The IBD Anti-Inflammatory Diet

This diet promotes probiotics and prebiotics to affect the microbiome

It’s understood that inflammatory bowel disease (IBD) is not caused by diet, yet there may be some interaction between diet and developing a favorable balance of the bacteria in the digestive system (the microbiome).

IBD is characterized by inflammation in the digestive system. However, because IBD is an immune-mediated condition, meaning that it is caused by an abnormal reaction by the immune system, it can also affect other areas of the body. IBD is thought to be caused by a complex interaction of genes that are associated with the disease and one or more environmental triggers.

Elimination diets might be helpful for some people with IBD in managing their symptoms. However, it’s strongly recommended that people with IBD work with a registered dietitian when looking to make changes to their diet. A dietitian can help sort through a diet plan and make personalized suggestions based on a patient’s preferences and nutritional needs. Diet restriction, without the help of a healthcare professional, could lead to malnutrition.

A person sitting on a counter and holding yogurt

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IBD and the Microbiome

The bacteria, fungi, viruses, protozoa, and other microorganisms that live in the human digestive tract are referred to as the microbiome. The microbiome is extremely complex and contains an estimated 100 trillion microorganisms. Every person’s microbiome is considered to be individual to them.

Diet, geographic location, and a host of other factors have an effect on the type of microorganisms in the microbiome and how many of each there are. However, there are some types of bacteria that are present in the digestive tract of most healthy people. It’s thought that about one-third of the microbiome is fairly consistent for all humans.

People with Crohn’s disease or ulcerative colitis, however, have a different makeup of bacteria in their digestive tract than people who don’t live with these forms of IBD. For that reason, it’s thought that a change in the microbiome may play a part in the development of IBD or in the development of inflammation.

When the microbiome is altered out of balance, it is called dysbiosis. The dysbiosis could be either because the microbiome is bumped away from its normal for some reason or because the immune system has an abnormal response to the microbiome. In mice used for the study of IBD, inflammation can be created in their intestine by making changes to their microbiome. Further, when microorganisms are taken from the microbiome of donors with IBD, the mice have even worsening colitis (inflammation in the large intestine).

Diet and IBD

The study of diet and the microbiome in people who live with IBD has been challenging due to several factors. Some studies have shown that a diet called exclusive enteral nutrition can be helpful for children with Crohn’s disease. In this diet, all of the calories the patient takes in are from liquid nutritional formula. These diets can be difficult to use in the long term, so there are variations being studied where between 25% and 50% of the diet is from a specific list of foods and the rest is the liquid nutrition. These diets are usually used for between six and 12 weeks and they can help induce remission for those than are able to tolerate them.

The theory behind why these diets work for some is that the person with IBD is not taking in foods that may negatively affect the microbiome. In some cases the microbiome is changed for those who are able to follow the diet. This leads to other theories and questions about how diet may be used for altering the microbiome in people with IBD and which type diet may be most useful.

The IBD Anti-Inflammatory Diet

One such diet that has been developed to help people with IBD is called the IBD anti-inflammatory diet (AID). The IBD-AID was developed as an adaptation of another popular diet, the Specific Carbohydrate Diet (SCD). The SCD was first described by Elaine Gottschall in her book, Breaking The Vicious Cycle: Intestinal Health Through Diet. Gottschall found that the symptoms of her daughter’s ulcerative colitis were helped through a change in diet. A simplified description of the SCD is that complex carbohydrates are eliminated for a time and eventually re-introduced back into the diet. The theory is that the change in diet helps to move the microbiome into a composition that promotes the growth of helpful bacteria.

The IBD-AID was developed by Barbara Olendzki, RD, MPH, associate professor of medicine in the Division of Preventive and Behavioral Medicine and director of the University of Massachusetts Medical School Center for Applied Nutrition and her colleagues. While some patients may find success with the SCD, others find it restrictive. The IBD-AID was developed to build on the principles of the SCD but be easier for patients to follow.

The IBD-AID is focused on adding probiotics and prebiotics to the diet, avoiding certain carbohydrates, and overall fostering appropriate nutrition. This means, in broad strokes, adding fermented foods and soluble fiber to the diet, while avoiding or eliminating heavily processed foods, and ensuring that daily vitamin and nutrient requirements are being met.

Probiotics are the microorganisms (such as bacteria and yeasts) that are found in fermented foods such as yogurt and sauerkraut. They are living and so when they’re eaten, they can help colonize the microbiome. Often they’re called the "good” bacteria or bugs, meaning that they are different from the types of bacteria that can cause infection and illness.

Prebiotics are fibers found in plants which humans can not digest. These fibers help feed the microorganisms in the digestive system and help those organisms to grow.

The IBD-AID is designed to be implemented in phases. There have been three or four phases of the IBD-AID described. The University of Massachusetts Center for Applied Nutrition describes three phases on their website. A published case report series from healthcare providers and researchers at the same institution used four phases. The foods allowed on the diet are different in each phase of the diet.

Phase I

The first phase is designed for those who may be experiencing symptoms of a flare-up, such as diarrhea, blood in the stool, urgency, pain, or frequent bowel movements. Some people with IBD find that they are less able to tolerate many different types of food when their IBD is more active.

In this phase, certain carbohydrates are eliminated, including refined or processed complex carbohydrates. Lactose-containing foods are also restricted, and certain fruits and vegetables are allowed if they are soft, well-cooked, or pureed and do not contain any seeds. The use of a blender to alter the texture of foods is encouraged. Yogurt and kefir are allowed, along with lean meats and all types of fish.

Phase II

This phase is designed for when the symptoms of a flare-up have improved but there are still some occurring. The food list in the second phase is designed to expand the allowed foods to include more fiber as well as those that contain probiotics and prebiotics. For instance, fermented foods are emphasized, along with soluble fiber (including bananas and oats), and pureed vegetables and nuts. The intent of this phase is to rebalance the microbiome.

Phase III

This phase is used when the symptoms of a flare-up have largely abated and bowel movements are back to what is generally considered in the normal spectrum. The University of Massachusetts defines this as "controlled and solid." The third phase of the diet adds in more greens (although stems may need to be avoided), kimchi, an expanded list of fruits, and more lean meats including beef, aged cheeses, and specific types of fats.

Phase IV

This phase is used in the case report research described below. People who do not have intestinal strictures (narrowing in sections of the intestines) could add in more fruits and vegetables, including cruciferous types like broccoli and cauliflower. The emphasis in this phase is on improving the absorption of nutrients and people are encouraged to alter the texture of foods (cooking, pureeing, grinding) as needed for managing their symptoms.

The Evidence for the IBD-AID

The use of the IBD-AID began with an initial study, called a pilot study. In this small study, 11 patients were given help in starting the IBD-AID during five nutrition sessions, as well as access to cooking classes. Patients were between the ages of 19 and 70 years old and followed the diet for four weeks. All patients noted a reduction in symptoms. The study authors noted that the diet has “potential” and called for randomized trials to continue studying the diet as adjunctive therapy for IBD.

In one case report series, 27 patients in Massachusetts with IBD gave the IBD-AID diet a try (13 who were offered the diet decided not to try it). Of the 27, 24 had a “very good” or “good” response to the diet, and three had a “mixed” response. All of the patients reported that their IBD symptoms were reduced and were able to discontinue one of their medications.

A study that was presented at an IBD-focused medical meeting (Crohn’s and Colitis Congress) showed that a majority of patients who tried the IBD-AID reported a decrease in disease severity. After eight weeks, 61% of patients on the diet who were following it at least 50% of the time had improvement and also had increased levels of the types of bacteria that produce short-chain fatty acids (SCFAs). SCFAs may help regulate inflammation in the gut.

More study is currently being done on the IBD-AID and other diets for use in people with Crohn’s disease or ulcerative colitis. This research will help in determining the utility of this diet and who might be helped through its use, as well as learning more about the actual structure of the diet. 

How a Dietitian Can Help With the IBD-AID

Diet is complicated and while patients are experts in their own bodies, diet can be confusing and it can be helpful to have a partner in figuring it out. Registered dietitians are trained in helping people who live with chronic illness in learning how to develop an eating plan.

A registered dietitian (RD or RDN) is a certified medical professional who can guide you in creating a personalized diet plan for IBD.

There are dietitians that specialize in digestive disease and even in Crohn’s disease and ulcerative colitis. Some IBD centers have a dietitian that works with IBD patients and in other cases, a referral to a provider that has experience with IBD patients may be helpful.

In many cases, only a few visits with a dietitian are needed to get started with developing a diet plan. After that, touch points can be used every so often to make changes to the diet plan, such as during a flare-up or when entering into remission.

Another important point to know about the IBD-AID is that it is continuing to evolve. For this reason, it's important to work with a healthcare team in order to be sure that it is implemented properly.

The University of Massachusetts has made a significant amount of information available through their IBD-AID web site, including a food list and daily menus, as well as answers to more detailed questions about how the diet differs from the SCD and what types of foods are allowed. However, this information is meant to learn more about the diet and to augment the help that patients are already receiving from their healthcare team.

A Word From Verywell

There is no one diet that will be helpful for everyone who lives with IBD. However, researchers are starting to hone in on how diet may affect IBD and what types of diets may be helpful in managing symptoms. Gone are the days where patients were told that their diet didn’t matter or that it was part of a valid treatment plan to fast or avoid eating. Diet is complex and needs to take a variety of factors into account, not only the IBD but also personal preferences and cultural considerations. That’s why diet needs to be personalized. While there is certainly some trial and error involved, that can be lessened through the use of a comprehensive diet plan developed with help from a dietitian.

8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Additional Reading

By Amber J. Tresca
Amber J. Tresca is a freelance writer and speaker who covers digestive conditions, including IBD. She was diagnosed with ulcerative colitis at age 16.