None listed
Conditions
Brief summary
The only dietary therapy to treat Crohn's disease (CD) is exclusive enteral nutrition (EEN), which has shown to heal the gut in a proportion of patients. EEN is a treatment that involves removing all food and replacing it with a nutritionally-complete liquid formula, usually for a six-week period. This observation shows that there is something in diet that is involved in driving or alleviating inflammation in CD. The exact way in which EEN works is unknown, so we cannot design a diet that may be used in place of EEN. One hypothesis that fits the observation of EEN treating CD is that certain dietary emulsifiers, often not found in enteral formulas, contribute to gut inflammation. Emulsifiers are commonly found in natural and manufactured foods and help to keep food stable by preventing the separation of water and oil. Animal and laboratory-based studies have shown that certain emulsifiers cause a leaky gut (i.e., they break down the intestinal barrier) and cause inflammation. This has never been investigated in humans. This proposal aims to address the main research question: Are dietary emulsifiers associated with breakdown of the intestinal barrier and inflammation? Research is underway to design low and high emulsifier diets for application in trials, including compilation of a database of manufactured foods. Based on the designed diets, we plan to conduct the first human dietary trial to examine the effects of a low emulsifier diet compared with a high emulsifier diet on highly sensitive markers of intestinal barrier function and inflammation in healthy subjects. All food will be provided to subjects in a cross-over design (i.e., subjects have both diets). At the end of each diet period, subjects will give blood, urine and faecal samples, which will be analysed for subtle markers of barrier function and inflammation that have already been established to represent a leaky gut in healthy people. This includes analysis bacterial translocation (passage of bacteria from gut to other parts of the body). Based on the outcomes of this trial, to determine duration and level of emulsifiers, a second trial providing low emulsifier or a safe comparator diet in patients with CD will be conducted.
Interventions
Study 1 in healthy subjects - in a cross-over design, healthy subjects will be provided 4 weeks of a low emulsifier diet and 4 weeks of a high emulsifier diet with a minimum of 3 weeks washout between the diets. A low emulsifier diet is developed by the researchers at The Alfred and based on knowledge of natural emulsifiers in addition to identified additive emulsifiers on packaged food. Researchers at The Alfred have a database of commercially available packaged food and their ingredients lis
Study 1 in healthy subjects - in a cross-over design, healthy subjects will be provided 4 weeks of a low emulsifier diet and 4 weeks of a high emulsifier diet with a minimum of 3 weeks washout between the diets. A low emulsifier diet is developed by the researchers at The Alfred and based on knowledge of natural emulsifiers in addition to identified additive emulsifiers on packaged food. Researchers at The Alfred have a database of commercially available packaged food and their ingredients lists, which identify presence or absence of emulsifiers. A high emulsifier diet is matched nutritionally, but will use foods that contain emulsifiers. For example, two commercially available wholemeal breads that do and do not already contain emulsifiers will be provided during the dietary interventions. Unfortunately, quantification of emulsifiers in food is not possible, so 'high' and 'low' emulsifier diets will describe foods that have identifiable sources of emulsifiers or not. Research dietitians will be recruiting and arranging all food for the intervention is provided to participants. The diets will comprise of food cooked, individually portioned, vacuum-packed and frozen by our research chef. All food is readily available in supermarkets and already consumed by community. Adherence will be based on food diaries provided to participants and any returned food. On the last day of each of the intervention, the subjects will visit The Alfred Hospital and be provided a very high fat meal providing 56-60 g fat. The high fat meal will be similar to that used in previous studies investigating markers of intestinal injury and comprise of a sausage and cheese sandwich with hash browns and emulsifier-free peanut butter.
Sponsors
Alfred Health
Study design
Allocation
Randomised controlled trial
Intervention model
Other
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject)
Eligibility
Sex/Gender
All
Age
18 Years to 60 Years
Healthy volunteers
Yes
Inclusion criteria
Healthy subjects - those that believe themselves to be healthy with no known gastrointestinal condition.
Exclusion criteria
Study 1 - peanut allergy, recent use (previous 2 weeks) of probiotics, antibiotics, supplemental prebiotics, restrictive diets (including vegetarian) or any medication including complimentary and alternative medicines that might influence gut function or microbiota, coeliac disease and/or other gastrointestinal disease, malnutrition, and/or psychological illness, or inability to speak or read English or give informed consent.
Outcome results
None listed