Jason Hou, MD, on Incorporating Diet Into IBD Practice

While there is a plethora of data linking diet and inflammatory bowel disease (IBD), data on the efficacy of specific dietary programs in managing IBD, Jason K. Hou, MD, MS, told the attendees at the AIBD regional meeting in Houston, Texas, June 22.

Dr Hou is director of the IBD Program and associate professor at Baylor College of Medicine in Houston, Texas.

He reported on a systematic review of 19 studies that evaluated diet patterns of 2609 patients prior to their diagnosis, to determine if there may be a dietary trigger that could cause IBD. The review found that consumption of polyunsaturated fats may increase the risk of developing IBD by 2 to 6 times, while omega-6 fats and total fat intake can raise the risk of IBD 2 to 3 times and meats by 3 to 4 times. Consumption of adequate fiber and fruit can decrease the risk by 1 to 2 times, he noted.

To incorporate dietary guidance into an IBD practice, Dr Hou advised recognizing that food avoidance is very common among patients with IBD. He said, “Some 75% of patients modified their diet at diagnosis and about 82% of patients restrict food to prevent flares.”

Clinicians should proactively engage with patients about food, he suggested. “Ask patients about what they ate the day before, what they eat when they are away from their homes.”

Dr Hou stressed the importance of becoming familiar with therapeutic diets for IBD, including:

• Exclusive Enteral Nutrition (EEN)
• Specific Carbohydrate Diet (SCD)
• Crohn’s Disease Exclusion Diet (CDED)
• Low FODMAP diet
• Anti-inflammatory diet (IBD-AID)
• Autoimmune protocol diet (AIP)
• CD-TREAT

Exclusive enteral nutrition is used most widely in treating pediatric patients with Crohn’s disease and is “nearly as effective as prednisone” in initiating remission, he explained. However, it is very difficult to maintain and may not be as effective with adult patients,

Partial enteral nutrition (PEN) is not as effective as EEN but “it is a pragmatic approach to enteral nutrition” and may have a role in combination with other dietary approaches.

The Specific Carbohydrate Diet (SCD) was initially proposed in 1924 as a treatment for celiac disease, Dr Hou stated. It is based on the theory that some carbohydrates are poorly absorbed, perhaps due to bacterial/yeast overgrowth or small intestine injury. “Some studies suggest it may reduce GI symptoms in IBD but there are no placebo-controlled studies” to support this, he said. It is also rather difficult to maintain and patients can be put at risk for nutritional deficiency.

Dr Hou reviewed the DINE-CD randomized controlled trial in which 194 adult patients with mild to moderate Crohn’s disease were randomized 1:1 to the SCD vs the Mediterranean diet (MD). In this study patients continued on medical therapy while receiving 6 weeks of prepared food. They then followed the diet independently for another 6 weeks.

The primary outcome was symptomatic remission at week 6; 43.5% of patients following the MD and 46.5% of patients following the SCD achieved this outcome. At week 12, differences between the two diets remained statistically insignificant (42.4% SCD group, 40.2% in the MD group.)  

The Crohn’s Disease Exclusion Diet (CDED) is another option, Dr Hou explained. This “whole-food” diet is designed to reduce foods that are hypothesized to induce dysbiosis and increase intestinal permeability. The 3-phase diet plan begins with exclusion of several foods and use of PEN; then foods are added back and PEN decreases to allow for continued remission. The response to CDED is similar to the response rate for EEN, but the diet has only been tested in small studies with no placebo control.

The Low FODMAP (fermentable oligo-, di- and mono-saccharides and polyols) diet has been studied primarily among patients with irritable bowel syndrome and has demonstrated some improvement of symptoms among patients with disorders of gut-brain interaction. However, Dr Hou observed, a systematic review “failed to provide adequate evidence in terms of quality and quantity to support recommendations” for the low FODMAP diet in IBD.

To integrate diet into an IBD clinical practice, Dr Hou recommended finding an IBD-focused dietitian to work with patients to create

Dr Hou and colleagues were involved in development and pilot testing of the IBD: Nutrition Care Pathway, utilizing the modified Malnutrition Universal Screening Tool (mMUST) to identify patients who are malnourished or at risk of malnutrition. The NCP then provides steps to be taken to evaluate the patient and interventions to reduce the risk of malnutrition. Among 2388 patients with IBD screened in the pilot program, 72% were determined to be low-risk (mMUST 0), 10% medium-risk (mMUST 1) and 18% high-risk (mMUST ≥2).

Dr Hou stated that clinicians should “be aware of potential food as medicine approaches for IBD,” and take steps to integrate nutrition into their practices.

Rebecca Mashaw

Hou JK. The role of diet in inflammatory bowel disease. Presented at: Advances in Inflammatory Bowel Disease regional meeting. June 22, 2024. Houston, Texas.