by Bianca Garilli, ND
Inflammatory bowel disease (IBD) is characterized by chronic inflammation in the digestive tract and can be classified into two main conditions: ulcerative colitis (UC) and Crohn’s disease (CD). Both of these debilitating diseases involve similar symptoms including bloody diarrhea, abdominal pain and cramping, fever, fatigue, and unintended weight loss.1
The two disease processes, although overlapping in many ways, differ in their pathophysiology:1-2
- CD: This disease can affect any part of the gastrointestinal (GI) tract and is characterized by intermittent inflammation resulting in deep fissure-like ulcers. These ulcers, often referred to as granulomas, span across multiple layers of the digestive tract wall. CD manifestations are not solely limited to the GI tract but can also affect the skin, eyes, joints, and biliary system.
- UC: This disease typically presents with mucosa prone to easy bleeding and which contains small, superficial ulcers. UC is usually limited to the large intestine and rectal mucosa and extraintestinal manifestations are not as frequent as in CD.
IBD prevalance has risen from 2 million adults in 1999 to ~3 million (or 1.3% of US adults) in 2015.3 IBD is a “complex polygenic disease” with a multifactorial pathogenesis including T-cell dyregulation, gut dysbiosis, environmental factors, and dietary factors; genetic susceptibility also comes into play, with 200+ genes linked to IBD risk.4 The two most influential risk factors for IBD are thought to be the gut microbiome and diet.4
Diets that are high in animal fats, refined carbohydrates, and omega-6 fatty acids but low in fruits, vegetables, fiber, and micronutrients have been associated with an increased risk of IBD.5 Animal models indicate that high intake of saturated fats and emulsifiers from processed foods may increase IBD risk.4-5 While diet may impact the onset and progression of IBD, research also shows it may be key to manage IBD.5 In particular, specialized diets such as the specific carbohydrate diet, semi-vegetarian diet, and anti-inflammatory diet have been associated with beneficial clinical responses in IBD.4-5
More recently, the autoimmune protocol (AIP) has come into the spotlight as a potential dietary and lifestyle intervention approach that may improve IBD outcomes. To test the efficacy of the AIP in patients with IBD, a small, open-label, uncontrolled study including 15 participants (average age: 45; 78% female) with active CD (n=9) and UC (n=6) was conducted at Scripps Clinic, Division of Gastroenterology in La Jolla, CA.4 Prior to the start of the study, 8 of the 9 CD participants had active disease with visible erosions or ulcers on endoscopic evaluation, and 5 of these 8 had a fecal calprotectin (FC) level of >50 mcg/g.4 CRP levels were elevated in 33% of participants with CD at baseline.4 In the UC group, all 6 individuals had active disease at the start of the study, while 5 had elevated FC at baseline.4
Participants were first placed on a 6-week elimination phase with staged elimination of grains, legumes, nightshades, dairy, eggs, coffee, alcohol, nuts and seeds, refined/processed sugars, oils, and food additives, followed by a 5-week maintenance phase in which the aforementioned food groups remained eliminated. Office visits occurred at baseline and study conclusion, and labs were run at baseline, week 6, and week 11. To track mucosal healing, endoscopy, radiology, and/or biomarker assessment were completed at baseline and the completion of the study.4 The AIP in the study also included:4
- Certified health coach support
- Registered dietitians for 1-on-1 nutritional support
- Counseling on importance of support groups and assistance in grocery shopping and food preparation
- Education on specific topics such as sleep, nutrient density, fermented foods, stress management, bone broth, physical activity, and avoidance of nonsteroidal anti-inflammatory drugs
- Email and private Facebook group coaching and dietary counseling
Clinical IBD remission was achieved at week 6 by 11/15 (73%) study participants (6 CD; 5 UC), and all 11 maintained their remission during the subsequent 5 weeks (maintenance phase) of the study.4 Other significant results include:4
- Decrease in FC (baseline: 701 mcg/g; week 11: 139 mcg/g) among patients with baseline FC >50 mcg/g
- 7 participants experienced mucosal improvement from endoscopy at week 11
- 2 of 3 participants were able to discontinue their oral steroid medications
- 2 participants independently opted to discontinue their oral mesalamine therapy, yet still achieved IBD improvement or clinical remission
Researchers noted, “this proportion of participants with active IBD…achieving clinical remission by week 6 rivals that of most drug therapies for IBD…our results suggest that dietary modification can be used as an adjunct to conventional IBD therapy, even among those with moderate-to-severe disease.”4
Why is this Clinically Relevant?
- Diet is a modifiable risk factor and therapeutic intervention approach for IBD
- Diets that limit pro-inflammatory foods and emphasize anti-inflammatory foods may improve IBD symptoms and support clinical remission
- Lifestyle interventions implementing an AIP diet may promote IBD remission, and accompanying daily living interventions are likely important to the overall success of the protocol4
- HCPs working with IBD patients should consider targeted nutrition therapies, specifically the AIP, as an important adjunctive therapy for mild, moderate, and severe disease states4
- Mayo Clinic. Inflammatory Bowel Disease. https://www.mayoclinic.org/diseases-conditions/inflammatory-bowel-disease/symptoms-causes/syc-20353315. Accessed July 9, 2018.
- Annahazi A, Molna T. Pathogenesis of ulcerative colitis and crohn’s disease: similarities, differences and a lot of things we do not know yet. J Clin Cell Immunol. 2014;5:253.
- CDC. Inflammatory Bowel Disease Data and Statistics. https://www.cdc.gov/ibd/data-statistics.htm. Accessed July 9, 2018.
- Konijeti GG, Kim N, Lewis JD, et. al. Efficacy of the autoimmune protocol diet for inflammatory bowel disease. Inflamm Bowel Dis. 2017;23(11):2054–2060.
- Lewis JD, Abreu MT. Diet as a trigger or therapy for inflammatory bowel diseases. Gastroenterology. 2017;152(2):398-414.