What is Crohn’s disease?

Crohn’s disease is a chronic disease of the gastrointestinal (GI) tract. It is characterized by lesions (sores) and inflammation within the lining of the GI tract, anywhere from the mouth to the anus. Crohn’s disease affects both children and adults.

What are the symptoms of Crohn’s disease?

Typical symptoms include diarrhea, abdominal pain, nausea, weight loss, and fatigue. People with Crohn’s disease may also experience rectal bleeding, fever, skin rashes, and joint pain. The symptoms are recurrent, with alternating periods of remission (symptoms absent) and relapse (symptoms present).

Why does Crohn’s disease cause malnutrition?

Malnutrition is a problem in as many as three out of every four people with Crohn’s disease. Lesions in the mouth, loss of appetite, nausea, and other GI symptoms can make it difficult for people with Crohn’s disease to eat enough. Changes in the microbiome – the variety of microorganisms in the GI tract – and intestinal inflammation reduce the absorption of consumed nutrients. These uncomfortable symptoms and changes in the GI tract cause weight loss in adults, poor weight gain in children, and nutritional deficits.

What causes Crohn’s disease?

Researchers are studying the possible causes of Crohn’s disease. They believe the cause is likely multifactorial, with environmental, genetic, and immune factors contributing to the development of the disease.

Environmental factors include changes in the number and diversity of microorganisms that live within a person’s GI tract (the microbiome). An increase in harmful bacteria relative to beneficial bacteria in the microbiome has been seen in people who:

· Consume a diet rich in saturated fat and poor in fiber (the typical Western diet)

· Are exposed to antibiotics during childhood

· Have a smoking addiction

Some harmful microorganisms can invade the lining of the GI tract and cause inflammation. One in three people with Crohn’s disease have been found to have an increase in the microorganism Escherichia coli, a bacteria known to invade the intestinal lining.

More than one in 10 people with Crohn’s have a genetic variation that increases their risk of developing the disease. Some of these genes affect the structure of the intestinal lining, while others influence how the body deals with microorganisms.

What are the treatment options for Crohn’s disease?

While there is no known cure for Crohn’s disease, treatments can reduce or eliminate symptoms. The goal of treatment is to reduce inflammation, promote healing of the GI tract lining, and eliminate symptoms.

When treatment causes the symptoms to stop, this is referred to as inducing remission. When the GI tract lining begins to heal, this is called deep remission. Induction therapy refers to treatments that induce remission. Maintenance therapy refers to treatments that help to maintain remission.

Dietary therapy and medications that reduce inflammation are the mainstays of therapy. The healthcare team may also prescribe pain medication, antidiarrheal medication, and antibiotics. Surgery to remove sections of the intestine is sometimes performed in people who do not respond to medications or dietary therapy.

What are the nutritional treatment options for Crohn’s disease?

A typical Western diet can contribute to an increase in harmful bacteria and inflammation in the GI tract. Conversely, proper dietary therapy can help to heal the intestinal lining and improve the intestine’s ability to absorb nutrients in patients with Crohn’s disease.

What is exclusive enteral nutrition?

One such diet is called exclusive enteral nutrition, or EEN. In EEN, the patient is prescribed a diet of liquid protein formula for six to eight weeks. The patient drinks the formula by mouth or administers it through a tube placed in the nose (nasogastric tube) or mouth (orogastric tube). The formula provides all daily caloric and nutrient needs. No solid foods are consumed.

Some of the benefits of EEN are:

· An induction remission rate of up to 80%

· Nutritional support

· Reasonable cost

· An effective alternative to corticosteroid and immunosuppressive therapy, which have many side effects and are not tolerated in all patients

· Improved bone metabolism and bone mass in children and adolescents

For all these reasons, EEN is the first-line treatment in children with Crohn’s disease. It is preferable to corticosteroids, an effective medical treatment, because corticosteroids can cause growth suppression in children and adolescents.

EEN has been used for adult patients with similar success. However, many adult patients struggle to keep to a purely liquid diet. As many as 50% of adult patients stop following the diet before it has had the chance to work. Non-compliance may be due to:

· Poor motivation

· Lack of support

· Unpalatable formula

Completing a course of EEN may prevent the reoccurrence of symptoms for as long as two years. Unfortunately, benefits to the microbiome are quickly lost after the reintroduction of solid food.

What is the Crohn’s disease exclusion diet?

It has been suggested that the absence of certain harmful food products, not the EEN itself, might be responsible for reducing intestinal inflammation. The Crohn’s disease exclusion diet (CDED) is based on excluding certain foods associated with damage of the intestinal lining and growth of harmful bacteria. CDED consists of high-quality proteins and foods low in fat and rich in complex carbohydrates, such as:

· Chicken

· Eggs

· Potatoes

· Rice

· Fruits

· Vegetables

These foods can be combined with partial enteral nutrition (PEN) as a calorie and nutrient supplement. A CDED regimenmay look like this:

· First six weeks: 50% of calories from the short list of foods listed above, plus 50% of calories from PEN

· Weeks six to 12: Increase in calories from food as new foods are slowly added to the allowed list, plus a gradual decrease in PEN from 50% to 25% of total calories

· After 12 weeks: Maintenance phase with a variety of allowed foods. PEN continues to provide 25% of calories.

Several studies have found that at six weeks, remission has been induced in 70-75% of patients following CDED. At 12 weeks, 75-80% of those in remission at six weeks were still in remission. With the option for solid food, compliance and tolerance of the CDED tend to be greater than with EEN.

Final Thoughts

Crohn’s disease is a chronic inflammatory disease of the GI tract. Diets that support a healthy gut biome and reduce inflammation can successfully induce remission in many patients. In adult patients, a diet that is enjoyable is more likely to be followed over the long term.

Dietary Treatment of Crohn’s Disease