DDW 2024 Nutritional Highlights (part 2): Diets for IBD and Noninflammatory Symptoms and the Potential of Microbiome-Directed Personalized Nutrition

The role of whole foods diets in IBD treatment, restrictive and non-restrictive diets for IBS-like symptoms, and microbiome-directed personalized nutrition were central themes at Digestive Disease Week 2024. Find out more about the latest research and discoveries (Part 2).

Diet for IBD Treatment

Benefits of a Catered Low-Fat, High-Fiber Diet to Manage Crohn’s Disease

While the first dietary intervention to induce remission for Crohn’s disease (CD) is exclusive enteral nutrition (EEN), this diet can be challenging to maintain for some patients. As a result, other novel diets are emerging as candidates for induction therapy. Hajar Hazime, PhD, who trained at Maria T. Abreu’s Lab at the University of Miami Miller Health System Sylvester Comprehensive Cancer Center, presented findings showing providing patients with CD in remission with a catered low-fat, high-fiber diet (Mi-IBD diet) for 8 weeks was easy to follow and well tolerated. The Mi-IBD diet emphasized consuming diverse sources of soluble and insoluble fiber (e.g., fruits and vegetables) while avoiding fried foods and excessive animal fat. It consisted of 20% of total calories from fat, an omega-6/omega-3 fatty acid ratio of 1:1, and 25-35 g of fiber per day. One group of patients only received one-time dietary counseling, a second group received catered food with the Mi-IBD diet, and a third group received catered food plus psychological support throughout the study. 

Patients with a catered diet were highly complaint (over 95% of dietary adherence) and reported significant improvements in food-related quality of life and symptoms, as measured by the short Crohn’s Disease Activity Index. Following the diet also decreased pro-inflammatory (e.g., serum amyloid A, C-reactive protein) and lipid markers (e.g., leptin) and increased markers involved in mucosal healing (e.g., proteins involved in endothelial cell development and DNA repair) in levels closer to those of healthy household controls.¹

Potential Mechanisms by Which the Mediterranean Diet is Beneficial in IBD

Unless there is a contraindication, the Mediterranean diet (MED) is widely adopted for IBD prevention and treatment. In the general population and first-degree relatives of patients with IBD, MED has shown a protective role in reducing the risk of IBD. In patients with IBD, MED is associated with symptom and inflammatory improvement and with maintaining low fecal calprotectin levels in quiescent disease. Additional health benefits of MED include good tolerance, improved quality of life, better metabolic health, and increased gut microbiome composition and diversity. To achieve better outcomes, MED should be supervised by an IBD dietitian in a personalized way based on individual needs, preferences, adverse reactions to food, type of symptoms and severity, and psychologic complications.²

The rationale that supports the role of MED in IBD is based on the following old and novel mechanisms:^3,4

• Promoting a diverse gut microbiome enriched in beneficial microbial groups (e.g., butyrate-producing bacteria) and depleted of potential pathogenic microorganisms (e.g., Dialister spp., Escherichia coli)
• Having anti-inflammatory properties through polyphenols and dietary fats
• Modulating oxidative stress
• Increasing organic compounds, vitamin derivatives, metabolites associated with folate synthesis, and microbial by-products of polyphenol fermentation
• Decreasing metabolites associated with sphingolipid metabolism, which takes part in inflammatory metabolic routes in IBD
• Reducing stress hormones, such as cortisol and aldosterone

‍Fasting-Mimicking Plant-Based Diet as Adjunctive Therapy to Medications in Moderate-Severely Active UC

Therapeutic diets for patients with UC have lagged behind CD. New data from a pilot single-blinded randomized trial by Oriana Damas, MD, and colleagues from the University of Miami Health System showed that two 5-day cycles of a low-calorie, high-fiber (plant-based) diet that mimics fasting may improve clinical response to medications in patients with moderate-severely active UC. 

The sample included patients who were starting a new advanced therapy (as a second or third-line drug) with or without steroids or mesalamine. Between the two cycles, patients were able to eat whatever they wanted. The rationale for this feeding regime is that it has been shown to enhance antitumor immune responses, decrease autophagy, partially reverse inflammation, and increase protective microbial populations in animal models.

Each of the two cycles consisted of one day of a low-calorie plant-based diet (1,100 calories/day, 11% plant-based protein sources, 46% from mono- and polyunsaturated fats, and 43% from complex carbohydrates) followed by five days of a very low-calorie plant-based diet (725 calories/day, 9% protein, 44% fat, and 47% carbohydrates). Patients also received a daily electrolyte mix. The diet was gluten- and dairy-free without any artificial preservatives and was administered in commercial diet kits. Patients in the control group received standard regular dietary advice with low fiber plus advanced medical therapy⁵

Patients who received the fasting-mimicking plant-based diet (n=9) plus the advanced medications showed a higher decrease in the severity of symptoms assessed by the Simple Clinical Colitis Activity Index (SCCAI), as compared to patients who only received the advanced medical therapy (n=12) (mean decrease of SCCAI in the intervention group: 4.4 versus 1.61 in the control group). These findings show that UC inflammation is responsive to diet interventions, even in very active disease, and diet can enhance response to medical therapy, even in short defined intervals.

Across the study period, an improvement in well-being and a decrease in inflammatory marker serum amyloid A protein, blood in stool, and urgency were found, accompanied by a trend towards a decrease in fecal calprotectin. While some patients on the diet intervention reported nausea, no weight loss was observed at the end of the week 8.⁵

Fermented Foods: Hype or Worth Addition to the Diet?

While fermented foods such as yogurt, kimchi, and sauerkraut have been consumed by humans for millennia, scientists have started understanding their health benefits recently. Fermented foods may have anti-inflammatory properties based on recent findings showing that consuming 6 servings per day of fermented foods for a 10-week period led to a reduction of 19 inflammatory compounds in healthy adults.⁶ Among the reasons why fermented foods are healthy staples is because they contain microbially produced metabolites that are beneficial for us.

Jacob Allen, PhD, from the University of Illinois at Urbana showed fermented foods may be a potential source of microbial metabolites, such as aryl-lactates, which regulate the immune system involving aryl hydrocarbon receptor (AhR) activation. The AhR has important functions in intestinal health and is involved in regulating mucosal immunity, repairing the gut barrier, and controlling gut movements through the enteric nervous system. IBD is characterized by a reduced microbial-induced AhR activity, and members of the Allen lab are working on increasing aryl-lactate production in yogurt, sauerkraut, and other fermented foods as a means to increase AhR activity that could potentially downregulate intestinal inflammation when ingested.⁷

Navigating Nuances in Diet Management of Noninflammatory Symptoms and IBD Complications

All FODMAPs are not Equal

Food is probably the main trigger for symptoms in patients with IBD, and one in every three patients with IBD in remission experiences IBS-like symptoms.⁸ While a high FODMAP diet is associated with an altered gut microbiome, gut barrier disruption, and increased mast cell activation, William Chey, MD, FACG, AGAF, FACP, RFF, from the University of Michigan presented new data showing not all dietary FODMAPs are equal. Fructans -found in wheat, rye, garlic, artichokes, and inulin- and galacto-oligosacharides (GOS) -found in beans, lentils, and chickpeas- were the two FODMAP groups that were most likely to trigger recurrent symptoms in patients with IBS who responded to the low FODMAP diet.⁹ In line with these findings, Prashant Singh, MD, from the University of Michigan and colleagues showed a 4-week ‘FODMAP-simple’ restriction phase (eliminating solely fructans and GOS) was well tolerated and improved abdominal symptoms in the majority of IBS-D patients, with an efficacy similar to the traditional low FODMAP diet.¹⁰

These findings suggest that a low FODMAP diet with a simplified or more targeted restriction phase is feasible and can overcome the challenges of following of the traditional low FODMAP diet (i.e., restrictive, time-consuming, risk of long-term continuation of restrictive phase, costly, and risk of micronutrient deficiencies).

Are there Alternatives to the Low FODMAP Diet for Gastrointestinal and Psychological Symptoms of IBS?

 Heidi Staudacher, PhD Adv APD RNutr from the Food & Mood Centre at Deakin University in Australia updated the role of whole diet interventions as alternative and patient-friendly approaches to the low FODMAP diet. The Traditional Dietary Advice diet, which has some overlap with the low FODMAP diet and promotes healthy eating patterns while reducing the intake of fatty/spicy foods, caffeine, and alcohol and limiting fresh fruit to three portions per day and gas-producing foods, showed 30-40% response rates in IBS.¹¹

A low-carbohydrate, high-fat diet (mean carbohydrate intake of 50 g/day), consisting of vegetables and berries, dairy products, fish, shellfish, eggs, chicken, pork, and beef, may lead to similar symptom relief (71%) as compared to the low FODMAP diet (76%), with both being more effective than medications, to treat the main symptom of IBS (58%).¹²

The Mediterranean diet is also a potentially feasible option for managing IBS symptoms. It is more inclusive and easy to follow than the low-carbohydrate diet. New findings from Staudacher and colleagues found that a Mediterranean diet for 6 weeks improves gastrointestinal and psychological symptoms in patients with IBS.¹³

Overall, supervision by a dietitian is key for diet delivery and monitoring, which contributes to efficacy of dietary interventions in patients with IBS.

 While restrictive diets such as the low FODMAP and the low carbohydrate diets are efficacious for IBS, they do come with challenges, including a negative impact on the gut microbiome, poor diet quality, an increased risk of disordered eating, and poor feasibility in people with mental health conditions.¹⁴ 

Up to 53% of patients with IBD may follow overly restrictive diets that may increase the risk of avoidant and restrictive food intake disorders (ARFID).¹⁵ Micaela Atkins, MD, from Mass General for Children shared some best practices for assessing eating disorders in patients with IBS-like symptoms, including the SCOFF questionnaire*, the Nine Item Avoidant/Restrictive Food Intake disorder screen (NIAS) questionnaire, and the 24-hour dietary recall. In the absence of a questionnaire, some examples of sensitive questions that may help explore patients’ eating habits include: “Have you ever felt like food was an issue for you?”, “How much time, mental energy and effort do you spend around eating and food choices?”, and “Do eating or food decisions get in the way of your ability to live the life you want to?”.

*SCOFF stands for:

S - Do you make yourself Sick because you feel uncomfortably full?

C - Do you worry you have lost Control over how much you eat?

O - Have you recently lost more than One stone in a three-month period?

F - Do you believe yourself to be Fat when others say you are too thin?

F- Would you say Food dominates your life?

Nutrition Tips for Short Bowel Syndrome and Intestinal Failure 

Crohn’s disease complicated by ileal resection may lead to the development of short bowel syndrome, which results from the loss of a significant length of the small intestine (less than 180 cm). This leads to malabsorption of fluids, electrolytes, and nutrients and may lastly favor chronic intestinal failure. Francisca Joly, MD PhD, from Beaujon Hospital in France, acknowledged that the ultimate goal in adults with intestinal failure is achieving nutritional autonomy or intestinal rehabilitation. Dietetic optimization of these patients requires trained healthcare professionals (including dietitians) and will depend on the remaining length of the small intestine and drinking and diet recommendations.¹⁶

Nutritional support for restoring intestinal function during temporary small bowel interruption with intestinal failure includes chyme reinfusion therapy, enteral, or parenteral nutrition.^17-19 The dietetic management in short bowel syndrome with intestinal failure will vary depending on the severity of intestinal failure and whether the patient has an intact colon in continuity. For instance, treatment for the high-output stoma starts with the patient restricting the total amount of oral hypotonic fluid (water, tea, coffee, and fruit juices). Individualized nutritional advice is central to improving clinical outcomes in patients with intestinal failure and seeks to guide the patient in eating and drinking with a stoma or fistula while reducing parenteral nutritional dependency and improving quality of life.²⁰             

Probiotics and Direct-to-Consumer Microbiome Tests in IBD

 Many individual variables can impact how a person responds to diet, all of which must be taken into account when dietitians give dietary advice to patients. This explains why there is huge variability in the benefits of microbiome-targeted interventions such as probiotics. Their efficacy depends on host factors (e.g., gut transit time), species and strain, following the probiotic regimen properly, probiotic delivery in a matrix, study design, sample size, the gastrointestinal disorder for which it is indicated, and the specific symptoms we are aiming to benefit.

Kevin Whelan, PhD RD, from King’s College London showed in a recent systematic review that some probiotic species and strains may offer benefits for IBS symptoms. While there is a rationale for probiotics' therapeutic application in IBD based on their mechanisms of action on the immune system, gut barrier, and gut microbiome dysbiosis, data for the use of probiotics in IBD is less clear. Weak evidence suggests that probiotics may induce remission in active UC, while data on probiotics in Crohn’s disease is limited.²¹

Examining the gut microbiome offers the potential to predict which individuals will respond to diet. Recent data presented by Whelan showed that specific volatile organic compounds in feces can explain 25% of the variation in response to a low FODMAP diet and 30% of the variation in response to a probiotic.²² But while studying the microbiome in the research setting helps understand why not all patients with digestive disorders respond to the diet, it is still early to routinely recommend microbiome tests to guide dietary choices.

A direct-to-consumer microbiome test can identify the types of microbes in your gut, but the results may not provide clear guidance on the best diet or food supplements for improving gut health or preventing IBD. Recently, a group of experts under the auspices of the American Gastroenterological Association published a commentary raising concerns about the benefits and harms of microbiome tests for consumers.²³

Microbiome tests can help monitor patients over time when other relevant data are provided. However, several challenges need to be addressed before implementation in clinical practice:

• Defining the microbiome associated with health in order to recognize the abnormal microbiome
• Uniformizing methodologies to study the microbiome
• Considering the context (diet, environment, and systemic parameters such as gut permeability, inflammation, and oxidative stress) to define if a particular microbiome is healthy or not

References:^‍‍

<sup>1. Hazime H. A low fat, high fiber dietary intervention in Crohn’s disease patients improves serum proteomic and metabolomic patterns reflecting improvements in systemic inflammation and mucosal healing. Oral communication within the session “Clinical insights into the role of diet in IBD”. 18 May 2024. Digestive Disease Week® (DDW) 2024, Washington, D.C.
2.Godny L, Dotan I. Is the Mediterranean diet in inflammatory bowel diseases ready for prime time? J Can Assoc Gastroenterol. 2023; 7(1):97-103. doi: 10.1093/jcag/gwad041.
3. Godny L. Mechanistic implications of the Mediterranean diet in patients with newly diagnosed Crohn’s disease – multi-omic analysis of a prospective cohort. Oral communication within the session “Clinical insights into the role of diet in IBD”. 18 May 2024. Digestive Disease Week® (DDW) 2024, Washington, D.C.
4. Haskey N, Ye J, Raman M, et al. (2024, May 18-21). An exploration of the Mediterranean Diet on the fecal metabolome in individuals with quiescent ulcerative colitis [Guided Poster Session, P1890] Digestive Disease Week® (DDW) 2024, Washington, D.C
5. Damas OM. Intervals of a plant-based, low-calorie diet improve clinical symptoms compared with usual diet in patients initiating medications for ulcerative colitis. Oral communication within the session “Clinical insights into the role of diet in IBD”. 18 May 2024. Digestive Disease Week® (DDW) 2024, Washington, D.C
6. Wastyk HC, Fragiadakis GK, Perelman D, et al. Gut-microbiota-targeted diets modulate human immune status. Cell. 2021; 184(16):4137-4153.e14. doi: 10.1016/j-cell-2021.06.019</sup>.
<sup>7.Kasperek MC, Velasquez Galeas A, Caetano-Silva ME, et al. Microbial aromatic amino acid metabolism is modifiable in fermented food matrices to promote bioactivity. Food Chem. 2024; 454:139798. doi: 10.1016/j.foodchem.2024.139798.
8. Gîlcâ-Blanariu GE, Drug V, Stefânescu G, et al. (2024, June 17-19). Irritable bowel syndrome-type symptoms among patients with quiescent inflammatory bowel disease. [Guided Poster Session, P019 - abstract code: IBS19430-70]. 4th edition of IBS Days 2024, Bologna, Italy.
9.Eswaran S, Jencks KJ, Singh P, et al. All FODMAPs aren’t created equal: results of a randomized reintroduction trial in patients with irritable bowel syndrome. Clin Gastroenterol Hepatol. 2024. doi: 10.1016/j.cgh.2024.03.047.
10.Singh P, Chey SW, Nee J, et al. Is a simplified, less restrictive low FODMAP diet possible? Results from a double-blind, pilot randomized controlled trial. Clin Gastroenterol Hepatol. 2024. doi: 10.1016/j.cgh.2024.04.021.
11.British Dietetic Association. Irritable bowel syndrome (IBS) and diet. Available on: https://www.bda.uk.com/resource/irritable-bowel-syndrome-diet.html
‍12.Nybacka S, Törnblom H, Josefsson A, et al. A low FODMAP diet plus traditional dietary advice versus a low-carbohydrate diet versus pharmacological treatment in irritable bowel syndrome (CARIBS): a single-centre, single-blind, randomised controlled trial. Lancet Gastroenterol Hepatol. 2024; 9(6):507-520. doi: 10.1016/S2468-1253(24)00045-1
13. Staudacher HM, Mahoney S, Canale K, et al. Clinical trial: A Mediterranean diet is feasible and improves gastrointestinal and psychological symptoms in irritable bowel syndrome. Aliment Pharmacol Ther. 2024; 59(4):492-503. doi: 10.1111/apt.17791
14. Staudacher HM, Black CJ, Teasdale SB, et al. Irritable bowel syndrome and mental health comorbidity – approach to multidisciplinary management. Nat Rev Gastroenterol Hepatol. 2023; 20(9):582-596. doi: 10.1038/s41575-023-00794-z.
15 Fink M, Simons M, Tomasino K, et al. When is patient behavior indicative of avoidant restrictive food intake disorder (ARFID) vs reasonable response to digestive disease? Clin Gastroenterol Hepatol. 2022; 20(6):1241-1250. doi: 10.1016/j.cgh.2021.07.045.
16.  Buchman AL. Etiology and initial management of short bowel syndrome. Gastroenterology. 2006; 130(2 Suppl 1):S5-S15. doi: 10.1053/j.gastro.2005.07.063.
17.  Koelfat KVK, Picot D, Chang X, et al. Chyme reinfusion restores the regulatory bile salt-FGF19 axis in patients with intestinal failure. Hepatology. 2021; 74(5):2670-2683. doi: 10.1002/hep.32017.
18.  Picot D, Layec S, Seynhaeve E, et al. Chyme reinfusion in intestinal failure related to temporary double enterostomies and enteroatmospheric fistulas. Nutrients. 2020; 12(5):1376. doi: 10.3390/nu12051376.
19.  Nikoupour H, Theodorou A, Arasteh P, et al. Update on surgical management of enteroatmospheric fistulae in intestinal failure patients. Curr Opin Organ Transplant. 2022; 27(2):137-143. doi: 10.1097/MOT.0000000000000960.
20.  Culkin A, Gabe SM, Madden AM. Improving clinical outcome in patients with intestinal failure using individualised nutritional advice. J Hum Nutr Diet. 2009; 22(4):290-8. doi: 10.1111/j.1365-277X.2009.00954.x.
21.  So D, Quigley EMM, Whelan K. Probiotics in irritable bowel syndrome and inflammatory bowel disease: review of mechanisms and effectiveness. Curr Opin Gastroenterol. 2023; 39(2):103-109. doi: 10.1097/MOG.0000000000000902.
22.  Rossi M, Aggio R, Staudacher HM, et al. Volatile organic compounds in feces associate with response to dietary intervention in patients with irritable bowel syndrome. Clin Gastroenterol Hepatol. 2018; 16(3):385-391. doi: 10.1016/j.cgh.2017.09.055.
23. Prados A. World Microbiome Day 2024: the knowns and unknowns of the potential of gut microbiome for personalized nutrition advice. Gut Microbiota for Health. European Society of Neurogastroenterology and Motility. Available on: https://www.gutmicrobiotaforhealth.com/world-microbiome-day-2024-the-knowns-and-unknowns-of-the-potential-of-gut-microbiome-for-personalized-nutrition-advice/Godny L. Mechanistic implications of the Mediterranean diet in patients with newly diagnosed Crohn’s disease – multi-omic analysis of a prospective cohort. Oral communication within the session “Clinical insights into the role of diet in IBD”. 18 May 2024. Digestive Disease Week® (DDW) 2024, Washington, D.C.Godny L. Mechanistic implications of the Mediterranean diet in patients with newly diagnosed Crohn’s disease – multi-omic analysis of a prospective cohort. Oral communication within the session “Clinical insights into the role of diet in IBD”. 18 May 2024. Digestive Disease Week® (DDW) 2024, Washington, D.C.</sup>

‍Dr. Andreu Prados is a science and medical writer specializing in making reliable evidence of non-prescription therapeutics for gastrointestinal conditions understandable, engaging and ready for use for healthcare professionals and patients.

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Dr. Natasha Haskey is a clinical scientist and Registered Dietitian with over 20 years of practical experience in nutrition therapy for IBD.  

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Stay informed of the latest news in nutrition and IBD.

 A new article focusing on what is new in nutritional therapies for IBD management, nuances to consider in dietary recommendations for patients with IBD, and why taking care of gut microbiome matters for determining the efficacy of nutritional interventions. Stay tuned for upcoming news!