Autoimmune Protocol (AIP) Diet for Crohn's: A Patient Guide

In a small but encouraging 2017 pilot trial, 73 percent of participants with active inflammatory bowel disease achieved clinical remission by week 6 of the Autoimmune Protocol (AIP) diet (1) - but the study had only 15 patients and no control group, so the results are preliminary.

If you have spent time in Crohn's disease forums or patient communities, you have probably seen the Autoimmune Protocol diet mentioned with either passionate enthusiasm or careful skepticism. Both reactions are understandable. The AIP diet is one of the most restrictive elimination frameworks out there, and the published evidence is genuinely promising - but also genuinely small. This article walks through the actual trial data, explains exactly what the autoimmune protocol diet Crohn's disease protocol involves, and offers a practical, safety-first approach for anyone considering it.

Key Takeaways

• In a 2017 pilot trial at Scripps Clinic, 73% (11 of 15) of participants with active IBD achieved clinical remission by week 6 on the AIP protocol (1)
• Fecal calprotectin, an objective marker of intestinal inflammation, dropped from a mean of 471 to 112 by week 11 in the same cohort (1)
• Quality-of-life scores improved significantly, climbing from 46.5 at baseline to 54.0 by week 3 and continuing to rise through week 11 (2)
• The evidence base is still very small - all published AIP-IBD data comes from a single center with 15 patients and no control group (1, 4)
• AIP is not a substitute for medication; participants in the pilot continued their prescribed therapies throughout the study (1)
• Children, adolescents, pregnant patients, and anyone who is malnourished should not attempt AIP without professional supervision

What Is the Autoimmune Protocol (AIP) Diet?

The Autoimmune Protocol diet is a structured elimination and reintroduction framework originally developed as an extension of the Paleolithic diet. Its core theory is straightforward: remove foods believed to act as antigens, drive mucosal inflammation, or worsen gut dysbiosis, then systematically rebuild the diet based on each individual's tolerance. The result is a personalized eating plan built on data from your own body rather than generic dietary advice.

AIP unfolds in three phases. The first is an elimination phase lasting approximately six weeks, during which a long list of potentially inflammatory foods is removed. The second is a staged reintroduction phase, where eliminated foods are brought back one at a time over several days each. The third is a maintenance phase - a fully personalized way of eating based on what your body tolerated during reintroduction.

How AIP Differs from Other IBD Diets

If you have already explored dietary approaches for Crohn's, you may be wondering how AIP compares to other structured diets. As we covered in our Paleo diet guide for IBD, the standard Paleo diet removes grains, legumes, dairy, and processed foods - but AIP goes further by also eliminating eggs, nuts, seeds, nightshade vegetables, coffee, and food additives. The Specific Carbohydrate Diet (SCD) takes a different angle, focusing on carbohydrate complexity rather than immune triggers. The Crohn's Disease Exclusion Diet (CDED) is the most studied in pediatric IBD and combines partial enteral nutrition with specific whole foods. And the IBD-AID diet modifies the SCD with added prebiotics and probiotics. Each approach has its own evidence base and philosophy - AIP's distinguishing feature is its focus on autoimmune triggers specifically, and its emphasis on systematic, individualized reintroduction.

What the Research Says About AIP for Crohn's Disease

The published evidence for the AIP diet for Crohn's comes primarily from a research group at Scripps Clinic in San Diego. The data is encouraging, but it is essential to understand its limitations before drawing conclusions.

Konijeti 2017 Pilot Trial

The foundational study is a 2017 single-arm pilot trial led by Dr. Gauree Konijeti at Scripps (1). Fifteen adults with active Crohn's disease or ulcerative colitis followed the AIP protocol for 11 weeks. The first six weeks were the elimination phase, followed by a five-week maintenance period.

The results were striking. By week 6, 73 percent of participants (11 of 15) achieved clinical remission. In the Crohn's disease subgroup, mean Harvey-Bradshaw Index scores dropped from 7 at baseline to approximately 3.4 by week 11. In the ulcerative colitis subgroup, mean partial Mayo scores fell from 5.8 to approximately 1.0 (1).

Objective markers of inflammation also improved. Mean fecal calprotectin - a direct measure of intestinal inflammation that does not depend on how patients feel - dropped from 471 to 112 by week 11. Among the seven patients who had follow-up endoscopy, six showed endoscopic improvement (1).

Some participants were even able to reduce or discontinue certain medications under their physicians' supervision during the study (1). However, it is crucial to note that all participants continued their prescribed IBD therapies throughout the trial - AIP was used as an add-on, not a replacement.

Quality of Life Findings

A follow-on analysis by Chandrasekaran and colleagues (2019) looked specifically at how AIP affected patients' quality of life (2). Using the Short Inflammatory Bowel Disease Questionnaire (SIBDQ), the researchers found that mean scores climbed from 46.5 at baseline to 54.0 by week 3 and continued rising through week 11. Patients reported improvements in sleep, energy levels, and bowel-movement regularity.

RNA and Inflammation Biomarkers

In a separate substudy of the same cohort, intestinal tissue RNA expression was analyzed in the ulcerative colitis patients (3). The results showed 324 significantly altered genes on AIP, with downregulation of inflammatory T-cell pathways and upregulation of regulatory T-cell and mucosal-healing pathways. While this is mechanistically interesting, it involved very few patients and the findings need replication.

What a 2024 Review Concluded

A 2024 systematic review published in Metabolism Open evaluated AIP across multiple autoimmune conditions, including IBD (4). The authors concluded that AIP shows early promise but that current studies are "grossly underpowered." They called for larger randomized controlled trials before AIP can be recommended as a standard approach. This is an honest and important assessment - the pilot data is hopeful, but 15 patients from a single center without a control group is not enough to draw definitive conclusions.

The AIP Protocol: What to Eat and What to Avoid

Understanding exactly what goes into an AIP elimination phase is important, because this is one of the most restrictive dietary protocols in clinical use. The restrictions are not arbitrary - each category is removed based on its theoretical potential to trigger immune activation or disrupt the gut barrier.

Foods Eliminated in the First Phase

During the elimination phase (approximately 6 weeks), the following are removed completely:

• Grains - all types, including wheat, rice, corn, and oats
• Legumes - beans, lentils, peanuts, soy
• Dairy - all forms, including butter and ghee
• Eggs - whole eggs and any egg-containing products
• Nightshade vegetables - tomatoes, peppers, eggplant, potatoes (sweet potatoes are allowed)
• Nuts and seeds - all varieties, including cocoa and seed-based spices
• Coffee and alcohol
• Refined and processed sugars
• Industrial seed oils - canola, soybean, corn, safflower
• Food additives - emulsifiers, thickeners, artificial sweeteners
• Nonsteroidal anti-inflammatory drugs (NSAIDs) - ibuprofen, naproxen, and similar medications, which can damage the intestinal lining (1)

Foods Emphasized

What remains is more generous than the elimination list might suggest:

• Fresh vegetables (except nightshades) - leafy greens, cruciferous vegetables, root vegetables, squash
• Fruit in moderation
• Fresh fish and seafood
• Pasture-raised meats and poultry
• Bone broth
• Fermented foods - sauerkraut, kimchi, kombucha (dairy-free)
• Healthy oils - olive oil, avocado oil, coconut oil
• Fresh herbs and non-seed spices (turmeric, ginger, cinnamon)

Reintroduction Phase

After the elimination period, foods are reintroduced one at a time. Each new food is tested over 3 to 7 days, during which you track symptoms carefully - digestive changes, energy levels, joint pain, skin reactions, and any return of disease symptoms. If a food causes no problems across that window, it is considered tolerated and stays in the diet. If it triggers symptoms, it goes back on the avoid list.

The reintroduction order matters. Most AIP protocols suggest starting with foods that are least likely to cause problems (such as egg yolks or seed-based spices) and working toward those with higher trigger potential (such as dairy or gluten-containing grains).

Maintenance Phase

The maintenance phase is what makes AIP different from a one-size-fits-all diet. By the end of reintroduction, every patient has their own personalized list of safe and trigger foods. Some people discover they tolerate eggs and rice just fine but react to nightshades. Others find dairy is the primary trigger. The maintenance phase is simply living with that knowledge - eating the foods that work for you and avoiding the ones that do not.

Potential Benefits Beyond Symptom Control

Beyond the headline remission numbers, the AIP research suggests several additional benefits worth noting:

• Objective inflammation reduction - fecal calprotectin and CRP decreased in some patients, suggesting that AIP may affect underlying inflammation, not just symptom perception (1)
• Quality-of-life improvements - sleep, energy, and bowel regularity all improved in the quality-of-life analysis (2)
• Medication reduction - some patients in the pilot were able to reduce or discontinue certain medications under physician supervision, though this should never be attempted without medical guidance (1)
• Individual trigger identification - the structured elimination and reintroduction process can reveal specific food triggers that generic dietary advice ("eat more fiber," "avoid spicy food") would never identify

Risks, Limitations, and Who Should Not Try AIP Alone

Enthusiasm for AIP needs to be balanced with an honest assessment of its risks and the gaps in the evidence.

The evidence is very preliminary. All published AIP-IBD data comes from a single research center, involves only 15 patients, has no control group, and has relatively short follow-up. A 2024 review confirmed that current studies are grossly underpowered (4). It is possible that the improvements seen in the pilot were partly due to the placebo effect, the attention and support participants received, or natural disease fluctuation.

AIP is highly restrictive. Removing grains, legumes, dairy, eggs, nuts, seeds, and nightshades simultaneously creates a real risk of unintended weight loss and micronutrient deficiencies - particularly in patients whose absorption is already compromised by active Crohn's disease. Iron, calcium, vitamin D, B12, and zinc are all at risk if the diet is not carefully planned.

Not appropriate for everyone. AIP should not be used as a first-line strategy for severe active flares, stricturing disease, or patients who are already malnourished. Children, adolescents, and pregnant patients should not attempt AIP without both an IBD-experienced dietitian and a gastroenterologist involved.

Coffee elimination may not suit everyone. Some patients with bile acid diarrhea find that coffee actually helps manage symptoms. Eliminating it reflexively may do more harm than good in those cases.

AIP is not a substitute for medication. This point cannot be emphasized enough. The participants in the Konijeti pilot stayed on their prescribed IBD therapies throughout the study (1). AIP was studied as an add-on to medical treatment, not as a replacement for it.

How to Try AIP Safely If You Choose To

If you have read the evidence, understand the limitations, and still want to explore AIP, here is a practical framework for doing it safely:

1. Talk to your gastroenterologist first. Get baseline labs including CRP, ferritin, vitamin D, B12, folate, and fecal calprotectin. These give you objective numbers to compare against later.

2. Work with a registered dietitian who has IBD experience, ideally one familiar with elimination diets. A dietitian can help you plan nutritionally complete meals despite the restrictions and catch deficiencies before they become problems.

3. Continue your prescribed IBD medications. Use AIP as an add-on, exactly as it was studied. Never stop or reduce medication without your doctor's explicit guidance.

4. Track symptoms, weight, and stool patterns weekly during the elimination phase. A simple journal or app works. Look for trends, not day-to-day fluctuations.

5. Plan reintroduction carefully. Introduce one food every 3 to 7 days with clear criteria for what counts as a pass or fail. Write it down - memory is unreliable when tracking subtle symptoms over weeks.

6. Recheck labs and calprotectin at 8 to 12 weeks. This is the only way to know whether the diet is actually affecting inflammation or just changing how you feel. Symptoms and objective inflammation do not always move together in IBD.

7. Be honest with yourself about sustainability. If the elimination phase is causing significant stress, weight loss, or social isolation, those costs may outweigh the potential benefits. A less restrictive approach - such as the Mediterranean diet or a modified elimination plan - might be a better fit.

Frequently Asked Questions

Is the AIP diet safe for people with Crohn's disease?

For adults with mild-to-moderate Crohn's disease who maintain their prescribed medications, AIP appears to be generally well tolerated based on the 2017 pilot trial (1). However, it is highly restrictive and carries risks of nutrient deficiencies if not supervised. Always work with your gastroenterologist and a registered dietitian before starting.

How long does the AIP elimination phase last?

The standard AIP elimination phase lasts approximately six weeks. In the Konijeti pilot trial, participants followed the elimination phase for six weeks, then transitioned to a five-week maintenance period (1). Most clinical remissions in the study were achieved by the end of the six-week elimination.

Can I do the AIP diet while on biologics or immunosuppressants?

Yes - and in fact, you should continue your medications. In the published trial, all participants stayed on their prescribed IBD therapies throughout the study (1). AIP was tested as a complement to medical treatment, not a replacement. Never stop or adjust medications without your doctor's guidance.

What is the difference between the AIP diet and the Paleo diet?

AIP is a stricter version of the Paleo diet. While standard Paleo removes grains, legumes, dairy, and processed foods, AIP also eliminates eggs, nuts, seeds, nightshade vegetables, coffee, alcohol, and food additives. AIP adds a structured reintroduction phase that Paleo does not include, making it more of a diagnostic tool for identifying individual food triggers.

Will the AIP diet cure my Crohn's disease?

No dietary approach has been shown to cure Crohn's disease. The AIP pilot trial showed that some patients achieved clinical remission and reduced inflammation while on the diet (1), but the study was small, had no control group, and did not follow patients long term. AIP may help manage symptoms and identify food triggers, but it is not a cure.

Is AIP appropriate for children with Crohn's disease?

Children and adolescents should not attempt AIP without close supervision from both a pediatric gastroenterologist and a registered dietitian experienced with IBD. Growing bodies have higher nutritional demands, and the severe restrictions of AIP's elimination phase could lead to growth faltering or nutrient deficiencies if not carefully managed.

How do I know if the AIP diet is actually reducing my inflammation?

Symptom improvement alone is not enough to confirm that inflammation is decreasing - symptoms and objective inflammation do not always correlate in IBD. Ask your gastroenterologist to check fecal calprotectin and CRP at baseline and again at 8 to 12 weeks. In the pilot trial, fecal calprotectin dropped from 471 to 112 by week 11, providing objective evidence of reduced intestinal inflammation (1).

References

1. Konijeti GG, Kim N, Lewis JD, et al. Efficacy of the Autoimmune Protocol Diet for Inflammatory Bowel Disease. Inflammatory Bowel Diseases. 2017;23(11):2054-2060. Read study

2. Chandrasekaran A, Groven S, Lewis JD, et al. An Autoimmune Protocol Diet Improves Patient-Reported Quality of Life in Inflammatory Bowel Disease. Crohn's and Colitis 360. 2019. Read study

3. Chandrasekaran A, Molparia B, Akhtar E, et al. The Autoimmune Protocol Diet Modifies Intestinal RNA Expression in Inflammatory Bowel Disease. Crohn's and Colitis 360. 2019;1(3):otz016. Read study

4. Pardali EC, Gkouvi A, Gkouskou KK, et al. Autoimmune protocol diet: A personalized elimination diet for patients with autoimmune diseases. Metabolism Open. 2024. Read study

5. Autoimmune Protocol Diet and Inflammatory Bowel Disease - ClinicalTrials.gov. View trial record

6. UC and the Autoimmune Protocol Diet. WebMD. 2023. Read article