None listed
Conditions
Brief summary
Dietary fibre (DF) is important in our diet. It helps reduce the risk of constipation, coronary heart disease, stroke, type 2 diabetes and colorectal cancer. However, the previous Adult Nutrition Survey 2008/09 reported that inadequate DF intake is a dire issue in New Zealand (NZ). It is thought that food cost is the most important factor on food purchasing decisions, which may have steered many individuals away from healthy eating. Bread is the main food source of DF in the New Zealand population, and is considered as one of the cheaper food products to purchase in NZ. Further, bread is an ideal vehicle to incorporate cereal bran into bread to increase DF content and ultimately, can improve DF intake in the NZ population. Being one of the cheaper cereal by-products, rice bran is gaining its popularity due to its high DF content of 20-51%, which is doubled than that of oat bran. Several studies have suggested to consider defatted rice bran (DRB) as a source of value-added food product. Defatting increases the proportion of DF in rice bran by increasing its insoluble fibre. Only a few human studies have been undertaken on rice bran. The focus of these studies has been on metabolic health, gastrointestinal transit or modulation of the gut microbiota composition and function in either healthy adults, those with diarrhoea and constipation, colorectal cancer survivors or individual with high risk of colorectal cancer. No trials, to date, have studied the effects of defatted rice bran (DRB) in bread on the composition and function of the gut microbiota in healthy adults with inadequate DF intake.? As the recommended intake for DF differs between genders, this study will therefore, assess these effects in healthy adults with inadequate DF intake following the consumption of three (females), four (males) slices of DRB bread over 28 days.
Interventions
The main intervention will consist of three (females) and four (males) slices of white bread fortified with defatted rice bran (DRB) per day, which will be eaten for 4 weeks. The main intervention consists of white toast bread with 18% replacement of the flour (cereal) weight and provides 9 g (females) and 12 g (males) of total fiber per day. Of the 9 - 12 g of fiber in three to four slices of DRB bread, 2.6 g (females), 3.4 g (males) will be fiber from wheat, and 6.7 (females), 8.9 g (males) wi
The main intervention will consist of three (females) and four (males) slices of white bread fortified with defatted rice bran (DRB) per day, which will be eaten for 4 weeks. The main intervention consists of white toast bread with 18% replacement of the flour (cereal) weight and provides 9 g (females) and 12 g (males) of total fiber per day. Of the 9 - 12 g of fiber in three to four slices of DRB bread, 2.6 g (females), 3.4 g (males) will be fiber from wheat, and 6.7 (females), 8.9 g (males) will be from DRB. Unfortified white bread will be the placebo. Participants will not be informed of the ingredients in the bread until study completion to maintain blinding. The study duration is a nominal total of 14 weeks; 2-week lead-in phase, 4-week intervention phase 1, 2- week washout, 4 -week intervention phase 2, and 2-week follow-up phase. The 2-weeks lead-in phase requires participants to record their bowel motion and bread intake on a developed app every day (from study enrolment until study completion); complete a questionnaire in regards to their socioeconomic status and general wellbeing, complete a non-consecutive 3-day food diary (2nd week of lead-in phase). Participants will provide a faecal sample, and fast overnight for 9 hours one day prior to their baseline visit (2nd week of lead-in phase). Participants will undergo anthropometry measurements (height, weight, BMI, waist circumference), blood pressure measurement, provide a blood sample, complete a set of questionnaires in regards to their mental and physical health, general well-being, and clinical variables, ingest diagnostic devices (only a subset of participants, i.e. 15 participants) in capsule form, and blue food dye to measure whole gut transit time during their baseline visit (2nd week of lead-in phase). Participants will repeat all of the aforementioned baseline visit procedures and on their post-intervention visit 1, baseline phase 2, post-intervention visit 2, and follow up. Participants will receive compensation form of vouchers during their follow-up visit. Attendance of clinic visits and completion of questionnaires will also be assessed to measure study adherence. The data generated with the questionnaires will be correlated to the data of the biological samples, such as the population and genetic composition of the microbiota, the abundance of metabolites, as well as physiome data from blue food dye and/or Atmo gas sensing capsules to determine the differences between the two groups.
Sponsors
University of Otago
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
All
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
1) Low baseline intake of dietary fibre i.e. Males: under 22 g/day and females under 18 g/day 2) No history of bowel disease 3) Non-smokers 4) Not on fibre supplement consumption during the last month prior screening 5) Regular bread consumption 6) Adults (18-65) 7) Good general health 8) A body mass index (BMI) between 18 and 35.
Exclusion criteria
1. Inability to give informed consent 2. Indication of inability to comply with study procedures 3. Antibiotic use within the last month 4. Hypersensitivity to wheat or rice 5. Pregnant, breastfeeding, or planning a pregnancy in the three months post selection/during (study period) 6. Alarm features associated with bowel habits such as recent changes in bowel habits (onset < three months), rectal bleeding, sudden weight loss, occult blood in stool, anaemia, anal fissures, bleeding haemorrhoids, and family history of gastrointestinal cancer at an early age 7. Known significant gut disorder and disease: Chronic constipation or diarrhoea, irritable bowel syndrome (IBS), Inflammatory Bowel Disease (IBD), diverticulitis, coeliac disease, or previous bowel resection 8. Chronic disease such as cardiovascular disease, cancer, renal failure, previous upper or lower GI surgery other than cholecystectomy or appendectomy, neurological conditions such as multiple sclerosis, spinal cord injury, or stroke 9. Known systemic conditions (heart disease, kidney disease, diabetes, metabolic syndrome, psychological disorder) that could influence the gut directly or through medication use such as diabetes, opiate, or non-steroidal anti-inflammatory drugs use) 10. Fasting blood glucose less than or equal to 6.0 mmol/L 11. Laxative, pre- and probiotic use, and inability or unwillingness to stop using for the seven days before sample collections. Non-exclusion Criteria Diagnosed and stable systemic conditions for more than three months. The use of selective serotonin reuptake inhibitors, tricyclics, or NSAIDs will be permitted if the medication has been used continually and the condition has been stable for more than three months. Stable and controlled diabetes for more than three months Inability to swallow capsules (for the ATMO sub study)
Outcome results
None listed