None listed
Conditions
Brief summary
Resection of the large bowel and creation of a new rectum or reservoir from the small bowel, termed ileoanal pouch, is the surgical treatment of choice for ulcerative colitis (UC) and familial adenomatous polyposis (FAP). Quality of life following pouch creation is generally good. However, a considerable number of patients have persistent pouch-related symptoms of increased frequency, urgency, leakage and incontinence. Additionally, around 40-50% of UC IPAA and 10-20% of FAP IPAA develop inflammation of the pouch, called pouchitis. The cause of pouchitis is not completely understood, but the effectiveness of antibiotics in treating pouchitis suggests that the pouch bacteria play a key role. One possible explanation is that there is an imbalance of key products of bacterial metabolism. On the negative side, hydrogen sulphide (H2S) is a gas (‘rotten egg gas’) produced from bacterial breakdown of undigested protein and processing of sulphates or sulphites that are used as preservatives in many foods. H2S is toxic at high concentrations to cells lining the gut. On the positive side, bacteria make short chain fatty acids (SCFA) as they process (ferment) carbohydrates. One of them, butyrate, is particularly important to maintain the health of the lining of the pouch. Butyrate’s ability to work is also inhibited by high concentrations of H2S. In patients with a pouch, increased H2S and decreased butyrate have been associated with an increase in problems associated with the pouch, particularly pouchitis. What we eat influences the ability of bacteria in the pouch to make H2S and butyrate. A limited number of studies have explored the use of dietary strategies in an attempt to improve pouch symptoms and reduce inflammation. No single strategy has been consistently effective. We recently conducted a pilot study to assess the tolerability and effectiveness of a diet called Monash Pouch diet. The diet strategies included (1) increasing readily fermentable fibre (inulin and oligosaccharides which encompass fructo- and galacto-oligosaccharides), (2) reducing osmotically active carbohydrates such excess fructose and polyols, (3) limiting excessive protein intake (including animal and plant protein) to (less than 100g/d), (4) reducing sulphur-containing protein intake, and (5) restricting intake of preservative. This diet was well tolerated by 80% of participants and was effective in improving pouch-related symptoms in all symptomatic patients along with improved inflammation as shown by a reduction of faecal calprotectin, a non-invasive marker of inflammation. Therefore, we have decided to follow this pilot study with a randomised study to assess its effectiveness in improving symptoms and inflammation as well as influence the pouch bacteria and their function in a beneficial way.
Interventions
Participants will attend a 1h session with the research dietitian to familiarise themselves with the dietary intervention at week baseline. They will then be sent all their food for the duration of the study in boxes of meals and frozen meals on a weekly basis for the 7 week intervention period. This will include a 1 week initial adaptation phase where they gradually increase their intake of fermentable fibre followed by a 6-week diet intervention. The study diets were designed by a research die
Participants will attend a 1h session with the research dietitian to familiarise themselves with the dietary intervention at week baseline. They will then be sent all their food for the duration of the study in boxes of meals and frozen meals on a weekly basis for the 7 week intervention period. This will include a 1 week initial adaptation phase where they gradually increase their intake of fermentable fibre followed by a 6-week diet intervention. The study diets were designed by a research dietitian with expertise in dietary interventions for pouch patients in conjunction with the research chef. The intervention diet consists of 5 principles: (1) A higher amount of readily fermentable fibre content (6g of oligosaccharides and 10g of resistant starch) (2) A reduced intake of foods high in excess fructose and polyols (<1.5 g/d) as used in previous dietary studies. (3) A daily protein intake; within the Australian guide to healthy eating / nhmrc RDI for protein intake (4) Limiting animal protein and concentrated protein sources as major of sources of sulphur containing amino acids whilst allowing intake of most dairy, legumes and plant-based protein sources as the main staples (to 30-40% of the daily protein intake) (5) Minimising intake of food preservatives derived from sulphates and sulphites. Suitable preservative-free products will be used instead. Adherence to the intervention will be monitored using food diary checklists and via direct questioning by the research dietitian.
Sponsors
Monash University
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
All
Age
18 Years to 75 Years
Healthy volunteers
No
Inclusion criteria
Patients with ileoanal pouch and a history of pouchitis Clinical Pouch Disease Activity Index (PDAI) greater than or equal to 3 Age 18-75 years Naïve or have limited prior knowledge for implementing a 5URE diet Amenable to complying to a dietary intervention Eligible for Medicare
Exclusion criteria
Inability to provide informed consent No history of pouchitis Clinical PDAI <3 Coeliac disease History of stricturing ileal or pouch inlet disease History of small bowel obstructions in the last 2 years Recent change, in the last 4 weeks of pouch-directed therapies, including oral or intravenous antibiotics, amino-salicylates, corticosteroids, immunosuppressive agents (thiopurines, methotrexate), and biologic agents (infliximab, adalimumab, ustekinumab, vedolizumab) Use of fibre, probiotic and/or prebiotic in the last 4 weeks Individuals following a predominantly plant-based or vegan diet Individuals not following a stable diet for less than 4 weeks Pregnancy, trying to become pregnant, breastfeeding.
Outcome results
None listed