Exclusive enteral nutrition
Exclusive enteral nutrition is a dietary treatment for active Crohn’s disease that was first used in the 1970s. “Enteral” is an adjective that describes movement through the gastrointestinal tract either via the mouth or a tube. Exclusive enteral nutrition (EEN) refers to the exclusive or sole use of nutrition formula that can be delivered orally (drank) or via a tube. For this treatment we use a commercially produced, nutritionally complete (that is it contains all the protein, carbohydrate, fat, vitamin and minerals that your body needs) formula drink that, in the treatment of Crohn’s disease, is usually prescribed for a period of 6 - 8 weeks. The treatment involves drinking the formula multiple times per day with the exclusion of solid foods and most usual drinks. EEN works to reduce Crohn’s symptoms and inflammation whilst promoting gut healing and is used to bring you into remission. EEN is an effective treatment for ~80% of people with active Crohn’s who choose to try it. If EEN works for you then you can use it again in the future to treat another flare. One of my patients recently had a flare and got in contact with me to use EEN again because they found it “very effective last time”. Second time around it is working for them again too.
Nutritional formula
The nutritional formulae we use for EEN are drinks that contain all the nutrition that your body needs to sustain and repair itself. The nutrition in these drinks is easy to digest and absorb and it comes in a concentrated form. Most people need to drink 6 - 9 servings or cartons (200ml) per day. The exact amount you need depends on your weight and activity level.
These drinks are partially or fully funded by the government (depending on your age and the type of drink you use). At the moment children under the age of 18 years can get ready-to-drink cartons (like a small juice carton) or powdered drinks fully funded to use for EEN. Adults however, have to pay a surcharge on the ready-to-drink cartons, but can use fully funded powdered (where you need to mix each drink yourself) option.
History of EEN
Nutritional formulae have been available for many years. The first high quality research studies using EEN to treat adult active Crohn’s were done in the 1980s. These were large studies done mostly in Europe that compared EEN against corticosteroids to treat Crohn’s flares. The nutritional formulae were usually elemental formulae (drinks that contain the most simple form of nutrients so that no digestion is required) which tasted bitter and had a strong aftertaste and because of this were often delivered via a tube that went from the person’s nose into their stomach. Some of the studies asked people to drink the formulae. Most of these studies found that steroids were more effective than EEN at treating active Crohn’s. A limitation of these studies was that 20 - 60% of people using EEN didn’t finish the study. Many of those people withdrew because they couldn’t tolerate the unpleasant tasting formula or found it difficult to live with a tube in their nose for 6 - 8 weeks. Based on these studies from the 1980s it was decided that adults with active Crohn’s should be treated with steroids rather than EEN.
In the late 1990s and early 2000s the first high quality studies of EEN in children with active Crohn’s were published. One of the differences between the adult and paediatric research studies was that the children were given a different type of nutritional formula (a polymeric or whole protein formula) and were only given the nutritional formulae by a tube if they couldn’t manage to drink it. Another difference is that the children probably had more support from their family and medical team (as opposed to adults who likely weren’t still living with their parents!). These studies from the 1990s and 2000s showed that children tolerated EEN much better than in the adult studies and that EEN was as effective as steroids at getting Crohn’s into remission. In children, EEN also improves micronutrient levels in the body, helps to increase muscle and fat, improves height growth and has no side effects. In contrast to this, corticosteroids can have unpleasant side effects in some people and the use of repeated doses of steroids in children negatively affects growing bones and can lead to stunting and brittle bones. Based on these early studies and those that followed later in the 2000s, EEN is the treatment of choice for children when they are newly diagnosed with Crohn’s and, if they respond well to the treatment (which 80% of children do), EEN can be used to treat flares of Crohn’s instead of using corticosteroids.
EEN works so well in children, so why wouldn’t it work in adults?
There is now renewed interest in using EEN in adults with active Crohn’s. My PhD research in Christchurch from 2013 to 2016 looked into this question. Aside from the fundamental question of whether EEN was as effective at treating Crohn’s in adults as children, my research also looked into external factors related to the likelihood of someone completing the 8 week course. You can read my published scientific articles on my research page. My conclusions were that EEN works really well if people can stick to it. In my research ~80% of people who completed the treatment went into remission. Recent research conducted in Australia with adults agrees with my findings and there are more and more reports being published that also show that EEN works to reduce inflammation and get into Crohn’s remission in adults.
But, like many of the previous studies with adults, my research found that not everyone can complete EEN treatment. A third of the participants in my research were older teenagers who were still at high school. This group of adults seemed to find EEN particularly challenging. Food plays such an important role in our lives. Not only do food and drinks nourish our body but they also nourish our soul and are an important part of most social occasions. EEN is a mentally and socially challenging treatment for most people. How do you feel about the idea of going without any food for at least 6 weeks? What if you knew it was a very effective and healthy way to get your Crohn’s into remission? I believe that everyone should be given the option to try EEN but know that it may not be a treatment that suits everyone and that’s ok!
Why does it work?
So EEN works to get Crohn’s into remission, but how or why does it work?
Unlike a drug treatment that is often designed to target one particular metabolic pathway, EEN works on multiple levels. Professor Andrew Day, paediatric gastroenterologist at Christchurch Hospital, has been involved in research here in Christchurch and also in Sydney that has shown that the nutrients in nutritional formulae have anti-inflammatory properties and reduce pro-inflammatory chemicals in the gut lining. Whether it is specific nutrients, or the combination of nutrients is not entirely known yet. EEN also has an impact on the gut microbiota. Stool samples from people on EEN, including the lucky people who took part in my PhD research, show us that the microbial load decreases and the type of microbes present change too.
In addition to direct impacts on the gut and the gut environment, EEN improves general nutritional intake and, if needed, can help people to re-gain lost weight. Many research studies in IBD show that a well-nourished body heals better than a body that isn’t getting enough nutrition. The nutritional formulae we use for EEN contain easy to absorb nutrients that need minimal digestion which makes it easier for your body to get the nutrition that it needs. Furthermore, the formulae help to reduce inflammation and the gut is much better at absorbing nutrients and the body is ready to use those nutrients when there is less inflammation present. The readily available nutrition in EEN means that symptoms that you associate with eating and digestion, such as pain and diarrhoea during or after eating, improve quickly while on EEN. The lack of food bulk going through the digestive system also helps to reduce the frequency of diarrhoea.
There is still more research needed to fully understand how nutritional formulae treat inflammation and help to heal the gut. My other blogs discuss how natural plant chemicals have anti-inflammatory properties and I think that further work is also needed to investigate how nutritional formulae can be further enhanced with such plant chemicals to make them even better!
Who should use EEN?
Similar to medication tolerance, some people thrive and do very well on EEN whilst for others the thought of going without normal foods and drinks is very unappealing.
I recently published some work from my PhD that looked into whether personality is associated with tolerance of EEN. See the publication accepted by the journal here or on my website under research or click here for the abstract. We observed that people who are more conscientious were more likely to complete an 8 week treatment with EEN than people who were less conscientious. A conscientious person tends to start and finish tasks, remembers to take their medication daily and be quite organised.
If EEN is not for you, there are other dietary treatments that may suit you more. For example, you could use a shorter course of EEN (e.g. two weeks) and then use a dietary treatment that combines the nutritional formula with a restricted solid food diet. Or you may choose to skip EEN altogether and just use a combination of formula drinks and a restricted diet. There are options and this is where my knowledge and skills in this area are most relevant!
How can you access een to treat Crohn’s?
Most gastroenterologists know that EEN can treat flares of child and adult Crohn’s disease so if you are interested in using EEN to treat a flare discuss it with your them and ask for a referral to a dietitian who is experienced using the treatment (such as me at Gut Nutrition) or you can self-refer to Gut Nutrition to get started straight away!
I have used EEN, or a combination of nutritional formula and food, to treat Crohn’s flares with more than 50 people. I can support you throughout your treatment with EEN and am authorised to prescribe the nutrition formula drinks. I offer an initial appointment to get started along with regular phone or email follow-up during the treatment to check that you are tolerating the treatment and that it is working. After your 6- 8 week course of EEN I provide support to reintroduce food with the aim of moving on to eating a healthy and varied diet as possible for you. To find out more get in contact here.