Determining the Potential of Wholegrain Wheat and Rye to Improve Gut HealTh (RIGHT)

A dietary intervention study designed as a randomized, controlled, parallel intervention of 6-weeks duration. A total of 75 participants will be included in the study and randomly allocated to one of three interventions (refined wheat, whoelgrain wheat or wholegrain rye). Clinincal examinations including anthropometric assessment, fecal, urine and fastign blood sampling, dietary assessment and a meal challenge will be done before (week 0) and after (week 6) the intervention. At timepoints week 0, 2, 4 and 6 questionnaires will be filled in concerning satisfaction with diet and gastrointestinal symptoms.

A dietary intervention study designed as a randomized, controlled, parallel intervention of 6-weeks duration. A total of 75 participants will be included in the study and randomly allocated to one of three interventions (refined wheat, whoelgrain wheat or wholegrain rye). The randomization will be stratified according to sex and sex-specific median habitual cereal dietary fibre intake (16g/d for men and 13g/d for women). The randomization will be done by means of a randomization generator of the webpage (http://www.randomization.com). Recruitment and randomization will take place continuously during the study period, and therefore randomization will be done as mixed block randomization. During the intervention study, participants are instructed to substitute all cereal products (e.g. bread, breakfast cereals, pasta) of their diet with the provided study products. The amount of provided study products will match the average intake of carbohydrate-rich products of the Danish population, which corresponds to ~200g of bread and cereal products per day. The participants will eat the study products in an ad libitum manner and b instructed to avoid other cereals in their diet including cake, biscuits, ready made meals and fast foods with the exception of White rice whis is allowed 1-2 times per week. Clinincal examinations including anthropometric assessment, fecal, urine and fastign blood sampling, dietary assessment and a meal challenge will be done before (week 0) and after (week 6) the intervention. At timepoints week 0, 2, 4 and 6 questionnaires will be filled in concerning satisfaction with diet and gastrointestinal symptoms.

Subjective sensations of gastrointestinal symptoms evaluated by questionnaires (100mm visual analogue scales)

Body weight and waist circumference, saggital abdominal diameter and body composition (fat mass and fat free mass assessed using DEXA)

Fasting and postprandial (every 30 minutes for 240 minutes) sensation of hunger, satiety, fullness, prospective food intake, thirst and well being

Fasting and postprandial (every 30 minutes for 240 minutes) concentrations of H2 in exhaled breath assessed using a Hydrolyzer

Intestinal permeability is assessed by urinary excretion of lactulose and mannitol for 4 hours and 24 hours following an oral load of 10g lactulose and 2 g mannitol

a weighted 4-day food record will be used to assess energy intake and macronutrient (protein, fat, carbohydrates and dietaru fiber) composition

Compliance, measured by fasting plasma alkylresorcinol concentrations will be used as a biomarker of wholegrain wheat and rye intake

Fasting plasma alkylresorcinol concentrations will be used as a biomarker of wholegrain wheat and rye intake

Inclusion Criteria: • Age: 30 - 65 years Body mass index (BMI): 25 - 32 kg/m2 Weight stable (<3 kg weight change during the last 6 months) Apparently healthy Informed consent signed Freezer capacity for 2 weeks bread provision Can attend all visits required for the study Exclusion Criteria: • Smoking on a daily basis Lactating (or lactating within 6 weeks prior to study start), pregnant (or pregnant within 3 months prior to study start) or wish to become pregnant during the study Diagnosed with any form of diabetes or CVD Reported chronic GI disorders Antibiotic treatment 3 month before study start and during the study Use of pre- or probiotic 1 month before study start and during the study Lack of cooperation and adherence to the protocol Use of prescription medication will be evaluated on an individual basis

Christensen L, Vuholm S, Roager HM, Nielsen DS, Krych L, Kristensen M, Astrup A, Hjorth MF. Prevotella Abundance Predicts Weight Loss Success in Healthy, Overweight Adults Consuming a Whole-Grain Diet Ad Libitum: A Post Hoc Analysis of a 6-Wk Randomized Controlled Trial. J Nutr. 2019 Dec 1;149(12):2174-2181. doi: 10.1093/jn/nxz198.

Vuholm S, Nielsen DS, Iversen KN, Suhr J, Westermann P, Krych L, Andersen JR, Kristensen M. Whole-Grain Rye and Wheat Affect Some Markers of Gut Health without Altering the Fecal Microbiota in Healthy Overweight Adults: A 6-Week Randomized Trial. J Nutr. 2017 Nov;147(11):2067-2075. doi: 10.3945/jn.117.250647. Epub 2017 Sep 27.

Suhr J, Vuholm S, Iversen KN, Landberg R, Kristensen M. Wholegrain rye, but not wholegrain wheat, lowers body weight and fat mass compared with refined wheat: a 6-week randomized study. Eur J Clin Nutr. 2017 Aug;71(8):959-967. doi: 10.1038/ejcn.2017.12. Epub 2017 Mar 22.