.003), and a higher number of nutrients consumed below the LRNI (R=0.201; P=0.005).²

Unfortunately, conventional methods of assessing nutritional support needs rely on body weight and BMI, which do not consider gastrointestinal symptoms that may limit food intake.⁴ Consequently, potentially undiagnosed nutritional issues, such as food restriction and impaired appetite, may persist among adults with Crohn’s disease during clinical remission, potentially contributing to inadequate micronutrient intake (R=0.201; P=0.005), lower fat-free mass (R=-0.214; P=0.003), and muscle function (R=-0.255; P<0.001).²

EXPLORING NUTRITIONAL THERAPY GUIDELINE RECOMMENDATIONS FOR INFLAMMATORY BOWEL DISEASE

There is increasing evidence that suggests that changes in diet (introduction or elimination of certain dietary elements) can have a positive therapeutic effect on IBD. For instance, dietary interventions have been found to be effective in treating Crohn’s disease in children, and there is also a growing body of evidence supporting its use in adults for inducing and maintaining remission.⁵ However, the use of nutritional therapy in IBD, specifically in ulcerative colitis, is not well researched, and there are currently limited recommendations for its implementation into clinical practice.^5,6

The use of nutritional therapy has several advantages over standard therapy, including a low side effect profile and cost-effectiveness, and many people see dietary therapy as an alternative or complementary treatment approach to conventional IBD management, yet it is still underused in practice.⁷

The European Society for Clinical Nutrition and Metabolism (ESPEN) guideline encourages those with IBD to consume a varied diet that meets their energy, macronutrient, and micronutrient requirements.³ According to Stephan Bischoff, Full Professor and Director of the Department of Nutritional Medicine and Prevention at the University of Hohenheim, Stuttgart, Germany, who presented the recent updates of the ESPEN guideline during UEG Week 2023, modifiable factors that affect IBD include iron, electrolyte balance, vitamin D, and vitamin B12. He also postulated whether nutrition can be used to prevent or treat IBD.

The Significance of Vitamin D in Inflammatory Bowel Disease

A study presented at UEG Week 2023 identified that vitamin D (serum 25-hydroxyvitamin D [25 (OH)D]) deficiency is associated with decreased long-term response to anti-TNFα therapy in paediatric patients with IBD.⁸

Multivariate analysis found that vitamin D levels above 30 ng/ml were significantly associated with clinical response (hazard ratio: 3.92; 95% confidence interval: 1.52–10.08; p=0.005) and remission (hazard ratio: 5.23; 95% confidence interval: 1.88–14.55; p=0.002).⁸ While anti-TNFα trough levels were similar between vitamin D-deficient and non-deficient children under 18 years of age, intensification of anti-TNFα therapy was more prevalent among vitamin D-deficient children (64.6% versus 21.1%; p<0.001), as was discontinuation of anti-TNFα therapy (32.3% versus 10.5%, p=0.061).⁸

However, prospective studies are needed to determine whether supplementation of vitamin D can improve IBD outcomes under anti-TNFα therapy, as conflicting perspectives exist with regards to adult IBD.⁹

THE ROLE OF NUTRIENTS IN INFLAMMATORY BOWEL DISEASE

In adjuvant therapy, diet and nutrition play an important role in managing IBD. Certain types of foods, such as processed foods, cheese, and high-fat, high-protein foods, can increase the levels of inflammatory factors such as TNF-α and IL-β, which can lead to intestinal inflammation.¹⁰ On the other hand, consuming vegetables, fruits, fibres, nuts, olive oil, fish, and yoghurt increase the levels of short-chain fatty acids and polyphenols, which are anti-inflammatory and antioxidant.¹⁰ These elements can help to maintain intestinal microecological balance.¹⁰

The updated ESPEN guideline recommends a diet rich in fruit, vegetables, and ω-3 fatty acids, and low in ω-6 fatty acids, to prevent IBD.³ However, ω-3 supplementation is not advised to maintain remission.³

The guideline also advises against consuming ultra-processed food and dietary emulsifiers, as they may increase the risk of IBD.³

Those patients with IBD that are in remission, or experiencing mild active disease, may benefit from certain dietary patterns, including enteral nutrition, which involves receiving all nutritional intake through a formula for up to 12 weeks, delivered orally via a nasogastric tube, or a gastrostomy tube. Another option is the low FODMAP diet, which involves having a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. Whole foods-based exclusion diets, like the Crohn’s disease exclusion diet (CDED), can also help to avoid or reduce exposure to foods containing animal/dairy fat, high fat from other sources, wheat, red or processed meat, protein sources rich in taurine, emulsifiers including carrageenans (red edible seaweed), artificial sweeteners, and sulphites.⁷ Additionally, the Mediterranean diet, consisting of a high intake of vegetables, fruits, cereals, nuts, legumes, and unsaturated fats, can help to maintain a healthy diet for those with IBD.^10,11 However, data supporting the use of dietary therapy in adults with IBD is not as strong as in paediatric IBD.^7,11

Presented during UEG Week 2023, a systematic review exploring the role of the anti-inflammatory diet for IBD (IBD-AID) in ulcerative colitis was performed, to help clinicians make more informed decisions.⁶ The findings reported a statistically and clinically significant positive therapeutic effect, and stated that IBD-AID could induce and maintain remission, reduce colectomy rates, and improve patient quality of life in ulcerative colitis.⁶ Efficacy was shown in mild, moderate, and severe forms of ulcerative colitis, and when initiated as either a monotherapy or adjunct with conventional therapy, it was efficacious in reducing ulcerative colitis disease severity for both patient-reported symptoms and endoscopically or biochemically observed signs.⁶

GUIDELINE RECOMMENDATIONS FOR THE PREVENTION OF MALNUTRITION

The ESPEN guidelines also recommend that those diagnosed with IBD should be screened for malnutrition, which should be treated appropriately. Treatment may include advice on energy intake (30–35 kcal/kg/day, although an individual calculation should be determined), protein (1.2–1.5 g/kg/day in active IBD, and 1 g/kg/day in remission), micronutrient deficiencies, and iron supplementation in those with iron deficient anaemia. Malnutrition worsens disease prognosis, complication rates, mortality, and quality of life.³

Role of Anti-TNF Therapy in Reducing the Risks of Malnutrition in Inflammatory Bowel Disease

Interestingly, a retrospective study published in February 2023 found that anti-TNF therapy has can have a positive impact on the long-term nutritional status of patients with Crohn’s disease, and can even reverse malnutrition.¹ The study, which analysed 115 patients with Crohn’s disease, identified that early use of anti-TNF therapy can significantly affect skeletal muscle mass, fat mass, and bone mineral content, thereby supporting the patient’s long-term nutritional status, and reducing the likelihood of malnutrition.¹

This suggests that anti-TNF therapy may have a potential positive effect on sarcopenia by reducing inflammation and catabolism in skeletal muscles, although more research is required to confirm this. Overall, the study highlights the potential of therapeutic treatments with anti-TNF to improve the nutritional status of patients with IBD.

Importance of Gut Microbiota in Inflammatory Bowel Disease

One of the significant consequences of IBD is the impact on gut absorbance, with patients not adequately ingesting or absorbing nutrients, and an association to the lack of important gut microbes.¹² A deficiency in gut bacteria that possess anti-inflammatory abilities is also observed to be reduced in IBD, which consequently exacerbates symptoms of IBD.¹³ This raises the question of whether nutritional supplementation or replacing gut bacteria is important for the treatment of conditions such as IBD.

Dietary practices, such as the IBD-AID diet, may benefit those with IBD, and help to restore the balance of gut bacteria, aiming for symptom remission.¹⁰ This diet consists of three phases: probiotics; the avoidance of high lactose, refined sugars, wheat, and corn, which can be detrimental to gut bacteria; and consuming a well-balanced diet of lean proteins, vegetables, and fruits, while also avoiding saturated and trans fats, added salt, and sugar.

It is important to note, that the current ESPEN and Canadian Guidelines do not recommend the use of prebiotics or probiotics in IBD for gut health,^3,7 although selected probiotics or probiotic-containing preparations can be used as an alternative to 5-aminosalicylic acid standard therapy, if not well tolerated.³

For more information and support, the UEG and ESPEN have released an IBD Guideline App for smartphones and tablets, for all healthcare professionals.

References

1. Wang Y et al. Earlier anti-TNF therapy reduces the risk of malnutrition associated with alterations in body composition in patients with Crohn’s disease. Front Nutr. 2023;10:
2. Westoby C et al. Dietary impact factors, food restriction and dietary inadequacies during adult Crohn’s disease remission: the INTICO2 cohort study. UEG J. 2023;11(Suppl 8):782.
3. Bischoff SC et al. ESPEN guideline on Clinical Nutrition in inflammatory bowel disease. Clin Nutr. 2023;42(3):352-79.
4. Mcdonnell M et al. P67 Body composition and health-related quality of life in adult crohn’s disease during clinical remission: the INTICO2 cohort study. 2023;72:A82-3.
5. Sheth A et al. PP0471 Nutrition therapy compared to standard therapy in Crohn’s disease. UEG J. 2023;11(Suppl 8):790-1.
6. Sartie S et al. PP0443 Nutrition therapy in ulcerative colitis, a systematic review. UEG J. 2023;11(Suppl 8):774.
7. Murthy SK et al. The 2023 impact of inflammatory bowel disease in Canada: treatment landscape. J Can Assoc Gastroenterol. 2023;6(Suppl 2):S97-110.
8. Yerushalmy Feler A et al. PP0875 Vitamin D deficiency is associated with poor disease outcome under anti-TNF therapy in children with IBD. UEG J. 2023;11(Suppl 8):1041-2.
9. Chanchlani N et al. ; PANTS Consortium. Pretreatment vitamin D concentrations do not predict therapeutic outcome to anti-TNF therapies in biologic-naïve patients with active luminal Crohn’s disease. Crohns Colitis 360. 2023:5(3):otad026.
10. Hou Y et al. Comparison and recommendation of dietary patterns based on nutrients for Eastern and Western patients with inflammatory bowel disease. Front Nutr. 2023:9:1066252.
11. Fitzpatrick JA et al. Dietary management of adults with IBD – the emerging role of dietary therapy. Nat Rev Gastroenterol Hepatol. 2022;19(10):652-69.
12. Elzayat H et al. Unraveling the impact of gut and oral microbiome on gut health in inflammatory bowel diseases. Nutrients. 2023;15(15):3377.
13. Haneishi Y et al. (2023). Inflammatory bowel diseases and gut microbiota. Int J Mol Sci. 2023;24(4):3817.